source: trunk/src/Scantable.cpp @ 2475

//
// C++ Implementation: Scantable
//
// Description:
//
//
// Author: Malte Marquarding <asap@atnf.csiro.au>, (C) 2005
//
// Copyright: See COPYING file that comes with this distribution
//
//
#include <map>

#include <atnf/PKSIO/SrcType.h>

#include <casa/aips.h>
#include <casa/iomanip.h>
#include <casa/iostream.h>
#include <casa/OS/File.h>
#include <casa/OS/Path.h>
#include <casa/Arrays/Array.h>
#include <casa/Arrays/ArrayAccessor.h>
#include <casa/Arrays/ArrayLogical.h>
#include <casa/Arrays/ArrayMath.h>
#include <casa/Arrays/MaskArrMath.h>
#include <casa/Arrays/Slice.h>
#include <casa/Arrays/Vector.h>
#include <casa/Arrays/VectorSTLIterator.h>
#include <casa/BasicMath/Math.h>
#include <casa/BasicSL/Constants.h>
#include <casa/Containers/RecordField.h>
#include <casa/Logging/LogIO.h>
#include <casa/Quanta/MVAngle.h>
#include <casa/Quanta/MVTime.h>
#include <casa/Utilities/GenSort.h>

#include <coordinates/Coordinates/CoordinateUtil.h>

// needed to avoid error in .tcc
#include <measures/Measures/MCDirection.h>
//
#include <measures/Measures/MDirection.h>
#include <measures/Measures/MEpoch.h>
#include <measures/Measures/MFrequency.h>
#include <measures/Measures/MeasRef.h>
#include <measures/Measures/MeasTable.h>
#include <measures/TableMeasures/ScalarMeasColumn.h>
#include <measures/TableMeasures/TableMeasDesc.h>
#include <measures/TableMeasures/TableMeasRefDesc.h>
#include <measures/TableMeasures/TableMeasValueDesc.h>

#include <tables/Tables/ArrColDesc.h>
#include <tables/Tables/ExprNode.h>
#include <tables/Tables/ScaColDesc.h>
#include <tables/Tables/SetupNewTab.h>
#include <tables/Tables/TableCopy.h>
#include <tables/Tables/TableDesc.h>
#include <tables/Tables/TableIter.h>
#include <tables/Tables/TableParse.h>
#include <tables/Tables/TableRecord.h>
#include <tables/Tables/TableRow.h>
#include <tables/Tables/TableVector.h>

#include "MathUtils.h"
#include "STAttr.h"
#include "STLineFinder.h"
#include "STPolCircular.h"
#include "STPolLinear.h"
#include "STPolStokes.h"
#include "STUpgrade.h"
#include "Scantable.h"

#define debug 1

using namespace casa;

namespace asap {

std::map<std::string, STPol::STPolFactory *> Scantable::factories_;

void Scantable::initFactories() {
  if ( factories_.empty() ) {
    Scantable::factories_["linear"] = &STPolLinear::myFactory;
    Scantable::factories_["circular"] = &STPolCircular::myFactory;
    Scantable::factories_["stokes"] = &STPolStokes::myFactory;
  }
}

Scantable::Scantable(Table::TableType ttype) :
  type_(ttype)
{
  initFactories();
  setupMainTable();
  freqTable_ = STFrequencies(*this);
  table_.rwKeywordSet().defineTable("FREQUENCIES", freqTable_.table());
  weatherTable_ = STWeather(*this);
  table_.rwKeywordSet().defineTable("WEATHER", weatherTable_.table());
  focusTable_ = STFocus(*this);
  table_.rwKeywordSet().defineTable("FOCUS", focusTable_.table());
  tcalTable_ = STTcal(*this);
  table_.rwKeywordSet().defineTable("TCAL", tcalTable_.table());
  moleculeTable_ = STMolecules(*this);
  table_.rwKeywordSet().defineTable("MOLECULES", moleculeTable_.table());
  historyTable_ = STHistory(*this);
  table_.rwKeywordSet().defineTable("HISTORY", historyTable_.table());
  fitTable_ = STFit(*this);
  table_.rwKeywordSet().defineTable("FIT", fitTable_.table());
  table_.tableInfo().setType( "Scantable" ) ;
  originalTable_ = table_;
  attach();
}

Scantable::Scantable(const std::string& name, Table::TableType ttype) :
  type_(ttype)
{
  initFactories();

  Table tab(name, Table::Update);
  uInt version = tab.keywordSet().asuInt("VERSION");
  if (version != version_) {
      STUpgrade upgrader(version_);
      LogIO os( LogOrigin( "Scantable" ) ) ;
      os << LogIO::WARN
         << name << " data format version " << version 
         << " is deprecated" << endl 
         << "Running upgrade."<< endl  
         << LogIO::POST ;  
      std::string outname = upgrader.upgrade(name);
      if ( outname != name ) {
        os << LogIO::WARN
           << "Data will be loaded from " << outname << " instead of " 
           << name << LogIO::POST ;
        tab = Table(outname, Table::Update ) ;
      }
  }
  if ( type_ == Table::Memory ) {
    table_ = tab.copyToMemoryTable(generateName());
  } else {
    table_ = tab;
  }
  table_.tableInfo().setType( "Scantable" ) ;

  attachSubtables();
  originalTable_ = table_;
  attach();
}
/*
Scantable::Scantable(const std::string& name, Table::TableType ttype) :
  type_(ttype)
{
  initFactories();
  Table tab(name, Table::Update);
  uInt version = tab.keywordSet().asuInt("VERSION");
  if (version != version_) {
    throw(AipsError("Unsupported version of ASAP file."));
  }
  if ( type_ == Table::Memory ) {
    table_ = tab.copyToMemoryTable(generateName());
  } else {
    table_ = tab;
  }

  attachSubtables();
  originalTable_ = table_;
  attach();
}
*/

Scantable::Scantable( const Scantable& other, bool clear ):
  Logger()
{
  // with or without data
  String newname = String(generateName());
  type_ = other.table_.tableType();
  if ( other.table_.tableType() == Table::Memory ) {
      if ( clear ) {
        table_ = TableCopy::makeEmptyMemoryTable(newname,
                                                 other.table_, True);
      } else
        table_ = other.table_.copyToMemoryTable(newname);
  } else {
      other.table_.deepCopy(newname, Table::New, False,
                            other.table_.endianFormat(),
                            Bool(clear));
      table_ = Table(newname, Table::Update);
      table_.markForDelete();
  }
  table_.tableInfo().setType( "Scantable" ) ;
  /// @todo reindex SCANNO, recompute nbeam, nif, npol
  if ( clear ) copySubtables(other);
  attachSubtables();
  originalTable_ = table_;
  attach();
}

void Scantable::copySubtables(const Scantable& other) {
  Table t = table_.rwKeywordSet().asTable("FREQUENCIES");
  TableCopy::copyRows(t, other.freqTable_.table());
  t = table_.rwKeywordSet().asTable("FOCUS");
  TableCopy::copyRows(t, other.focusTable_.table());
  t = table_.rwKeywordSet().asTable("WEATHER");
  TableCopy::copyRows(t, other.weatherTable_.table());
  t = table_.rwKeywordSet().asTable("TCAL");
  TableCopy::copyRows(t, other.tcalTable_.table());
  t = table_.rwKeywordSet().asTable("MOLECULES");
  TableCopy::copyRows(t, other.moleculeTable_.table());
  t = table_.rwKeywordSet().asTable("HISTORY");
  TableCopy::copyRows(t, other.historyTable_.table());
  t = table_.rwKeywordSet().asTable("FIT");
  TableCopy::copyRows(t, other.fitTable_.table());
}

void Scantable::attachSubtables()
{
  freqTable_ = STFrequencies(table_);
  focusTable_ = STFocus(table_);
  weatherTable_ = STWeather(table_);
  tcalTable_ = STTcal(table_);
  moleculeTable_ = STMolecules(table_);
  historyTable_ = STHistory(table_);
  fitTable_ = STFit(table_);
}

Scantable::~Scantable()
{
}

void Scantable::setupMainTable()
{
  TableDesc td("", "1", TableDesc::Scratch);
  td.comment() = "An ASAP Scantable";
  td.rwKeywordSet().define("VERSION", uInt(version_));

  // n Cycles
  td.addColumn(ScalarColumnDesc<uInt>("SCANNO"));
  // new index every nBeam x nIF x nPol
  td.addColumn(ScalarColumnDesc<uInt>("CYCLENO"));

  td.addColumn(ScalarColumnDesc<uInt>("BEAMNO"));
  td.addColumn(ScalarColumnDesc<uInt>("IFNO"));
  // linear, circular, stokes
  td.rwKeywordSet().define("POLTYPE", String("linear"));
  td.addColumn(ScalarColumnDesc<uInt>("POLNO"));

  td.addColumn(ScalarColumnDesc<uInt>("FREQ_ID"));
  td.addColumn(ScalarColumnDesc<uInt>("MOLECULE_ID"));

  ScalarColumnDesc<Int> refbeamnoColumn("REFBEAMNO");
  refbeamnoColumn.setDefault(Int(-1));
  td.addColumn(refbeamnoColumn);

  ScalarColumnDesc<uInt> flagrowColumn("FLAGROW");
  flagrowColumn.setDefault(uInt(0));
  td.addColumn(flagrowColumn);

  td.addColumn(ScalarColumnDesc<Double>("TIME"));
  TableMeasRefDesc measRef(MEpoch::UTC); // UTC as default
  TableMeasValueDesc measVal(td, "TIME");
  TableMeasDesc<MEpoch> mepochCol(measVal, measRef);
  mepochCol.write(td);

  td.addColumn(ScalarColumnDesc<Double>("INTERVAL"));

  td.addColumn(ScalarColumnDesc<String>("SRCNAME"));
  // Type of source (on=0, off=1, other=-1)
  ScalarColumnDesc<Int> stypeColumn("SRCTYPE");
  stypeColumn.setDefault(Int(-1));
  td.addColumn(stypeColumn);
  td.addColumn(ScalarColumnDesc<String>("FIELDNAME"));

  //The actual Data Vectors
  td.addColumn(ArrayColumnDesc<Float>("SPECTRA"));
  td.addColumn(ArrayColumnDesc<uChar>("FLAGTRA"));
  td.addColumn(ArrayColumnDesc<Float>("TSYS"));

  td.addColumn(ArrayColumnDesc<Double>("DIRECTION",
                                       IPosition(1,2),
                                       ColumnDesc::Direct));
  TableMeasRefDesc mdirRef(MDirection::J2000); // default
  TableMeasValueDesc tmvdMDir(td, "DIRECTION");
  // the TableMeasDesc gives the column a type
  TableMeasDesc<MDirection> mdirCol(tmvdMDir, mdirRef);
  // a uder set table type e.g. GALCTIC, B1950 ...
  td.rwKeywordSet().define("DIRECTIONREF", String("J2000"));
  // writing create the measure column
  mdirCol.write(td);
  td.addColumn(ScalarColumnDesc<Float>("AZIMUTH"));
  td.addColumn(ScalarColumnDesc<Float>("ELEVATION"));
  td.addColumn(ScalarColumnDesc<Float>("OPACITY"));

  td.addColumn(ScalarColumnDesc<uInt>("TCAL_ID"));
  ScalarColumnDesc<Int> fitColumn("FIT_ID");
  fitColumn.setDefault(Int(-1));
  td.addColumn(fitColumn);

  td.addColumn(ScalarColumnDesc<uInt>("FOCUS_ID"));
  td.addColumn(ScalarColumnDesc<uInt>("WEATHER_ID"));

  // columns which just get dragged along, as they aren't used in asap
  td.addColumn(ScalarColumnDesc<Double>("SRCVELOCITY"));
  td.addColumn(ArrayColumnDesc<Double>("SRCPROPERMOTION"));
  td.addColumn(ArrayColumnDesc<Double>("SRCDIRECTION"));
  td.addColumn(ArrayColumnDesc<Double>("SCANRATE"));

  td.rwKeywordSet().define("OBSMODE", String(""));

  // Now create Table SetUp from the description.
  SetupNewTable aNewTab(generateName(), td, Table::Scratch);
  table_ = Table(aNewTab, type_, 0);
  originalTable_ = table_;
}

void Scantable::attach()
{
  timeCol_.attach(table_, "TIME");
  srcnCol_.attach(table_, "SRCNAME");
  srctCol_.attach(table_, "SRCTYPE");
  specCol_.attach(table_, "SPECTRA");
  flagsCol_.attach(table_, "FLAGTRA");
  tsysCol_.attach(table_, "TSYS");
  cycleCol_.attach(table_,"CYCLENO");
  scanCol_.attach(table_, "SCANNO");
  beamCol_.attach(table_, "BEAMNO");
  ifCol_.attach(table_, "IFNO");
  polCol_.attach(table_, "POLNO");
  integrCol_.attach(table_, "INTERVAL");
  azCol_.attach(table_, "AZIMUTH");
  elCol_.attach(table_, "ELEVATION");
  dirCol_.attach(table_, "DIRECTION");
  fldnCol_.attach(table_, "FIELDNAME");
  rbeamCol_.attach(table_, "REFBEAMNO");

  mweatheridCol_.attach(table_,"WEATHER_ID");
  mfitidCol_.attach(table_,"FIT_ID");
  mfreqidCol_.attach(table_, "FREQ_ID");
  mtcalidCol_.attach(table_, "TCAL_ID");
  mfocusidCol_.attach(table_, "FOCUS_ID");
  mmolidCol_.attach(table_, "MOLECULE_ID");

  //Add auxiliary column for row-based flagging (CAS-1433 Wataru Kawasaki)
  attachAuxColumnDef(flagrowCol_, "FLAGROW", 0);

}

template<class T, class T2>
void Scantable::attachAuxColumnDef(ScalarColumn<T>& col,
                                   const String& colName,
                                   const T2& defValue)
{
  try {
    col.attach(table_, colName);
  } catch (TableError& err) {
    String errMesg = err.getMesg();
    if (errMesg == "Table column " + colName + " is unknown") {
      table_.addColumn(ScalarColumnDesc<T>(colName));
      col.attach(table_, colName);
      col.fillColumn(static_cast<T>(defValue));
    } else {
      throw;
    }
  } catch (...) {
    throw;
  }
}

template<class T, class T2>
void Scantable::attachAuxColumnDef(ArrayColumn<T>& col,
                                   const String& colName,
                                   const Array<T2>& defValue)
{
  try {
    col.attach(table_, colName);
  } catch (TableError& err) {
    String errMesg = err.getMesg();
    if (errMesg == "Table column " + colName + " is unknown") {
      table_.addColumn(ArrayColumnDesc<T>(colName));
      col.attach(table_, colName);

      int size = 0;
      ArrayIterator<T2>& it = defValue.begin();
      while (it != defValue.end()) {
        ++size;
        ++it;
      }
      IPosition ip(1, size);
      Array<T>& arr(ip);
      for (int i = 0; i < size; ++i)
        arr[i] = static_cast<T>(defValue[i]);

      col.fillColumn(arr);
    } else {
      throw;
    }
  } catch (...) {
    throw;
  }
}

void Scantable::setHeader(const STHeader& sdh)
{
  table_.rwKeywordSet().define("nIF", sdh.nif);
  table_.rwKeywordSet().define("nBeam", sdh.nbeam);
  table_.rwKeywordSet().define("nPol", sdh.npol);
  table_.rwKeywordSet().define("nChan", sdh.nchan);
  table_.rwKeywordSet().define("Observer", sdh.observer);
  table_.rwKeywordSet().define("Project", sdh.project);
  table_.rwKeywordSet().define("Obstype", sdh.obstype);
  table_.rwKeywordSet().define("AntennaName", sdh.antennaname);
  table_.rwKeywordSet().define("AntennaPosition", sdh.antennaposition);
  table_.rwKeywordSet().define("Equinox", sdh.equinox);
  table_.rwKeywordSet().define("FreqRefFrame", sdh.freqref);
  table_.rwKeywordSet().define("FreqRefVal", sdh.reffreq);
  table_.rwKeywordSet().define("Bandwidth", sdh.bandwidth);
  table_.rwKeywordSet().define("UTC", sdh.utc);
  table_.rwKeywordSet().define("FluxUnit", sdh.fluxunit);
  table_.rwKeywordSet().define("Epoch", sdh.epoch);
  table_.rwKeywordSet().define("POLTYPE", sdh.poltype);
}

STHeader Scantable::getHeader() const
{
  STHeader sdh;
  table_.keywordSet().get("nBeam",sdh.nbeam);
  table_.keywordSet().get("nIF",sdh.nif);
  table_.keywordSet().get("nPol",sdh.npol);
  table_.keywordSet().get("nChan",sdh.nchan);
  table_.keywordSet().get("Observer", sdh.observer);
  table_.keywordSet().get("Project", sdh.project);
  table_.keywordSet().get("Obstype", sdh.obstype);
  table_.keywordSet().get("AntennaName", sdh.antennaname);
  table_.keywordSet().get("AntennaPosition", sdh.antennaposition);
  table_.keywordSet().get("Equinox", sdh.equinox);
  table_.keywordSet().get("FreqRefFrame", sdh.freqref);
  table_.keywordSet().get("FreqRefVal", sdh.reffreq);
  table_.keywordSet().get("Bandwidth", sdh.bandwidth);
  table_.keywordSet().get("UTC", sdh.utc);
  table_.keywordSet().get("FluxUnit", sdh.fluxunit);
  table_.keywordSet().get("Epoch", sdh.epoch);
  table_.keywordSet().get("POLTYPE", sdh.poltype);
  return sdh;
}

void Scantable::setSourceType( int stype )
{
  if ( stype < 0 || stype > 1 )
    throw(AipsError("Illegal sourcetype."));
  TableVector<Int> tabvec(table_, "SRCTYPE");
  tabvec = Int(stype);
}

bool Scantable::conformant( const Scantable& other )
{
  return this->getHeader().conformant(other.getHeader());
}



std::string Scantable::formatSec(Double x) const
{
  Double xcop = x;
  MVTime mvt(xcop/24./3600.);  // make days

  if (x < 59.95)
    return  String("      ") + mvt.string(MVTime::TIME_CLEAN_NO_HM, 7)+"s";
  else if (x < 3599.95)
    return String("   ") + mvt.string(MVTime::TIME_CLEAN_NO_H,7)+" ";
  else {
    ostringstream oss;
    oss << setw(2) << std::right << setprecision(1) << mvt.hour();
    oss << ":" << mvt.string(MVTime::TIME_CLEAN_NO_H,7) << " ";
    return String(oss);
  }
};

std::string Scantable::formatDirection(const MDirection& md) const
{
  Vector<Double> t = md.getAngle(Unit(String("rad"))).getValue();
  Int prec = 7;

  MVAngle mvLon(t[0]);
  String sLon = mvLon.string(MVAngle::TIME,prec);
  uInt tp = md.getRef().getType();
  if (tp == MDirection::GALACTIC ||
      tp == MDirection::SUPERGAL ) {
    sLon = mvLon(0.0).string(MVAngle::ANGLE_CLEAN,prec);
  }
  MVAngle mvLat(t[1]);
  String sLat = mvLat.string(MVAngle::ANGLE+MVAngle::DIG2,prec);
  return sLon + String(" ") + sLat;
}


std::string Scantable::getFluxUnit() const
{
  return table_.keywordSet().asString("FluxUnit");
}

void Scantable::setFluxUnit(const std::string& unit)
{
  String tmp(unit);
  Unit tU(tmp);
  if (tU==Unit("K") || tU==Unit("Jy")) {
     table_.rwKeywordSet().define(String("FluxUnit"), tmp);
  } else {
     throw AipsError("Illegal unit - must be compatible with Jy or K");
  }
}

void Scantable::setInstrument(const std::string& name)
{
  bool throwIt = true;
  // create an Instrument to see if this is valid
  STAttr::convertInstrument(name, throwIt);
  String nameU(name);
  nameU.upcase();
  table_.rwKeywordSet().define(String("AntennaName"), nameU);
}

void Scantable::setFeedType(const std::string& feedtype)
{
  if ( Scantable::factories_.find(feedtype) ==  Scantable::factories_.end() ) {
    std::string msg = "Illegal feed type "+ feedtype;
    throw(casa::AipsError(msg));
  }
  table_.rwKeywordSet().define(String("POLTYPE"), feedtype);
}

MPosition Scantable::getAntennaPosition() const
{
  Vector<Double> antpos;
  table_.keywordSet().get("AntennaPosition", antpos);
  MVPosition mvpos(antpos(0),antpos(1),antpos(2));
  return MPosition(mvpos);
}

void Scantable::makePersistent(const std::string& filename)
{
  String inname(filename);
  Path path(inname);
  /// @todo reindex SCANNO, recompute nbeam, nif, npol
  inname = path.expandedName();
  // 2011/03/04 TN
  // We can comment out this workaround since the essential bug is 
  // fixed in casacore (r20889 in google code).
  table_.deepCopy(inname, Table::New);
//   // WORKAROUND !!! for Table bug
//   // Remove when fixed in casacore
//   if ( table_.tableType() == Table::Memory  && !selector_.empty() ) {
//     Table tab = table_.copyToMemoryTable(generateName());
//     tab.deepCopy(inname, Table::New);
//     tab.markForDelete();
//
//   } else {
//     table_.deepCopy(inname, Table::New);
//   }
}

int Scantable::nbeam( int scanno ) const
{
  if ( scanno < 0 ) {
    Int n;
    table_.keywordSet().get("nBeam",n);
    return int(n);
  } else {
    // take the first POLNO,IFNO,CYCLENO as nbeam shouldn't vary with these
    Table t = table_(table_.col("SCANNO") == scanno);
    ROTableRow row(t);
    const TableRecord& rec = row.get(0);
    Table subt = t( t.col("IFNO") == Int(rec.asuInt("IFNO"))
                    && t.col("POLNO") == Int(rec.asuInt("POLNO"))
                    && t.col("CYCLENO") == Int(rec.asuInt("CYCLENO")) );
    ROTableVector<uInt> v(subt, "BEAMNO");
    return int(v.nelements());
  }
  return 0;
}

int Scantable::nif( int scanno ) const
{
  if ( scanno < 0 ) {
    Int n;
    table_.keywordSet().get("nIF",n);
    return int(n);
  } else {
    // take the first POLNO,BEAMNO,CYCLENO as nbeam shouldn't vary with these
    Table t = table_(table_.col("SCANNO") == scanno);
    ROTableRow row(t);
    const TableRecord& rec = row.get(0);
    Table subt = t( t.col("BEAMNO") == Int(rec.asuInt("BEAMNO"))
                    && t.col("POLNO") == Int(rec.asuInt("POLNO"))
                    && t.col("CYCLENO") == Int(rec.asuInt("CYCLENO")) );
    if ( subt.nrow() == 0 ) return 0;
    ROTableVector<uInt> v(subt, "IFNO");
    return int(v.nelements());
  }
  return 0;
}

int Scantable::npol( int scanno ) const
{
  if ( scanno < 0 ) {
    Int n;
    table_.keywordSet().get("nPol",n);
    return n;
  } else {
    // take the first POLNO,IFNO,CYCLENO as nbeam shouldn't vary with these
    Table t = table_(table_.col("SCANNO") == scanno);
    ROTableRow row(t);
    const TableRecord& rec = row.get(0);
    Table subt = t( t.col("BEAMNO") == Int(rec.asuInt("BEAMNO"))
                    && t.col("IFNO") == Int(rec.asuInt("IFNO"))
                    && t.col("CYCLENO") == Int(rec.asuInt("CYCLENO")) );
    if ( subt.nrow() == 0 ) return 0;
    ROTableVector<uInt> v(subt, "POLNO");
    return int(v.nelements());
  }
  return 0;
}

int Scantable::ncycle( int scanno ) const
{
  if ( scanno < 0 ) {
    Block<String> cols(2);
    cols[0] = "SCANNO";
    cols[1] = "CYCLENO";
    TableIterator it(table_, cols);
    int n = 0;
    while ( !it.pastEnd() ) {
      ++n;
      ++it;
    }
    return n;
  } else {
    Table t = table_(table_.col("SCANNO") == scanno);
    ROTableRow row(t);
    const TableRecord& rec = row.get(0);
    Table subt = t( t.col("BEAMNO") == Int(rec.asuInt("BEAMNO"))
                    && t.col("POLNO") == Int(rec.asuInt("POLNO"))
                    && t.col("IFNO") == Int(rec.asuInt("IFNO")) );
    if ( subt.nrow() == 0 ) return 0;
    return int(subt.nrow());
  }
  return 0;
}


int Scantable::nrow( int scanno ) const
{
  return int(table_.nrow());
}

int Scantable::nchan( int ifno ) const
{
  if ( ifno < 0 ) {
    Int n;
    table_.keywordSet().get("nChan",n);
    return int(n);
  } else {
    // take the first SCANNO,POLNO,BEAMNO,CYCLENO as nbeam shouldn't
    // vary with these
    Table t = table_(table_.col("IFNO") == ifno, 1);
    if ( t.nrow() == 0 ) return 0;
    ROArrayColumn<Float> v(t, "SPECTRA");
    return v.shape(0)(0);
  }
  return 0;
}

int Scantable::nscan() const {
  Vector<uInt> scannos(scanCol_.getColumn());
  uInt nout = genSort( scannos, Sort::Ascending,
                       Sort::QuickSort|Sort::NoDuplicates );
  return int(nout);
}

int Scantable::getChannels(int whichrow) const
{
  return specCol_.shape(whichrow)(0);
}

int Scantable::getBeam(int whichrow) const
{
  return beamCol_(whichrow);
}

std::vector<uint> Scantable::getNumbers(const ScalarColumn<uInt>& col) const
{
  Vector<uInt> nos(col.getColumn());
  uInt n = genSort( nos, Sort::Ascending, Sort::QuickSort|Sort::NoDuplicates );
  nos.resize(n, True);
  std::vector<uint> stlout;
  nos.tovector(stlout);
  return stlout;
}

int Scantable::getIF(int whichrow) const
{
  return ifCol_(whichrow);
}

int Scantable::getPol(int whichrow) const
{
  return polCol_(whichrow);
}

std::string Scantable::formatTime(const MEpoch& me, bool showdate) const
{
  return formatTime(me, showdate, 0);
}

std::string Scantable::formatTime(const MEpoch& me, bool showdate, uInt prec) const
{
  MVTime mvt(me.getValue());
  if (showdate)
    //mvt.setFormat(MVTime::YMD);
    mvt.setFormat(MVTime::YMD, prec);
  else
    //mvt.setFormat(MVTime::TIME);
    mvt.setFormat(MVTime::TIME, prec);
  ostringstream oss;
  oss << mvt;
  return String(oss);
}

void Scantable::calculateAZEL()
{
  MPosition mp = getAntennaPosition();
  MEpoch::ROScalarColumn timeCol(table_, "TIME");
  ostringstream oss;
  oss << "Computed azimuth/elevation using " << endl
      << mp << endl;
  for (Int i=0; i<nrow(); ++i) {
    MEpoch me = timeCol(i);
    MDirection md = getDirection(i);
    oss  << " Time: " << formatTime(me,False) << " Direction: " << formatDirection(md)
         << endl << "     => ";
    MeasFrame frame(mp, me);
    Vector<Double> azel =
        MDirection::Convert(md, MDirection::Ref(MDirection::AZEL,
                                                frame)
                            )().getAngle("rad").getValue();
    azCol_.put(i,Float(azel[0]));
    elCol_.put(i,Float(azel[1]));
    oss << "azel: " << azel[0]/C::pi*180.0 << " "
        << azel[1]/C::pi*180.0 << " (deg)" << endl;
  }
  pushLog(String(oss));
}

void Scantable::clip(const Float uthres, const Float dthres, bool clipoutside, bool unflag)
{
  for (uInt i=0; i<table_.nrow(); ++i) {
    Vector<uChar> flgs = flagsCol_(i);
    srchChannelsToClip(i, uthres, dthres, clipoutside, unflag, flgs);
    flagsCol_.put(i, flgs);
  }
}

std::vector<bool> Scantable::getClipMask(int whichrow, const Float uthres, const Float dthres, bool clipoutside, bool unflag)
{
  Vector<uChar> flags;
  flagsCol_.get(uInt(whichrow), flags);
  srchChannelsToClip(uInt(whichrow), uthres, dthres, clipoutside, unflag, flags);
  Vector<Bool> bflag(flags.shape());
  convertArray(bflag, flags);
  //bflag = !bflag;

  std::vector<bool> mask;
  bflag.tovector(mask);
  return mask;
}

void Scantable::srchChannelsToClip(uInt whichrow, const Float uthres, const Float dthres, bool clipoutside, bool unflag,
                                   Vector<uChar> flgs)
{
    Vector<Float> spcs = specCol_(whichrow);
    uInt nchannel = spcs.nelements();
    if (spcs.nelements() != nchannel) {
      throw(AipsError("Data has incorrect number of channels"));
    }
    uChar userflag = 1 << 7;
    if (unflag) {
      userflag = 0 << 7;
    }
    if (clipoutside) {
      for (uInt j = 0; j < nchannel; ++j) {
        Float spc = spcs(j);
        if ((spc >= uthres) || (spc <= dthres)) {
          flgs(j) = userflag;
        }
      }
    } else {
      for (uInt j = 0; j < nchannel; ++j) {
        Float spc = spcs(j);
        if ((spc < uthres) && (spc > dthres)) {
          flgs(j) = userflag;
        }
      }
    }
}


void Scantable::flag( int whichrow, const std::vector<bool>& msk, bool unflag ) {
  std::vector<bool>::const_iterator it;
  uInt ntrue = 0;
  if (whichrow >= int(table_.nrow()) ) {
    throw(AipsError("Invalid row number"));
  }
  for (it = msk.begin(); it != msk.end(); ++it) {
    if ( *it ) {
      ntrue++;
    }
  }
  //if ( selector_.empty()  && (msk.size() == 0 || msk.size() == ntrue) )
  if ( whichrow == -1 && !unflag && selector_.empty() && (msk.size() == 0 || msk.size() == ntrue) )
    throw(AipsError("Trying to flag whole scantable."));
  uChar userflag = 1 << 7;
  if ( unflag ) {
    userflag = 0 << 7;
  }
  if (whichrow > -1 ) {
    applyChanFlag(uInt(whichrow), msk, userflag);
  } else {
    for ( uInt i=0; i<table_.nrow(); ++i) {
      applyChanFlag(i, msk, userflag);
    }
  }
}

void Scantable::applyChanFlag( uInt whichrow, const std::vector<bool>& msk, uChar flagval )
{
  if (whichrow >= table_.nrow() ) {
    throw( casa::indexError<int>( whichrow, "asap::Scantable::applyChanFlag: Invalid row number" ) );
  }
  Vector<uChar> flgs = flagsCol_(whichrow);
  if ( msk.size() == 0 ) {
    flgs = flagval;
    flagsCol_.put(whichrow, flgs);
    return;
  }
  if ( int(msk.size()) != nchan( getIF(whichrow) ) ) {
    throw(AipsError("Mask has incorrect number of channels."));
  }
  if ( flgs.nelements() != msk.size() ) {
    throw(AipsError("Mask has incorrect number of channels."
                    " Probably varying with IF. Please flag per IF"));
  }
  std::vector<bool>::const_iterator it;
  uInt j = 0;
  for (it = msk.begin(); it != msk.end(); ++it) {
    if ( *it ) {
      flgs(j) = flagval;
    }
    ++j;
  }
  flagsCol_.put(whichrow, flgs);
}

void Scantable::flagRow(const std::vector<uInt>& rows, bool unflag)
{
  if ( selector_.empty() && (rows.size() == table_.nrow()) )
    throw(AipsError("Trying to flag whole scantable."));

  uInt rowflag = (unflag ? 0 : 1);
  std::vector<uInt>::const_iterator it;
  for (it = rows.begin(); it != rows.end(); ++it)
    flagrowCol_.put(*it, rowflag);
}

std::vector<bool> Scantable::getMask(int whichrow) const
{
  Vector<uChar> flags;
  flagsCol_.get(uInt(whichrow), flags);
  Vector<Bool> bflag(flags.shape());
  convertArray(bflag, flags);
  bflag = !bflag;
  std::vector<bool> mask;
  bflag.tovector(mask);
  return mask;
}

std::vector<float> Scantable::getSpectrum( int whichrow,
                                           const std::string& poltype ) const
{
  String ptype = poltype;
  if (poltype == "" ) ptype = getPolType();
  if ( whichrow  < 0 || whichrow >= nrow() )
    throw(AipsError("Illegal row number."));
  std::vector<float> out;
  Vector<Float> arr;
  uInt requestedpol = polCol_(whichrow);
  String basetype = getPolType();
  if ( ptype == basetype ) {
    specCol_.get(whichrow, arr);
  } else {
    CountedPtr<STPol> stpol(STPol::getPolClass(Scantable::factories_,
                                               basetype));
    uInt row = uInt(whichrow);
    stpol->setSpectra(getPolMatrix(row));
    Float fang,fhand;
    fang = focusTable_.getTotalAngle(mfocusidCol_(row));
    fhand = focusTable_.getFeedHand(mfocusidCol_(row));
    stpol->setPhaseCorrections(fang, fhand);
    arr = stpol->getSpectrum(requestedpol, ptype);
  }
  if ( arr.nelements() == 0 )
    pushLog("Not enough polarisations present to do the conversion.");
  arr.tovector(out);
  return out;
}

void Scantable::setSpectrum( const std::vector<float>& spec,
                                   int whichrow )
{
  Vector<Float> spectrum(spec);
  Vector<Float> arr;
  specCol_.get(whichrow, arr);
  if ( spectrum.nelements() != arr.nelements() )
    throw AipsError("The spectrum has incorrect number of channels.");
  specCol_.put(whichrow, spectrum);
}


String Scantable::generateName()
{
  return (File::newUniqueName("./","temp")).baseName();
}

const casa::Table& Scantable::table( ) const
{
  return table_;
}

casa::Table& Scantable::table( )
{
  return table_;
}

std::string Scantable::getPolType() const
{
  return table_.keywordSet().asString("POLTYPE");
}

void Scantable::unsetSelection()
{
  table_ = originalTable_;
  attach();
  selector_.reset();
}

void Scantable::setSelection( const STSelector& selection )
{
  Table tab = const_cast<STSelector&>(selection).apply(originalTable_);
  if ( tab.nrow() == 0 ) {
    throw(AipsError("Selection contains no data. Not applying it."));
  }
  table_ = tab;
  attach();
//   tab.rwKeywordSet().define("nBeam",(Int)(getBeamNos().size())) ;
//   vector<uint> selectedIFs = getIFNos() ;
//   Int newnIF = selectedIFs.size() ;
//   tab.rwKeywordSet().define("nIF",newnIF) ;
//   if ( newnIF != 0 ) {
//     Int newnChan = 0 ;
//     for ( Int i = 0 ; i < newnIF ; i++ ) {
//       Int nChan = nchan( selectedIFs[i] ) ;
//       if ( newnChan > nChan )
//         newnChan = nChan ;
//     }
//     tab.rwKeywordSet().define("nChan",newnChan) ;
//   }
//   tab.rwKeywordSet().define("nPol",(Int)(getPolNos().size())) ;
  selector_ = selection;
}


std::string Scantable::headerSummary()
{
  // Format header info
//   STHeader sdh;
//   sdh = getHeader();
//   sdh.print();
  ostringstream oss;
  oss.flags(std::ios_base::left);
  String tmp;
  // Project
  table_.keywordSet().get("Project", tmp);
  oss << setw(15) << "Project:" << tmp << endl;
  // Observation date
  oss << setw(15) << "Obs Date:" << getTime(-1,true) << endl;
  // Observer
  oss << setw(15) << "Observer:"
      << table_.keywordSet().asString("Observer") << endl;
  // Antenna Name
  table_.keywordSet().get("AntennaName", tmp);
  oss << setw(15) << "Antenna Name:" << tmp << endl;
  // Obs type
  table_.keywordSet().get("Obstype", tmp);
  // Records (nrow)
  oss << setw(15) << "Data Records:" << table_.nrow() << " rows" << endl;
  oss << setw(15) << "Obs. Type:" << tmp << endl;
  // Beams, IFs, Polarizations, and Channels
  oss << setw(15) << "Beams:" << setw(4) << nbeam() << endl
      << setw(15) << "IFs:" << setw(4) << nif() << endl
      << setw(15) << "Polarisations:" << setw(4) << npol()
      << "(" << getPolType() << ")" << endl
      << setw(15) << "Channels:" << nchan() << endl;
  // Flux unit
  table_.keywordSet().get("FluxUnit", tmp);
  oss << setw(15) << "Flux Unit:" << tmp << endl;
  // Abscissa Unit
  oss << setw(15) << "Abscissa:" << getAbcissaLabel(0) << endl;
  // Selection
  oss << selector_.print() << endl;

  return String(oss);
}

void Scantable::summary( const std::string& filename )
{
  ostringstream oss;
  ofstream ofs;
  LogIO ols(LogOrigin("Scantable", "summary", WHERE));

  if (filename != "")
    ofs.open( filename.c_str(),  ios::out );

  oss << endl;
  oss << asap::SEPERATOR << endl;
  oss << " Scan Table Summary" << endl;
  oss << asap::SEPERATOR << endl;

  // Format header info
  oss << headerSummary();
  oss << endl;

  if (table_.nrow() <= 0){
    oss << asap::SEPERATOR << endl;
    oss << "The MAIN table is empty: there are no data!!!" << endl;
    oss << asap::SEPERATOR << endl;

    ols << String(oss) << LogIO::POST;
    if (ofs) {
      ofs << String(oss) << flush;
      ofs.close();
    }
    return;
  }



  // main table
  String dirtype = "Position ("
                  + getDirectionRefString()
                  + ")";
  oss.flags(std::ios_base::left);
  oss << setw(5) << "Scan" 
      << setw(15) << "Source"
      << setw(35) << "Time range"
      << setw(2) << "" << setw(7) << "Int[s]"
      << setw(7) << "Record"
      << setw(8) << "SrcType"
      << setw(8) << "FreqIDs"
      << setw(7) << "MolIDs" << endl;
  oss << setw(7)<< "" << setw(6) << "Beam"
      << setw(23) << dirtype << endl;

  oss << asap::SEPERATOR << endl;

  // Flush summary and clear up the string
  ols << String(oss) << LogIO::POST;
  if (ofs) ofs << String(oss) << flush;
  oss.str("");
  oss.clear();


  // Get Freq_ID map
  ROScalarColumn<uInt> ftabIds(frequencies().table(), "ID");
  Int nfid = ftabIds.nrow();
  if (nfid <= 0){
    oss << "FREQUENCIES subtable is empty: there are no data!!!" << endl;
    oss << asap::SEPERATOR << endl;

    ols << String(oss) << LogIO::POST;
    if (ofs) {
      ofs << String(oss) << flush;
      ofs.close();
    }
    return;
  }
  // Storages of overall IFNO, POLNO, and nchan per FREQ_ID
  // the orders are identical to ID in FREQ subtable
  Block< Vector<uInt> > ifNos(nfid), polNos(nfid);
  Vector<Int> fIdchans(nfid,-1);
  map<uInt, Int> fidMap;  // (FREQ_ID, row # in FREQ subtable) pair
  for (Int i=0; i < nfid; i++){
   // fidMap[freqId] returns row number in FREQ subtable
   fidMap.insert(pair<uInt, Int>(ftabIds(i),i));
   ifNos[i] = Vector<uInt>();
   polNos[i] = Vector<uInt>();
  }

  TableIterator iter(table_, "SCANNO");

  // Vars for keeping track of time, freqids, molIds in a SCANNO
  Vector<uInt> freqids;
  Vector<uInt> molids;
  Vector<uInt> beamids(1,0);
  Vector<MDirection> beamDirs;
  Vector<Int> stypeids(1,0);
  Vector<String> stypestrs;
  Int nfreq(1);
  Int nmol(1);
  uInt nbeam(1);
  uInt nstype(1);

  Double btime(0.0), etime(0.0);
  Double meanIntTim(0.0);

  uInt currFreqId(0), ftabRow(0);
  Int iflen(0), pollen(0);

  while (!iter.pastEnd()) {
    Table subt = iter.table();
    uInt snrow = subt.nrow();
    ROTableRow row(subt);
    const TableRecord& rec = row.get(0);

    // relevant columns
    ROScalarColumn<Double> mjdCol(subt,"TIME");
    ROScalarColumn<Double> intervalCol(subt,"INTERVAL");
    MDirection::ROScalarColumn dirCol(subt,"DIRECTION");

    ScalarColumn<uInt> freqIdCol(subt,"FREQ_ID");
    ScalarColumn<uInt> molIdCol(subt,"MOLECULE_ID");
    ROScalarColumn<uInt> beamCol(subt,"BEAMNO");
    ROScalarColumn<Int> stypeCol(subt,"SRCTYPE");

    ROScalarColumn<uInt> ifNoCol(subt,"IFNO");
    ROScalarColumn<uInt> polNoCol(subt,"POLNO");


    // Times
    meanIntTim = sum(intervalCol.getColumn()) / (double) snrow;
    minMax(btime, etime, mjdCol.getColumn());
    etime += meanIntTim/C::day;

    // MOLECULE_ID and FREQ_ID
    molids = getNumbers(molIdCol);
    molids.shape(nmol);

    freqids = getNumbers(freqIdCol);
    freqids.shape(nfreq);

    // Add first beamid, and srcNames
    beamids.resize(1,False);
    beamDirs.resize(1,False);
    beamids(0)=beamCol(0);
    beamDirs(0)=dirCol(0);
    nbeam = 1;

    stypeids.resize(1,False);
    stypeids(0)=stypeCol(0);
    nstype = 1;

    // Global listings of nchan/IFNO/POLNO per FREQ_ID
    currFreqId=freqIdCol(0);
    ftabRow = fidMap[currFreqId];
    // Assumes an identical number of channels per FREQ_ID
    if (fIdchans(ftabRow) < 0 ) {
      RORecordFieldPtr< Array<Float> > spec(rec, "SPECTRA");
      fIdchans(ftabRow)=(*spec).shape()(0);
    }
    // Should keep ifNos and polNos form the previous SCANNO
    if ( !anyEQ(ifNos[ftabRow],ifNoCol(0)) ) {
      ifNos[ftabRow].shape(iflen);
      iflen++;
      ifNos[ftabRow].resize(iflen,True);
      ifNos[ftabRow](iflen-1) = ifNoCol(0);
    }
    if ( !anyEQ(polNos[ftabRow],polNoCol(0)) ) {
      polNos[ftabRow].shape(pollen);
      pollen++;
      polNos[ftabRow].resize(pollen,True);
      polNos[ftabRow](pollen-1) = polNoCol(0);
    }

    for (uInt i=1; i < snrow; i++){
      // Need to list BEAMNO and DIRECTION in the same order
      if ( !anyEQ(beamids,beamCol(i)) ) {
        nbeam++;
        beamids.resize(nbeam,True);
        beamids(nbeam-1)=beamCol(i);
        beamDirs.resize(nbeam,True);
        beamDirs(nbeam-1)=dirCol(i);
      }

      // SRCTYPE is Int (getNumber takes only uInt)
      if ( !anyEQ(stypeids,stypeCol(i)) ) {
        nstype++;
        stypeids.resize(nstype,True);
        stypeids(nstype-1)=stypeCol(i);
      }

      // Global listings of nchan/IFNO/POLNO per FREQ_ID
      currFreqId=freqIdCol(i);
      ftabRow = fidMap[currFreqId];
      if (fIdchans(ftabRow) < 0 ) {
        const TableRecord& rec = row.get(i);
        RORecordFieldPtr< Array<Float> > spec(rec, "SPECTRA");
        fIdchans(ftabRow) = (*spec).shape()(0);
      }
      if ( !anyEQ(ifNos[ftabRow],ifNoCol(i)) ) {
        ifNos[ftabRow].shape(iflen);
        iflen++;
        ifNos[ftabRow].resize(iflen,True);
        ifNos[ftabRow](iflen-1) = ifNoCol(i);
      }
      if ( !anyEQ(polNos[ftabRow],polNoCol(i)) ) {
        polNos[ftabRow].shape(pollen);
        pollen++;
        polNos[ftabRow].resize(pollen,True);
        polNos[ftabRow](pollen-1) = polNoCol(i);
      }
    } // end of row iteration

    stypestrs.resize(nstype,False);
    for (uInt j=0; j < nstype; j++)
      stypestrs(j) = SrcType::getName(stypeids(j));

    // Format Scan summary
    oss << setw(4) << std::right << rec.asuInt("SCANNO")
        << std::left << setw(1) << ""
        << setw(15) << rec.asString("SRCNAME")
        << setw(21) << MVTime(btime).string(MVTime::YMD,7)
        << setw(3) << " - " << MVTime(etime).string(MVTime::TIME,7)
        << setw(3) << "" << setw(6) << meanIntTim << setw(1) << "" 
        << std::right << setw(5) << snrow << setw(2) << ""
        << std::left << stypestrs << setw(1) << ""
        << freqids << setw(1) << ""
        << molids  << endl;
    // Format Beam summary
    for (uInt j=0; j < nbeam; j++) {
      oss << setw(7) << "" << setw(6) << beamids(j) << setw(1) << ""
          << formatDirection(beamDirs(j)) << endl;
    }
    // Flush summary every scan and clear up the string
    ols << String(oss) << LogIO::POST;
    if (ofs) ofs << String(oss) << flush;
    oss.str("");
    oss.clear();

    ++iter;
  } // end of scan iteration
  oss << asap::SEPERATOR << endl;
  
  // List FRECUENCIES Table (using STFrequencies.print may be slow)
  oss << "FREQUENCIES: " << nfreq << endl;
  oss << std::right << setw(5) << "ID" << setw(2) << ""
      << std::left  << setw(5) << "IFNO" << setw(2) << ""
      << setw(8) << "Frame"
      << setw(16) << "RefVal"
      << setw(7) << "RefPix"
      << setw(15) << "Increment"
      << setw(9) << "Channels"
      << setw(6) << "POLNOs" << endl;
  Int tmplen;
  for (Int i=0; i < nfid; i++){
    // List row=i of FREQUENCIES subtable
    ifNos[i].shape(tmplen);
    if (tmplen == 1) {
      oss << std::right << setw(5) << ftabIds(i) << setw(2) << ""
          << setw(3) << ifNos[i](0) << setw(1) << ""
          << std::left << setw(46) << frequencies().print(ftabIds(i)) 
          << setw(2) << ""
          << std::right << setw(8) << fIdchans[i] << setw(2) << ""
          << std::left << polNos[i] << endl;
    } else if (tmplen > 0 ) {
      // You shouldn't come here
      oss << std::left
          << "Multiple IFNOs in FREQ_ID = " << ftabIds(i) 
          << " !!!" << endl;
    }
  }
  oss << asap::SEPERATOR << endl;

  // List MOLECULES Table (currently lists all rows)
  oss << "MOLECULES: " << endl;
  if (molecules().nrow() <= 0) {
    oss << "   MOLECULES subtable is empty: there are no data" << endl;
  } else {
    ROTableRow row(molecules().table());
    oss << std::right << setw(5) << "ID" 
        << std::left << setw(3) << ""
        << setw(18) << "RestFreq"
        << setw(15) << "Name" << endl;
    for (Int i=0; i < molecules().nrow(); i++){
      const TableRecord& rec=row.get(i);
      oss << std::right << setw(5) << rec.asuInt("ID")
          << std::left << setw(3) << ""
          << rec.asArrayDouble("RESTFREQUENCY") << setw(1) << ""
          << rec.asArrayString("NAME") << endl;
    }
  }
  oss << asap::SEPERATOR << endl;
  ols << String(oss) << LogIO::POST;
  if (ofs) {
    ofs << String(oss) << flush;
    ofs.close();
  }
  //  return String(oss);
}


std::string Scantable::oldheaderSummary()
{
  // Format header info
//   STHeader sdh;
//   sdh = getHeader();
//   sdh.print();
  ostringstream oss;
  oss.flags(std::ios_base::left);
  oss << setw(15) << "Beams:" << setw(4) << nbeam() << endl
      << setw(15) << "IFs:" << setw(4) << nif() << endl
      << setw(15) << "Polarisations:" << setw(4) << npol()
      << "(" << getPolType() << ")" << endl
      << setw(15) << "Channels:" << nchan() << endl;
  String tmp;
  oss << setw(15) << "Observer:"
      << table_.keywordSet().asString("Observer") << endl;
  oss << setw(15) << "Obs Date:" << getTime(-1,true) << endl;
  table_.keywordSet().get("Project", tmp);
  oss << setw(15) << "Project:" << tmp << endl;
  table_.keywordSet().get("Obstype", tmp);
  oss << setw(15) << "Obs. Type:" << tmp << endl;
  table_.keywordSet().get("AntennaName", tmp);
  oss << setw(15) << "Antenna Name:" << tmp << endl;
  table_.keywordSet().get("FluxUnit", tmp);
  oss << setw(15) << "Flux Unit:" << tmp << endl;
  int nid = moleculeTable_.nrow();
  Bool firstline = True;
  oss << setw(15) << "Rest Freqs:";
  for (int i=0; i<nid; i++) {
    Table t = table_(table_.col("MOLECULE_ID") == i, 1);
      if (t.nrow() >  0) {
          Vector<Double> vec(moleculeTable_.getRestFrequency(i));
          if (vec.nelements() > 0) {
               if (firstline) {
                   oss << setprecision(10) << vec << " [Hz]" << endl;
                   firstline=False;
               }
               else{
                   oss << setw(15)<<" " << setprecision(10) << vec << " [Hz]" << endl;
               }
          } else {
              oss << "none" << endl;
          }
      }
  }

  oss << setw(15) << "Abcissa:" << getAbcissaLabel(0) << endl;
  oss << selector_.print() << endl;
  return String(oss);
}

  //std::string Scantable::summary( const std::string& filename )
void Scantable::oldsummary( const std::string& filename )
{
  ostringstream oss;
  ofstream ofs;
  LogIO ols(LogOrigin("Scantable", "summary", WHERE));

  if (filename != "")
    ofs.open( filename.c_str(),  ios::out );

  oss << endl;
  oss << asap::SEPERATOR << endl;
  oss << " Scan Table Summary" << endl;
  oss << asap::SEPERATOR << endl;

  // Format header info
  oss << oldheaderSummary();
  oss << endl;

  // main table
  String dirtype = "Position ("
                  + getDirectionRefString()
                  + ")";
  oss.flags(std::ios_base::left);
  oss << setw(5) << "Scan" << setw(15) << "Source"
      << setw(10) << "Time" << setw(18) << "Integration" 
      << setw(15) << "Source Type" << endl;
  oss << setw(5) << "" << setw(5) << "Beam" << setw(3) << "" << dirtype << endl;
  oss << setw(10) << "" << setw(3) << "IF" << setw(3) << ""
      << setw(8) << "Frame" << setw(16)
      << "RefVal" << setw(10) << "RefPix" << setw(12) << "Increment"
      << setw(7) << "Channels"
      << endl;
  oss << asap::SEPERATOR << endl;

  // Flush summary and clear up the string
  ols << String(oss) << LogIO::POST;
  if (ofs) ofs << String(oss) << flush;
  oss.str("");
  oss.clear();

  TableIterator iter(table_, "SCANNO");
  while (!iter.pastEnd()) {
    Table subt = iter.table();
    ROTableRow row(subt);
    MEpoch::ROScalarColumn timeCol(subt,"TIME");
    const TableRecord& rec = row.get(0);
    oss << setw(4) << std::right << rec.asuInt("SCANNO")
        << std::left << setw(1) << ""
        << setw(15) << rec.asString("SRCNAME")
        << setw(10) << formatTime(timeCol(0), false);
    // count the cycles in the scan
    TableIterator cyciter(subt, "CYCLENO");
    int nint = 0;
    while (!cyciter.pastEnd()) {
      ++nint;
      ++cyciter;
    }
    oss << setw(3) << std::right << nint  << setw(3) << " x " << std::left
        << setw(11) <<  formatSec(rec.asFloat("INTERVAL")) << setw(1) << ""
        << setw(15) << SrcType::getName(rec.asInt("SRCTYPE")) << endl;

    TableIterator biter(subt, "BEAMNO");
    while (!biter.pastEnd()) {
      Table bsubt = biter.table();
      ROTableRow brow(bsubt);
      const TableRecord& brec = brow.get(0);
      uInt row0 = bsubt.rowNumbers(table_)[0];
      oss << setw(5) << "" <<  setw(4) << std::right << brec.asuInt("BEAMNO")<< std::left;
      oss  << setw(4) << ""  << formatDirection(getDirection(row0)) << endl;
      TableIterator iiter(bsubt, "IFNO");
      while (!iiter.pastEnd()) {
        Table isubt = iiter.table();
        ROTableRow irow(isubt);
        const TableRecord& irec = irow.get(0);
        oss << setw(9) << "";
        oss << setw(3) << std::right << irec.asuInt("IFNO") << std::left
            << setw(1) << "" << frequencies().print(irec.asuInt("FREQ_ID"))
            << setw(3) << "" << nchan(irec.asuInt("IFNO"))
            << endl;

        ++iiter;
      }
      ++biter;
    }
    // Flush summary every scan and clear up the string
    ols << String(oss) << LogIO::POST;
    if (ofs) ofs << String(oss) << flush;
    oss.str("");
    oss.clear();

    ++iter;
  }
  oss << asap::SEPERATOR << endl;
  ols << String(oss) << LogIO::POST;
  if (ofs) {
    ofs << String(oss) << flush;
    ofs.close();
  }
  //  return String(oss);
}

// std::string Scantable::getTime(int whichrow, bool showdate) const
// {
//   MEpoch::ROScalarColumn timeCol(table_, "TIME");
//   MEpoch me;
//   if (whichrow > -1) {
//     me = timeCol(uInt(whichrow));
//   } else {
//     Double tm;
//     table_.keywordSet().get("UTC",tm);
//     me = MEpoch(MVEpoch(tm));
//   }
//   return formatTime(me, showdate);
// }

std::string Scantable::getTime(int whichrow, bool showdate, uInt prec) const
{
  MEpoch me;
  me = getEpoch(whichrow);
  return formatTime(me, showdate, prec);
}

MEpoch Scantable::getEpoch(int whichrow) const
{
  if (whichrow > -1) {
    return timeCol_(uInt(whichrow));
  } else {
    Double tm;
    table_.keywordSet().get("UTC",tm);
    return MEpoch(MVEpoch(tm));
  }
}

std::string Scantable::getDirectionString(int whichrow) const
{
  return formatDirection(getDirection(uInt(whichrow)));
}


SpectralCoordinate Scantable::getSpectralCoordinate(int whichrow) const {
  const MPosition& mp = getAntennaPosition();
  const MDirection& md = getDirection(whichrow);
  const MEpoch& me = timeCol_(whichrow);
  //Double rf = moleculeTable_.getRestFrequency(mmolidCol_(whichrow));
  Vector<Double> rf = moleculeTable_.getRestFrequency(mmolidCol_(whichrow));
  return freqTable_.getSpectralCoordinate(md, mp, me, rf,
                                          mfreqidCol_(whichrow));
}

std::vector< double > Scantable::getAbcissa( int whichrow ) const
{
  if ( whichrow > int(table_.nrow()) ) throw(AipsError("Illegal row number"));
  std::vector<double> stlout;
  int nchan = specCol_(whichrow).nelements();
  String us = freqTable_.getUnitString();
  if ( us == "" || us == "pixel" || us == "channel" ) {
    for (int i=0; i<nchan; ++i) {
      stlout.push_back(double(i));
    }
    return stlout;
  }
  SpectralCoordinate spc = getSpectralCoordinate(whichrow);
  Vector<Double> pixel(nchan);
  Vector<Double> world;
  indgen(pixel);
  if ( Unit(us) == Unit("Hz") ) {
    for ( int i=0; i < nchan; ++i) {
      Double world;
      spc.toWorld(world, pixel[i]);
      stlout.push_back(double(world));
    }
  } else if ( Unit(us) == Unit("km/s") ) {
    Vector<Double> world;
    spc.pixelToVelocity(world, pixel);
    world.tovector(stlout);
  }
  return stlout;
}
void Scantable::setDirectionRefString( const std::string & refstr )
{
  MDirection::Types mdt;
  if (refstr != "" && !MDirection::getType(mdt, refstr)) {
    throw(AipsError("Illegal Direction frame."));
  }
  if ( refstr == "" ) {
    String defaultstr = MDirection::showType(dirCol_.getMeasRef().getType());
    table_.rwKeywordSet().define("DIRECTIONREF", defaultstr);
  } else {
    table_.rwKeywordSet().define("DIRECTIONREF", String(refstr));
  }
}

std::string Scantable::getDirectionRefString( ) const
{
  return table_.keywordSet().asString("DIRECTIONREF");
}

MDirection Scantable::getDirection(int whichrow ) const
{
  String usertype = table_.keywordSet().asString("DIRECTIONREF");
  String type = MDirection::showType(dirCol_.getMeasRef().getType());
  if ( usertype != type ) {
    MDirection::Types mdt;
    if (!MDirection::getType(mdt, usertype)) {
      throw(AipsError("Illegal Direction frame."));
    }
    return dirCol_.convert(uInt(whichrow), mdt);
  } else {
    return dirCol_(uInt(whichrow));
  }
}

std::string Scantable::getAbcissaLabel( int whichrow ) const
{
  if ( whichrow > int(table_.nrow()) ) throw(AipsError("Illegal ro number"));
  const MPosition& mp = getAntennaPosition();
  const MDirection& md = getDirection(whichrow);
  const MEpoch& me = timeCol_(whichrow);
  //const Double& rf = mmolidCol_(whichrow);
  const Vector<Double> rf = moleculeTable_.getRestFrequency(mmolidCol_(whichrow));
  SpectralCoordinate spc =
    freqTable_.getSpectralCoordinate(md, mp, me, rf, mfreqidCol_(whichrow));

  String s = "Channel";
  Unit u = Unit(freqTable_.getUnitString());
  if (u == Unit("km/s")) {
    s = CoordinateUtil::axisLabel(spc, 0, True,True,  True);
  } else if (u == Unit("Hz")) {
    Vector<String> wau(1);wau = u.getName();
    spc.setWorldAxisUnits(wau);
    s = CoordinateUtil::axisLabel(spc, 0, True, True, False);
  }
  return s;

}

/**
void asap::Scantable::setRestFrequencies( double rf, const std::string& name,
                                          const std::string& unit )
**/
void Scantable::setRestFrequencies( vector<double> rf, const vector<std::string>& name,
                                          const std::string& unit )

{
  ///@todo lookup in line table to fill in name and formattedname
  Unit u(unit);
  //Quantum<Double> urf(rf, u);
  Quantum<Vector<Double> >urf(rf, u);
  Vector<String> formattedname(0);
  //cerr<<"Scantable::setRestFrequnecies="<<urf<<endl;

  //uInt id = moleculeTable_.addEntry(urf.getValue("Hz"), name, "");
  uInt id = moleculeTable_.addEntry(urf.getValue("Hz"), mathutil::toVectorString(name), formattedname);
  TableVector<uInt> tabvec(table_, "MOLECULE_ID");
  tabvec = id;
}

/**
void asap::Scantable::setRestFrequencies( const std::string& name )
{
  throw(AipsError("setRestFrequencies( const std::string& name ) NYI"));
  ///@todo implement
}
**/

void Scantable::setRestFrequencies( const vector<std::string>& name )
{
  (void) name; // suppress unused warning
  throw(AipsError("setRestFrequencies( const vector<std::string>& name ) NYI"));
  ///@todo implement
}

std::vector< unsigned int > Scantable::rownumbers( ) const
{
  std::vector<unsigned int> stlout;
  Vector<uInt> vec = table_.rowNumbers();
  vec.tovector(stlout);
  return stlout;
}


Matrix<Float> Scantable::getPolMatrix( uInt whichrow ) const
{
  ROTableRow row(table_);
  const TableRecord& rec = row.get(whichrow);
  Table t =
    originalTable_( originalTable_.col("SCANNO") == Int(rec.asuInt("SCANNO"))
                    && originalTable_.col("BEAMNO") == Int(rec.asuInt("BEAMNO"))
                    && originalTable_.col("IFNO") == Int(rec.asuInt("IFNO"))
                    && originalTable_.col("CYCLENO") == Int(rec.asuInt("CYCLENO")) );
  ROArrayColumn<Float> speccol(t, "SPECTRA");
  return speccol.getColumn();
}

std::vector< std::string > Scantable::columnNames( ) const
{
  Vector<String> vec = table_.tableDesc().columnNames();
  return mathutil::tovectorstring(vec);
}

MEpoch::Types Scantable::getTimeReference( ) const
{
  return MEpoch::castType(timeCol_.getMeasRef().getType());
}

void Scantable::addFit( const STFitEntry& fit, int row )
{
  //cout << mfitidCol_(uInt(row)) << endl;
  LogIO os( LogOrigin( "Scantable", "addFit()", WHERE ) ) ;
  os << mfitidCol_(uInt(row)) << LogIO::POST ;
  uInt id = fitTable_.addEntry(fit, mfitidCol_(uInt(row)));
  mfitidCol_.put(uInt(row), id);
}

void Scantable::shift(int npix)
{
  Vector<uInt> fids(mfreqidCol_.getColumn());
  genSort( fids, Sort::Ascending,
           Sort::QuickSort|Sort::NoDuplicates );
  for (uInt i=0; i<fids.nelements(); ++i) {
    frequencies().shiftRefPix(npix, fids[i]);
  }
}

String Scantable::getAntennaName() const
{
  String out;
  table_.keywordSet().get("AntennaName", out);
  String::size_type pos1 = out.find("@") ;
  String::size_type pos2 = out.find("//") ;
  if ( pos2 != String::npos ) 
    out = out.substr(pos2+2,pos1-pos2-2) ;
  else if ( pos1 != String::npos )
    out = out.substr(0,pos1) ;
  return out;
}

int Scantable::checkScanInfo(const std::vector<int>& scanlist) const
{
  String tbpath;
  int ret = 0;
  if ( table_.keywordSet().isDefined("GBT_GO") ) {
    table_.keywordSet().get("GBT_GO", tbpath);
    Table t(tbpath,Table::Old);
    // check each scan if other scan of the pair exist
    int nscan = scanlist.size();
    for (int i = 0; i < nscan; i++) {
      Table subt = t( t.col("SCAN") == scanlist[i]+1 );
      if (subt.nrow()==0) {
        //cerr <<"Scan "<<scanlist[i]<<" cannot be found in the scantable."<<endl;
        LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
        os <<LogIO::WARN<<"Scan "<<scanlist[i]<<" cannot be found in the scantable."<<LogIO::POST;
        ret = 1;
        break;
      }
      ROTableRow row(subt);
      const TableRecord& rec = row.get(0);
      int scan1seqn = rec.asuInt("PROCSEQN");
      int laston1 = rec.asuInt("LASTON");
      if ( rec.asuInt("PROCSIZE")==2 ) {
        if ( i < nscan-1 ) {
          Table subt2 = t( t.col("SCAN") == scanlist[i+1]+1 );
          if ( subt2.nrow() == 0) {
            LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;

            //cerr<<"Scan "<<scanlist[i+1]<<" cannot be found in the scantable."<<endl;
            os<<LogIO::WARN<<"Scan "<<scanlist[i+1]<<" cannot be found in the scantable."<<LogIO::POST;
            ret = 1;
            break;
          }
          ROTableRow row2(subt2);
          const TableRecord& rec2 = row2.get(0);
          int scan2seqn = rec2.asuInt("PROCSEQN");
          int laston2 = rec2.asuInt("LASTON");
          if (scan1seqn == 1 && scan2seqn == 2) {
            if (laston1 == laston2) {
              LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
              //cerr<<"A valid scan pair ["<<scanlist[i]<<","<<scanlist[i+1]<<"]"<<endl;
              os<<"A valid scan pair ["<<scanlist[i]<<","<<scanlist[i+1]<<"]"<<LogIO::POST;
              i +=1;
            }
            else {
              LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
              //cerr<<"Incorrect scan pair ["<<scanlist[i]<<","<<scanlist[i+1]<<"]"<<endl;
              os<<LogIO::WARN<<"Incorrect scan pair ["<<scanlist[i]<<","<<scanlist[i+1]<<"]"<<LogIO::POST;
            }
          }
          else if (scan1seqn==2 && scan2seqn == 1) {
            if (laston1 == laston2) {
              LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
              //cerr<<"["<<scanlist[i]<<","<<scanlist[i+1]<<"] is a valid scan pair but in incorrect order."<<endl;
              os<<LogIO::WARN<<"["<<scanlist[i]<<","<<scanlist[i+1]<<"] is a valid scan pair but in incorrect order."<<LogIO::POST;
              ret = 1;
              break;
            }
          }
          else {
            LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
            //cerr<<"The other scan for  "<<scanlist[i]<<" appears to be missing. Check the input scan numbers."<<endl;
            os<<LogIO::WARN<<"The other scan for  "<<scanlist[i]<<" appears to be missing. Check the input scan numbers."<<LogIO::POST;
            ret = 1;
            break;
          }
        }
      }
      else {
        LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
        //cerr<<"The scan does not appear to be standard obsevation."<<endl;
        os<<LogIO::WARN<<"The scan does not appear to be standard obsevation."<<LogIO::POST;
      }
    //if ( i >= nscan ) break;
    }
  }
  else {
    LogIO os( LogOrigin( "Scantable", "checkScanInfo()", WHERE ) ) ;
    //cerr<<"No reference to GBT_GO table."<<endl;
    os<<LogIO::WARN<<"No reference to GBT_GO table."<<LogIO::POST;
    ret = 1;
  }
  return ret;
}

std::vector<double> Scantable::getDirectionVector(int whichrow) const
{
  Vector<Double> Dir = dirCol_(whichrow).getAngle("rad").getValue();
  std::vector<double> dir;
  Dir.tovector(dir);
  return dir;
}

void asap::Scantable::reshapeSpectrum( int nmin, int nmax )
  throw( casa::AipsError )
{
  // assumed that all rows have same nChan
  Vector<Float> arr = specCol_( 0 ) ;
  int nChan = arr.nelements() ;

  // if nmin < 0 or nmax < 0, nothing to do
  if (  nmin < 0 ) {
    throw( casa::indexError<int>( nmin, "asap::Scantable::reshapeSpectrum: Invalid range. Negative index is specified." ) ) ;
    }
  if (  nmax < 0  ) {
    throw( casa::indexError<int>( nmax, "asap::Scantable::reshapeSpectrum: Invalid range. Negative index is specified." ) ) ;
  }

  // if nmin > nmax, exchange values
  if ( nmin > nmax ) {
    int tmp = nmax ;
    nmax = nmin ;
    nmin = tmp ;
    LogIO os( LogOrigin( "Scantable", "reshapeSpectrum()", WHERE ) ) ;
    os << "Swap values. Applied range is ["
       << nmin << ", " << nmax << "]" << LogIO::POST ;
  }

  // if nmin exceeds nChan, nothing to do
  if ( nmin >= nChan ) {
    throw( casa::indexError<int>( nmin, "asap::Scantable::reshapeSpectrum: Invalid range. Specified minimum exceeds nChan." ) ) ;
  }

  // if nmax exceeds nChan, reset nmax to nChan
  if ( nmax >= nChan ) {
    if ( nmin == 0 ) {
      // nothing to do
      LogIO os( LogOrigin( "Scantable", "reshapeSpectrum()", WHERE ) ) ;
      os << "Whole range is selected. Nothing to do." << LogIO::POST ;
      return ;
    }
    else {
      LogIO os( LogOrigin( "Scantable", "reshapeSpectrum()", WHERE ) ) ;
      os << "Specified maximum exceeds nChan. Applied range is ["
         << nmin << ", " << nChan-1 << "]." << LogIO::POST ;
      nmax = nChan - 1 ;
    }
  }

  // reshape specCol_ and flagCol_
  for ( int irow = 0 ; irow < nrow() ; irow++ ) {
    reshapeSpectrum( nmin, nmax, irow ) ;
  }

  // update FREQUENCIES subtable
  Double refpix ;
  Double refval ;
  Double increment ;
  int freqnrow = freqTable_.table().nrow() ;
  Vector<uInt> oldId( freqnrow ) ;
  Vector<uInt> newId( freqnrow ) ;
  for ( int irow = 0 ; irow < freqnrow ; irow++ ) {
    freqTable_.getEntry( refpix, refval, increment, irow ) ;
    /***
     * need to shift refpix to nmin
     * note that channel nmin in old index will be channel 0 in new one
     ***/
    refval = refval - ( refpix - nmin ) * increment ;
    refpix = 0 ;
    freqTable_.setEntry( refpix, refval, increment, irow ) ;
  }

  // update nchan
  int newsize = nmax - nmin + 1 ;
  table_.rwKeywordSet().define( "nChan", newsize ) ;

  // update bandwidth
  // assumed all spectra in the scantable have same bandwidth
  table_.rwKeywordSet().define( "Bandwidth", increment * newsize ) ;

  return ;
}

void asap::Scantable::reshapeSpectrum( int nmin, int nmax, int irow )
{
  // reshape specCol_ and flagCol_
  Vector<Float> oldspec = specCol_( irow ) ;
  Vector<uChar> oldflag = flagsCol_( irow ) ;
  Vector<Float> oldtsys = tsysCol_( irow ) ;
  uInt newsize = nmax - nmin + 1 ;
  Slice slice( nmin, newsize, 1 ) ;
  specCol_.put( irow, oldspec( slice ) ) ;
  flagsCol_.put( irow, oldflag( slice ) ) ;
  if ( oldspec.size() == oldtsys.size() )
    tsysCol_.put( irow, oldtsys( slice ) ) ;

  return ;
}

void asap::Scantable::regridSpecChannel( double dnu, int nChan )
{
  LogIO os( LogOrigin( "Scantable", "regridChannel()", WHERE ) ) ;
  os << "Regrid abcissa with spectral resoultion " << dnu << " " << freqTable_.getUnitString() << " with channel number " << ((nChan>0)? String(nChan) : "covering band width")<< LogIO::POST ;
  int freqnrow = freqTable_.table().nrow() ;
  Vector<bool> firstTime( freqnrow, true ) ;
  double oldincr, factor;
  uInt currId;
  Double refpix ;
  Double refval ;
  Double increment ;
  for ( int irow = 0 ; irow < nrow() ; irow++ ) {
    currId = mfreqidCol_(irow);
    vector<double> abcissa = getAbcissa( irow ) ;
    if (nChan < 0) {
      int oldsize = abcissa.size() ;
      double bw = (abcissa[oldsize-1]-abcissa[0]) +                     \
        0.5 * (abcissa[1]-abcissa[0] + abcissa[oldsize-1]-abcissa[oldsize-2]) ;
      nChan = int( ceil( abs(bw/dnu) ) ) ;
    }
    // actual regridding
    regridChannel( nChan, dnu, irow ) ;

    // update FREQUENCIES subtable
    if (firstTime[currId]) {
      oldincr = abcissa[1]-abcissa[0] ;
      factor = dnu/oldincr ;
      firstTime[currId] = false ;
      freqTable_.getEntry( refpix, refval, increment, currId ) ;

      //refval = refval - ( refpix + 0.5 * (1 - factor) ) * increment ;
      if (factor > 0 ) {
        refpix = (refpix + 0.5)/factor - 0.5;
      } else {
        refpix = (abcissa.size() - 0.5 - refpix)/abs(factor) - 0.5;
      }
      freqTable_.setEntry( refpix, refval, increment*factor, currId ) ;
      //os << "ID" << currId << ": channel width (Orig) = " << oldincr << " [" << freqTable_.getUnitString() << "], scale factor = " << factor << LogIO::POST ;
      //os << "     frequency increment (Orig) = " << increment << "-> (New) " << increment*factor << LogIO::POST ;
    }
  }
}

void asap::Scantable::regridChannel( int nChan, double dnu )
{
  LogIO os( LogOrigin( "Scantable", "regridChannel()", WHERE ) ) ;
  os << "Regrid abcissa with channel number " << nChan << " and spectral resoultion " << dnu << "Hz." << LogIO::POST ;
  // assumed that all rows have same nChan
  Vector<Float> arr = specCol_( 0 ) ;
  int oldsize = arr.nelements() ;

  // if oldsize == nChan, nothing to do
  if ( oldsize == nChan ) {
    os << "Specified channel number is same as current one. Nothing to do." << LogIO::POST ;
    return ;
  }

  // if oldChan < nChan, unphysical operation
  if ( oldsize < nChan ) {
    os << "Unphysical operation. Nothing to do." << LogIO::POST ;
    return ;
  }

  // change channel number for specCol_, flagCol_, and tsysCol_ (if necessary)
  vector<string> coordinfo = getCoordInfo() ;
  string oldinfo = coordinfo[0] ;
  coordinfo[0] = "Hz" ;
  setCoordInfo( coordinfo ) ;
  for ( int irow = 0 ; irow < nrow() ; irow++ ) {
    regridChannel( nChan, dnu, irow ) ;
  }
  coordinfo[0] = oldinfo ;
  setCoordInfo( coordinfo ) ;


  // NOTE: this method does not update metadata such as
  //       FREQUENCIES subtable, nChan, Bandwidth, etc.

  return ;
}

void asap::Scantable::regridChannel( int nChan, double dnu, int irow )
{
  // logging
  //ofstream ofs( "average.log", std::ios::out | std::ios::app ) ;
  //ofs << "IFNO = " << getIF( irow ) << " irow = " << irow << endl ;

  Vector<Float> oldspec = specCol_( irow ) ;
  Vector<uChar> oldflag = flagsCol_( irow ) ;
  Vector<Float> oldtsys = tsysCol_( irow ) ;
  Vector<Float> newspec( nChan, 0 ) ;
  Vector<uChar> newflag( nChan, true ) ;
  Vector<Float> newtsys ;
  bool regridTsys = false ;
  if (oldtsys.size() == oldspec.size()) {
    regridTsys = true ;
    newtsys.resize(nChan,false) ;
    newtsys = 0 ;
  }

  // regrid
  vector<double> abcissa = getAbcissa( irow ) ;
  int oldsize = abcissa.size() ;
  double olddnu = abcissa[1] - abcissa[0] ;
  //int ichan = 0 ;
  double wsum = 0.0 ;
  Vector<double> zi( nChan+1 ) ;
  Vector<double> yi( oldsize + 1 ) ;
  yi[0] = abcissa[0] - 0.5 * olddnu ;
  for ( int ii = 1 ; ii < oldsize ; ii++ )
    yi[ii] = 0.5* (abcissa[ii-1] + abcissa[ii]) ;
  yi[oldsize] = abcissa[oldsize-1] \
    + 0.5 * (abcissa[oldsize-1] - abcissa[oldsize-2]) ;
  //zi[0] = abcissa[0] - 0.5 * olddnu ;
  zi[0] = ((olddnu*dnu > 0) ? yi[0] : yi[oldsize]) ;
  for ( int ii = 1 ; ii < nChan ; ii++ )
    zi[ii] = zi[0] + dnu * ii ;
  zi[nChan] = zi[nChan-1] + dnu ;
  // Access zi and yi in ascending order
  int izs = ((dnu > 0) ? 0 : nChan ) ;
  int ize = ((dnu > 0) ? nChan : 0 ) ;
  int izincr = ((dnu > 0) ? 1 : -1 ) ;
  int ichan =  ((olddnu > 0) ? 0 : oldsize ) ;
  int iye = ((olddnu > 0) ? oldsize : 0 ) ;
  int iyincr = ((olddnu > 0) ? 1 : -1 ) ;
  //for ( int ii = izs ; ii != ize ; ii+=izincr ){
  int ii = izs ;
  while (ii != ize) {
    // always zl < zr
    double zl = zi[ii] ;
    double zr = zi[ii+izincr] ;
    // Need to access smaller index for the new spec, flag, and tsys.
    // Values between zi[k] and zi[k+1] should be stored in newspec[k], etc.
    int i = min(ii, ii+izincr) ;
    //for ( int jj = ichan ; jj != iye ; jj+=iyincr ) {
    int jj = ichan ;
    while (jj != iye) {
      // always yl < yr
      double yl = yi[jj] ;
      double yr = yi[jj+iyincr] ;
      // Need to access smaller index for the original spec, flag, and tsys.
      // Values between yi[k] and yi[k+1] are stored in oldspec[k], etc.
      int j = min(jj, jj+iyincr) ;
      if ( yr <= zl ) {
        jj += iyincr ;
        continue ;
      }
      else if ( yl <= zl ) {
        if ( yr < zr ) {
          if (!oldflag[j]) {
            newspec[i] += oldspec[j] * ( yr - zl ) ;
            if (regridTsys) newtsys[i] += oldtsys[j] * ( yr - zl ) ;
            wsum += ( yr - zl ) ;
          }
          newflag[i] = newflag[i] && oldflag[j] ;
        }
        else {
          if (!oldflag[j]) {
            newspec[i] += oldspec[j] * abs(dnu) ;
            if (regridTsys) newtsys[i] += oldtsys[j] * abs(dnu) ;
            wsum += abs(dnu) ;
          }
          newflag[i] = newflag[i] && oldflag[j] ;
          ichan = jj ;
          break ;
        }
      }
      else if ( yl < zr ) {
        if ( yr <= zr ) {
          if (!oldflag[j]) {
            newspec[i] += oldspec[j] * ( yr - yl ) ;
            if (regridTsys) newtsys[i] += oldtsys[j] * ( yr - yl ) ;
            wsum += ( yr - yl ) ;
          }
          newflag[i] = newflag[i] && oldflag[j] ;
        }
        else {
          if (!oldflag[j]) {
            newspec[i] += oldspec[j] * ( zr - yl ) ;
            if (regridTsys) newtsys[i] += oldtsys[j] * ( zr - yl ) ;
            wsum += ( zr - yl ) ;
          }
          newflag[i] = newflag[i] && oldflag[j] ;
          ichan = jj ;
          break ;
        }
      }
      else {
        ichan = jj - iyincr ;
        break ;
      }
      jj += iyincr ;
    }
    if ( wsum != 0.0 ) {
      newspec[i] /= wsum ;
      if (regridTsys) newtsys[i] /= wsum ;
    }
    wsum = 0.0 ;
    ii += izincr ;
  }
//   if ( dnu > 0.0 ) {
//     for ( int ii = 0 ; ii < nChan ; ii++ ) {
//       double zl = zi[ii] ;
//       double zr = zi[ii+1] ;
//       for ( int j = ichan ; j < oldsize ; j++ ) {
//         double yl = yi[j] ;
//         double yr = yi[j+1] ;
//         if ( yl <= zl ) {
//           if ( yr <= zl ) {
//             continue ;
//           }
//           else if ( yr <= zr ) {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * ( yr - zl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * ( yr - zl ) ;
//            wsum += ( yr - zl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//           }
//           else {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * dnu ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * dnu ;
//            wsum += dnu ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//             ichan = j ;
//             break ;
//           }
//         }
//         else if ( yl < zr ) {
//           if ( yr <= zr ) {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * ( yr - yl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * ( yr - yl ) ;
//               wsum += ( yr - yl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//           }
//           else {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * ( zr - yl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * ( zr - yl ) ;
//            wsum += ( zr - yl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//             ichan = j ;
//             break ;
//           }
//         }
//         else {
//           ichan = j - 1 ;
//           break ;
//         }
//       }
//       if ( wsum != 0.0 ) {
//         newspec[ii] /= wsum ;
//      if (regridTsys) newtsys[ii] /= wsum ;
//       }
//       wsum = 0.0 ;
//     }
//   }
//   else if ( dnu < 0.0 ) {
//     for ( int ii = 0 ; ii < nChan ; ii++ ) {
//       double zl = zi[ii] ;
//       double zr = zi[ii+1] ;
//       for ( int j = ichan ; j < oldsize ; j++ ) {
//         double yl = yi[j] ;
//         double yr = yi[j+1] ;
//         if ( yl >= zl ) {
//           if ( yr >= zl ) {
//             continue ;
//           }
//           else if ( yr >= zr ) {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * abs( yr - zl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * abs( yr - zl ) ;
//            wsum += abs( yr - zl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//           }
//           else {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * abs( dnu ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * abs( dnu ) ;
//            wsum += abs( dnu ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//             ichan = j ;
//             break ;
//           }
//         }
//         else if ( yl > zr ) {
//           if ( yr >= zr ) {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * abs( yr - yl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * abs( yr - yl ) ;
//            wsum += abs( yr - yl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//           }
//           else {
//          if (!oldflag[j]) {
//            newspec[ii] += oldspec[j] * abs( zr - yl ) ;
//            if (regridTsys) newtsys[ii] += oldtsys[j] * abs( zr - yl ) ;
//            wsum += abs( zr - yl ) ;
//          }
//          newflag[ii] = newflag[ii] && oldflag[j] ;
//             ichan = j ;
//             break ;
//           }
//         }
//         else {
//           ichan = j - 1 ;
//           break ;
//         }
//       }
//       if ( wsum != 0.0 ) {
//         newspec[ii] /= wsum ;
//      if (regridTsys) newtsys[ii] /= wsum ;
//       }
//       wsum = 0.0 ;
//     }
//   }
// //   //ofs << "olddnu = " << olddnu << ", dnu = " << dnu << endl ;
// //   pile += dnu ;
// //   wedge = olddnu * ( refChan + 1 ) ;
// //   while ( wedge < pile ) {
// //     newspec[0] += olddnu * oldspec[refChan] ;
// //     newflag[0] = newflag[0] || oldflag[refChan] ;
// //     //ofs << "channel " << refChan << " is included in new channel 0" << endl ;
// //     refChan++ ;
// //     wedge += olddnu ;
// //     wsum += olddnu ;
// //     //ofs << "newspec[0] = " << newspec[0] << " wsum = " << wsum << endl ;
// //   }
// //   frac = ( wedge - pile ) / olddnu ;
// //   wsum += ( 1.0 - frac ) * olddnu ;
// //   newspec[0] += ( 1.0 - frac ) * olddnu * oldspec[refChan] ;
// //   newflag[0] = newflag[0] || oldflag[refChan] ;
// //   //ofs << "channel " << refChan << " is partly included in new channel 0" << " with fraction of " << ( 1.0 - frac ) << endl ;
// //   //ofs << "newspec[0] = " << newspec[0] << " wsum = " << wsum << endl ;
// //   newspec[0] /= wsum ;
// //   //ofs << "newspec[0] = " << newspec[0] << endl ;
// //   //ofs << "wedge = " << wedge << ", pile = " << pile << endl ;

// //   /***
// //    * ichan = 1 - nChan-2
// //    ***/
// //   for ( int ichan = 1 ; ichan < nChan - 1 ; ichan++ ) {
// //     pile += dnu ;
// //     newspec[ichan] += frac * olddnu * oldspec[refChan] ;
// //     newflag[ichan] = newflag[ichan] || oldflag[refChan] ;
// //     //ofs << "channel " << refChan << " is partly included in new channel " << ichan << " with fraction of " << frac << endl ;
// //     refChan++ ;
// //     wedge += olddnu ;
// //     wsum = frac * olddnu ;
// //     //ofs << "newspec[" << ichan << "] = " << newspec[ichan] << " wsum = " << wsum << endl ;
// //     while ( wedge < pile ) {
// //       newspec[ichan] += olddnu * oldspec[refChan] ;
// //       newflag[ichan] = newflag[ichan] || oldflag[refChan] ;
// //       //ofs << "channel " << refChan << " is included in new channel " << ichan << endl ;
// //       refChan++ ;
// //       wedge += olddnu ;
// //       wsum += olddnu ;
// //       //ofs << "newspec[" << ichan << "] = " << newspec[ichan] << " wsum = " << wsum << endl ;
// //     }
// //     frac = ( wedge - pile ) / olddnu ;
// //     wsum += ( 1.0 - frac ) * olddnu ;
// //     newspec[ichan] += ( 1.0 - frac ) * olddnu * oldspec[refChan] ;
// //     newflag[ichan] = newflag[ichan] || oldflag[refChan] ;
// //     //ofs << "channel " << refChan << " is partly included in new channel " << ichan << " with fraction of " << ( 1.0 - frac ) << endl ;
// //     //ofs << "wedge = " << wedge << ", pile = " << pile << endl ;
// //     //ofs << "newspec[" << ichan << "] = " << newspec[ichan] << " wsum = " << wsum << endl ;
// //     newspec[ichan] /= wsum ;
// //     //ofs << "newspec[" << ichan << "] = " << newspec[ichan] << endl ;
// //   }

// //   /***
// //    * ichan = nChan-1
// //    ***/
// //   // NOTE: Assumed that all spectra have the same bandwidth
// //   pile += dnu ;
// //   newspec[nChan-1] += frac * olddnu * oldspec[refChan] ;
// //   newflag[nChan-1] = newflag[nChan-1] || oldflag[refChan] ;
// //   //ofs << "channel " << refChan << " is partly included in new channel " << nChan-1 << " with fraction of " << frac << endl ;
// //   refChan++ ;
// //   wedge += olddnu ;
// //   wsum = frac * olddnu ;
// //   //ofs << "newspec[" << nChan - 1 << "] = " << newspec[nChan-1] << " wsum = " << wsum << endl ;
// //   for ( int jchan = refChan ; jchan < oldsize ; jchan++ ) {
// //     newspec[nChan-1] += olddnu * oldspec[jchan] ;
// //     newflag[nChan-1] = newflag[nChan-1] || oldflag[jchan] ;
// //     wsum += olddnu ;
// //     //ofs << "channel " << jchan << " is included in new channel " << nChan-1 << " with fraction of " << frac << endl ;
// //     //ofs << "newspec[" << nChan - 1 << "] = " << newspec[nChan-1] << " wsum = " << wsum << endl ;
// //   }
// //   //ofs << "wedge = " << wedge << ", pile = " << pile << endl ;
// //   //ofs << "newspec[" << nChan - 1 << "] = " << newspec[nChan-1] << " wsum = " << wsum << endl ;
// //   newspec[nChan-1] /= wsum ;
// //   //ofs << "newspec[" << nChan - 1 << "] = " << newspec[nChan-1] << endl ;

// //   // ofs.close() ;

  specCol_.put( irow, newspec ) ;
  flagsCol_.put( irow, newflag ) ;
  if (regridTsys) tsysCol_.put( irow, newtsys );

  return ;
}

std::vector<float> Scantable::getWeather(int whichrow) const
{
  std::vector<float> out(5);
  //Float temperature, pressure, humidity, windspeed, windaz;
  weatherTable_.getEntry(out[0], out[1], out[2], out[3], out[4],
                         mweatheridCol_(uInt(whichrow)));


  return out;
}

bool Scantable::getFlagtraFast(uInt whichrow)
{
  uChar flag;
  Vector<uChar> flags;
  flagsCol_.get(whichrow, flags);
  flag = flags[0];
  for (uInt i = 1; i < flags.size(); ++i) {
    flag &= flags[i];
  }
  return ((flag >> 7) == 1);
}

void Scantable::polyBaseline(const std::vector<bool>& mask, int order, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    Fitter fitter = Fitter();
    fitter.setExpression("poly", order);
    //fitter.setIterClipping(thresClip, nIterClip);

    int nRow = nrow();
    std::vector<bool> chanMask;
    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    for (int whichrow = 0; whichrow < nRow; ++whichrow) {
      chanMask = getCompositeChanMask(whichrow, mask);
      fitBaseline(chanMask, whichrow, fitter);
      setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);
      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "polyBaseline()", fitter);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }

    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

void Scantable::autoPolyBaseline(const std::vector<bool>& mask, int order, const std::vector<int>& edge, float threshold, int chanAvgLimit, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    Fitter fitter = Fitter();
    fitter.setExpression("poly", order);
    //fitter.setIterClipping(thresClip, nIterClip);

    int nRow = nrow();
    std::vector<bool> chanMask;
    int minEdgeSize = getIFNos().size()*2;
    STLineFinder lineFinder = STLineFinder();
    lineFinder.setOptions(threshold, 3, chanAvgLimit);

    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    for (int whichrow = 0; whichrow < nRow; ++whichrow) {

      //-------------------------------------------------------
      //chanMask = getCompositeChanMask(whichrow, mask, edge, minEdgeSize, lineFinder);
      //-------------------------------------------------------
      int edgeSize = edge.size();
      std::vector<int> currentEdge;
      if (edgeSize >= 2) {
        int idx = 0;
        if (edgeSize > 2) {
          if (edgeSize < minEdgeSize) {
            throw(AipsError("Length of edge element info is less than that of IFs"));
          }
          idx = 2 * getIF(whichrow);
        }
        currentEdge.push_back(edge[idx]);
        currentEdge.push_back(edge[idx+1]);
      } else {
        throw(AipsError("Wrong length of edge element"));
      }
      lineFinder.setData(getSpectrum(whichrow));
      lineFinder.findLines(getCompositeChanMask(whichrow, mask), currentEdge, whichrow);
      chanMask = lineFinder.getMask();
      //-------------------------------------------------------

      fitBaseline(chanMask, whichrow, fitter);
      setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);

      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "autoPolyBaseline()", fitter);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }

    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

void Scantable::cubicSplineBaseline(const std::vector<bool>& mask, int nPiece, float thresClip, int nIterClip, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    //Fitter fitter = Fitter();
    //fitter.setExpression("cspline", nPiece);
    //fitter.setIterClipping(thresClip, nIterClip);

    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    int nRow = nrow();
    std::vector<bool> chanMask;

    //--------------------------------
    for (int whichrow = 0; whichrow < nRow; ++whichrow) {
      chanMask = getCompositeChanMask(whichrow, mask);
      //fitBaseline(chanMask, whichrow, fitter);
      //setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);
      std::vector<int> pieceEdges(nPiece+1);
      std::vector<float> params(nPiece*4);
      int nClipped = 0;
      std::vector<float> res = doCubicSplineFitting(getSpectrum(whichrow), chanMask, nPiece, pieceEdges, params, nClipped, thresClip, nIterClip, getResidual);
      setSpectrum(res, whichrow);
      //

      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "cubicSplineBaseline()", pieceEdges, params, nClipped);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }
    //--------------------------------
    
    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

void Scantable::autoCubicSplineBaseline(const std::vector<bool>& mask, int nPiece, float thresClip, int nIterClip, const std::vector<int>& edge, float threshold, int chanAvgLimit, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    //Fitter fitter = Fitter();
    //fitter.setExpression("cspline", nPiece);
    //fitter.setIterClipping(thresClip, nIterClip);

    int nRow = nrow();
    std::vector<bool> chanMask;
    int minEdgeSize = getIFNos().size()*2;
    STLineFinder lineFinder = STLineFinder();
    lineFinder.setOptions(threshold, 3, chanAvgLimit);

    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    for (int whichrow = 0; whichrow < nRow; ++whichrow) {

      //-------------------------------------------------------
      //chanMask = getCompositeChanMask(whichrow, mask, edge, minEdgeSize, lineFinder);
      //-------------------------------------------------------
      int edgeSize = edge.size();
      std::vector<int> currentEdge;
      if (edgeSize >= 2) {
        int idx = 0;
        if (edgeSize > 2) {
          if (edgeSize < minEdgeSize) {
            throw(AipsError("Length of edge element info is less than that of IFs"));
          }
          idx = 2 * getIF(whichrow);
        }
        currentEdge.push_back(edge[idx]);
        currentEdge.push_back(edge[idx+1]);
      } else {
        throw(AipsError("Wrong length of edge element"));
      }
      lineFinder.setData(getSpectrum(whichrow));
      lineFinder.findLines(getCompositeChanMask(whichrow, mask), currentEdge, whichrow);
      chanMask = lineFinder.getMask();
      //-------------------------------------------------------


      //fitBaseline(chanMask, whichrow, fitter);
      //setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);
      std::vector<int> pieceEdges(nPiece+1);
      std::vector<float> params(nPiece*4);
      int nClipped = 0;
      std::vector<float> res = doCubicSplineFitting(getSpectrum(whichrow), chanMask, nPiece, pieceEdges, params, nClipped, thresClip, nIterClip, getResidual);
      setSpectrum(res, whichrow);
      //

      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "autoCubicSplineBaseline()", pieceEdges, params, nClipped);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }

    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

std::vector<float> Scantable::doCubicSplineFitting(const std::vector<float>& data, const std::vector<bool>& mask, int nPiece, std::vector<int>& idxEdge, std::vector<float>& params, int& nClipped, float thresClip, int nIterClip, bool getResidual)
{
  if (data.size() != mask.size()) {
    throw(AipsError("data and mask sizes are not identical"));
  }
  if (nPiece < 1) {
    throw(AipsError("number of the sections must be one or more"));
  }

  int nChan = data.size();
  std::vector<int> maskArray(nChan);
  std::vector<int> x(nChan);
  int j = 0;
  for (int i = 0; i < nChan; ++i) {
    maskArray[i] = mask[i] ? 1 : 0;
    if (mask[i]) {
      x[j] = i;
      j++;
    }
  }
  int initNData = j;

  if (initNData < nPiece) {
    throw(AipsError("too few non-flagged channels"));
  }

  int nElement = (int)(floor(floor((double)(initNData/nPiece))+0.5));
  std::vector<double> invEdge(nPiece-1);
  idxEdge[0] = x[0];
  for (int i = 1; i < nPiece; ++i) {
    int valX = x[nElement*i];
    idxEdge[i] = valX;
    invEdge[i-1] = 1.0/(double)valX;
  }
  idxEdge[nPiece] = x[initNData-1]+1;

  int nData = initNData;
  int nDOF = nPiece + 3;  //number of parameters to solve, namely, 4+(nPiece-1).

  std::vector<double> x1(nChan), x2(nChan), x3(nChan);
  std::vector<double> z1(nChan), x1z1(nChan), x2z1(nChan), x3z1(nChan);
  std::vector<double> r1(nChan), residual(nChan);
  for (int i = 0; i < nChan; ++i) {
    double di = (double)i;
    double dD = (double)data[i];
    x1[i]   = di;
    x2[i]   = di*di;
    x3[i]   = di*di*di;
    z1[i]   = dD;
    x1z1[i] = dD*di;
    x2z1[i] = dD*di*di;
    x3z1[i] = dD*di*di*di;
    r1[i]   = 0.0;
    residual[i] = 0.0;
  }

  for (int nClip = 0; nClip < nIterClip+1; ++nClip) {
    // xMatrix : horizontal concatenation of 
    //           the least-sq. matrix (left) and an 
    //           identity matrix (right).
    // the right part is used to calculate the inverse matrix of the left part. 
    double xMatrix[nDOF][2*nDOF];
    double zMatrix[nDOF];
    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < 2*nDOF; ++j) {
        xMatrix[i][j] = 0.0;
      }
      xMatrix[i][nDOF+i] = 1.0;
      zMatrix[i] = 0.0;
    }

    for (int n = 0; n < nPiece; ++n) {
      int nUseDataInPiece = 0;
      for (int i = idxEdge[n]; i < idxEdge[n+1]; ++i) {

        if (maskArray[i] == 0) continue;

        xMatrix[0][0] += 1.0;
        xMatrix[0][1] += x1[i];
        xMatrix[0][2] += x2[i];
        xMatrix[0][3] += x3[i];
        xMatrix[1][1] += x2[i];
        xMatrix[1][2] += x3[i];
        xMatrix[1][3] += x2[i]*x2[i];
        xMatrix[2][2] += x2[i]*x2[i];
        xMatrix[2][3] += x3[i]*x2[i];
        xMatrix[3][3] += x3[i]*x3[i];
        zMatrix[0] += z1[i];
        zMatrix[1] += x1z1[i];
        zMatrix[2] += x2z1[i];
        zMatrix[3] += x3z1[i];

        for (int j = 0; j < n; ++j) {
          double q = 1.0 - x1[i]*invEdge[j];
          q = q*q*q;
          xMatrix[0][j+4] += q;
          xMatrix[1][j+4] += q*x1[i];
          xMatrix[2][j+4] += q*x2[i];
          xMatrix[3][j+4] += q*x3[i];
          for (int k = 0; k < j; ++k) {
            double r = 1.0 - x1[i]*invEdge[k];
            r = r*r*r;
            xMatrix[k+4][j+4] += r*q;
          }
          xMatrix[j+4][j+4] += q*q;
          zMatrix[j+4] += q*z1[i];
        }

        nUseDataInPiece++;
      }

      if (nUseDataInPiece < 1) {
        std::vector<string> suffixOfPieceNumber(4);
        suffixOfPieceNumber[0] = "th";
        suffixOfPieceNumber[1] = "st";
        suffixOfPieceNumber[2] = "nd";
        suffixOfPieceNumber[3] = "rd";
        int idxNoDataPiece = (n % 10 <= 3) ? n : 0;
        ostringstream oss;
        oss << "all channels clipped or masked in " << n << suffixOfPieceNumber[idxNoDataPiece];
        oss << " piece of the spectrum. can't execute fitting anymore.";
        throw(AipsError(String(oss)));
      }
    }

    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < i; ++j) {
        xMatrix[i][j] = xMatrix[j][i];
      }
    }

    std::vector<double> invDiag(nDOF);
    for (int i = 0; i < nDOF; ++i) {
      invDiag[i] = 1.0/xMatrix[i][i];
      for (int j = 0; j < nDOF; ++j) {
        xMatrix[i][j] *= invDiag[i];
      }
    }

    for (int k = 0; k < nDOF; ++k) {
      for (int i = 0; i < nDOF; ++i) {
        if (i != k) {
          double factor1 = xMatrix[k][k];
          double factor2 = xMatrix[i][k];
          for (int j = k; j < 2*nDOF; ++j) {
            xMatrix[i][j] *= factor1;
            xMatrix[i][j] -= xMatrix[k][j]*factor2;
            xMatrix[i][j] /= factor1;
          }
        }
      }
      double xDiag = xMatrix[k][k];
      for (int j = k; j < 2*nDOF; ++j) {
        xMatrix[k][j] /= xDiag;
      }
    }
    
    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < nDOF; ++j) {
        xMatrix[i][nDOF+j] *= invDiag[j];
      }
    }
    //compute a vector y which consists of the coefficients of the best-fit spline curves 
    //(a0,a1,a2,a3(,b3,c3,...)), namely, the ones for the leftmost piece and the ones of 
    //cubic terms for the other pieces (in case nPiece>1).
    std::vector<double> y(nDOF);
    for (int i = 0; i < nDOF; ++i) {
      y[i] = 0.0;
      for (int j = 0; j < nDOF; ++j) {
        y[i] += xMatrix[i][nDOF+j]*zMatrix[j];
      }
    }

    double a0 = y[0];
    double a1 = y[1];
    double a2 = y[2];
    double a3 = y[3];

    int j = 0;
    for (int n = 0; n < nPiece; ++n) {
      for (int i = idxEdge[n]; i < idxEdge[n+1]; ++i) {
        r1[i] = a0 + a1*x1[i] + a2*x2[i] + a3*x3[i];
      }
      params[j]   = a0;
      params[j+1] = a1;
      params[j+2] = a2;
      params[j+3] = a3;
      j += 4;

      if (n == nPiece-1) break;

      double d = y[4+n];
      double iE = invEdge[n];
      a0 +=     d;
      a1 -= 3.0*d*iE;
      a2 += 3.0*d*iE*iE;
      a3 -=     d*iE*iE*iE;
    }

    //subtract constant value for masked regions at the edge of spectrum
    if (idxEdge[0] > 0) {
      int n = idxEdge[0];
      for (int i = 0; i < idxEdge[0]; ++i) {
        //--cubic extrapolate--
        //r1[i] = params[0] + params[1]*x1[i] + params[2]*x2[i] + params[3]*x3[i];
        //--linear extrapolate--
        //r1[i] = (r1[n+1] - r1[n])/(x1[n+1] - x1[n])*(x1[i] - x1[n]) + r1[n];
        //--constant--
        r1[i] = r1[n];
      }
    }
    if (idxEdge[nPiece] < nChan) {
      int n = idxEdge[nPiece]-1;
      for (int i = idxEdge[nPiece]; i < nChan; ++i) {
        //--cubic extrapolate--
        //int m = 4*(nPiece-1);
        //r1[i] = params[m] + params[m+1]*x1[i] + params[m+2]*x2[i] + params[m+3]*x3[i];
        //--linear extrapolate--
        //r1[i] = (r1[n-1] - r1[n])/(x1[n-1] - x1[n])*(x1[i] - x1[n]) + r1[n];
        //--constant--
        r1[i] = r1[n];
      }
    }

    for (int i = 0; i < nChan; ++i) {
      residual[i] = z1[i] - r1[i];
    }

    if ((nClip == nIterClip) || (thresClip <= 0.0)) {
      break;
    } else {
      double stdDev = 0.0;
      for (int i = 0; i < nChan; ++i) {
        stdDev += residual[i]*residual[i]*(double)maskArray[i];
      }
      stdDev = sqrt(stdDev/(double)nData);
      
      double thres = stdDev * thresClip;
      int newNData = 0;
      for (int i = 0; i < nChan; ++i) {
        if (abs(residual[i]) >= thres) {
          maskArray[i] = 0;
        }
        if (maskArray[i] > 0) {
          newNData++;
        }
      }
      if (newNData == nData) {
        break; //no more flag to add. iteration stops.
      } else {
        nData = newNData;
      }
    }
  }

  nClipped = initNData - nData;

  std::vector<float> result(nChan);
  if (getResidual) {
    for (int i = 0; i < nChan; ++i) {
      result[i] = (float)residual[i];
    }
  } else {
    for (int i = 0; i < nChan; ++i) {
      result[i] = (float)r1[i];
    }
  }

  return result;
}

void Scantable::selectWaveNumbers(const int whichrow, const std::vector<bool>& chanMask, const bool applyFFT, const std::string& fftMethod, const std::string& fftThresh, const std::vector<int>& addNWaves, const std::vector<int>& rejectNWaves, std::vector<int>& nWaves)
{
  nWaves.clear();

  if (applyFFT) {
    string fftThAttr;
    float fftThSigma;
    int fftThTop;
    parseThresholdExpression(fftThresh, fftThAttr, fftThSigma, fftThTop);
    doSelectWaveNumbers(whichrow, chanMask, fftMethod, fftThSigma, fftThTop, fftThAttr, nWaves);
  }

  addAuxWaveNumbers(whichrow, addNWaves, rejectNWaves, nWaves);
}

void Scantable::parseThresholdExpression(const std::string& fftThresh, std::string& fftThAttr, float& fftThSigma, int& fftThTop)
{
  uInt idxSigma = fftThresh.find("sigma");
  uInt idxTop   = fftThresh.find("top");

  if (idxSigma == fftThresh.size() - 5) {
    std::istringstream is(fftThresh.substr(0, fftThresh.size() - 5));
    is >> fftThSigma;
    fftThAttr = "sigma";
  } else if (idxTop == 0) {
    std::istringstream is(fftThresh.substr(3));
    is >> fftThTop;
    fftThAttr = "top";
  } else {
    bool isNumber = true;
    for (uInt i = 0; i < fftThresh.size()-1; ++i) {
      char ch = (fftThresh.substr(i, 1).c_str())[0];
      if (!(isdigit(ch) || (fftThresh.substr(i, 1) == "."))) {
        isNumber = false;
        break;
      }
    }
    if (isNumber) {
      std::istringstream is(fftThresh);
      is >> fftThSigma;
      fftThAttr = "sigma";
    } else {
      throw(AipsError("fftthresh has a wrong value"));
    }
  }
}

void Scantable::doSelectWaveNumbers(const int whichrow, const std::vector<bool>& chanMask, const std::string& fftMethod, const float fftThSigma, const int fftThTop, const std::string& fftThAttr, std::vector<int>& nWaves)
{
  std::vector<float> fspec;
  if (fftMethod == "fft") {
    fspec = execFFT(whichrow, chanMask, false, true);
  //} else if (fftMethod == "lsp") {
  //  fspec = lombScarglePeriodogram(whichrow);
  }

  if (fftThAttr == "sigma") {
    float mean  = 0.0;
    float mean2 = 0.0;
    for (uInt i = 0; i < fspec.size(); ++i) {
      mean  += fspec[i];
      mean2 += fspec[i]*fspec[i];
    }
    mean  /= float(fspec.size());
    mean2 /= float(fspec.size());
    float thres = mean + fftThSigma * float(sqrt(mean2 - mean*mean));

    for (uInt i = 0; i < fspec.size(); ++i) {
      if (fspec[i] >= thres) {
        nWaves.push_back(i);
      }
    }

  } else if (fftThAttr == "top") {
    for (int i = 0; i < fftThTop; ++i) {
      float max = 0.0;
      int maxIdx = 0;
      for (uInt j = 0; j < fspec.size(); ++j) {
        if (fspec[j] > max) {
          max = fspec[j];
          maxIdx = j;
        }
      }
      nWaves.push_back(maxIdx);
      fspec[maxIdx] = 0.0;
    }

  }

  if (nWaves.size() > 1) {
    sort(nWaves.begin(), nWaves.end());
  }
}

void Scantable::addAuxWaveNumbers(const int whichrow, const std::vector<int>& addNWaves, const std::vector<int>& rejectNWaves, std::vector<int>& nWaves)
{
  std::vector<int> tempAddNWaves, tempRejectNWaves;
  for (uInt i = 0; i < addNWaves.size(); ++i) {
    tempAddNWaves.push_back(addNWaves[i]);
  }
  if ((tempAddNWaves.size() == 2) && (tempAddNWaves[1] == -999)) {
    setWaveNumberListUptoNyquistFreq(whichrow, tempAddNWaves);
  }

  for (uInt i = 0; i < rejectNWaves.size(); ++i) {
    tempRejectNWaves.push_back(rejectNWaves[i]);
  }
  if ((tempRejectNWaves.size() == 2) && (tempRejectNWaves[1] == -999)) {
    setWaveNumberListUptoNyquistFreq(whichrow, tempRejectNWaves);
  }

  for (uInt i = 0; i < tempAddNWaves.size(); ++i) {
    bool found = false;
    for (uInt j = 0; j < nWaves.size(); ++j) {
      if (nWaves[j] == tempAddNWaves[i]) {
        found = true;
        break;
      }
    }
    if (!found) nWaves.push_back(tempAddNWaves[i]);
  }

  for (uInt i = 0; i < tempRejectNWaves.size(); ++i) {
    for (std::vector<int>::iterator j = nWaves.begin(); j != nWaves.end(); ) {
      if (*j == tempRejectNWaves[i]) {
        j = nWaves.erase(j);
      } else {
        ++j;
      }
    }
  }

  if (nWaves.size() > 1) {
    sort(nWaves.begin(), nWaves.end());
    unique(nWaves.begin(), nWaves.end());
  }
}

void Scantable::setWaveNumberListUptoNyquistFreq(const int whichrow, std::vector<int>& nWaves)
{
  if ((nWaves.size() == 2)&&(nWaves[1] == -999)) {
    int val = nWaves[0];
    int nyquistFreq = nchan(getIF(whichrow))/2+1;
    nWaves.clear();
    if (val > nyquistFreq) {  // for safety, at least nWaves contains a constant; CAS-3759
      nWaves.push_back(0);
    }
    while (val <= nyquistFreq) {
      nWaves.push_back(val);
      val++;
    }
  }
}

void Scantable::sinusoidBaseline(const std::vector<bool>& mask, const bool applyFFT, const std::string& fftMethod, const std::string& fftThresh, const std::vector<int>& addNWaves, const std::vector<int>& rejectNWaves, float thresClip, int nIterClip, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    //Fitter fitter = Fitter();
    //fitter.setExpression("sinusoid", nWaves);
    //fitter.setIterClipping(thresClip, nIterClip);

    int nRow = nrow();
    std::vector<bool> chanMask;
    std::vector<int> nWaves;

    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    for (int whichrow = 0; whichrow < nRow; ++whichrow) {
      chanMask = getCompositeChanMask(whichrow, mask);
      selectWaveNumbers(whichrow, chanMask, applyFFT, fftMethod, fftThresh, addNWaves, rejectNWaves, nWaves);

      //FOR DEBUGGING------------
      /*
      if (whichrow < 0) {// == nRow -1) {
        cout << "+++ i=" << setw(3) << whichrow << ", IF=" << setw(2) << getIF(whichrow);
        if (applyFFT) {
          cout << "[ ";
          for (uInt j = 0; j < nWaves.size(); ++j) {
            cout << nWaves[j] << ", ";
          }
          cout << " ]    " << endl;
        }
        cout << flush;
      }
      */
      //-------------------------

      //fitBaseline(chanMask, whichrow, fitter);
      //setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);
      std::vector<float> params;
      int nClipped = 0;
      std::vector<float> res = doSinusoidFitting(getSpectrum(whichrow), chanMask, nWaves, params, nClipped, thresClip, nIterClip, getResidual);
      setSpectrum(res, whichrow);
      //

      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "sinusoidBaseline()", params, nClipped);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }

    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

void Scantable::autoSinusoidBaseline(const std::vector<bool>& mask, const bool applyFFT, const std::string& fftMethod, const std::string& fftThresh, const std::vector<int>& addNWaves, const std::vector<int>& rejectNWaves, float thresClip, int nIterClip, const std::vector<int>& edge, float threshold, int chanAvgLimit, bool getResidual, const std::string& progressInfo, const bool outLogger, const std::string& blfile)
{
  try {
    ofstream ofs;
    String coordInfo = "";
    bool hasSameNchan = true;
    bool outTextFile = false;

    if (blfile != "") {
      ofs.open(blfile.c_str(), ios::out | ios::app);
      if (ofs) outTextFile = true;
    }

    if (outLogger || outTextFile) {
      coordInfo = getCoordInfo()[0];
      if (coordInfo == "") coordInfo = "channel";
      hasSameNchan = hasSameNchanOverIFs();
    }

    //Fitter fitter = Fitter();
    //fitter.setExpression("sinusoid", nWaves);
    //fitter.setIterClipping(thresClip, nIterClip);

    int nRow = nrow();
    std::vector<bool> chanMask;
    std::vector<int> nWaves;

    int minEdgeSize = getIFNos().size()*2;
    STLineFinder lineFinder = STLineFinder();
    lineFinder.setOptions(threshold, 3, chanAvgLimit);

    bool showProgress;
    int minNRow;
    parseProgressInfo(progressInfo, showProgress, minNRow);

    for (int whichrow = 0; whichrow < nRow; ++whichrow) {

      //-------------------------------------------------------
      //chanMask = getCompositeChanMask(whichrow, mask, edge, minEdgeSize, lineFinder);
      //-------------------------------------------------------
      int edgeSize = edge.size();
      std::vector<int> currentEdge;
      if (edgeSize >= 2) {
        int idx = 0;
        if (edgeSize > 2) {
          if (edgeSize < minEdgeSize) {
            throw(AipsError("Length of edge element info is less than that of IFs"));
          }
          idx = 2 * getIF(whichrow);
        }
        currentEdge.push_back(edge[idx]);
        currentEdge.push_back(edge[idx+1]);
      } else {
        throw(AipsError("Wrong length of edge element"));
      }
      lineFinder.setData(getSpectrum(whichrow));
      lineFinder.findLines(getCompositeChanMask(whichrow, mask), currentEdge, whichrow);
      chanMask = lineFinder.getMask();
      //-------------------------------------------------------

      selectWaveNumbers(whichrow, chanMask, applyFFT, fftMethod, fftThresh, addNWaves, rejectNWaves, nWaves);

      //fitBaseline(chanMask, whichrow, fitter);
      //setSpectrum((getResidual ? fitter.getResidual() : fitter.getFit()), whichrow);
      std::vector<float> params;
      int nClipped = 0;
      std::vector<float> res = doSinusoidFitting(getSpectrum(whichrow), chanMask, nWaves, params, nClipped, thresClip, nIterClip, getResidual);
      setSpectrum(res, whichrow);
      //

      outputFittingResult(outLogger, outTextFile, chanMask, whichrow, coordInfo, hasSameNchan, ofs, "autoSinusoidBaseline()", params, nClipped);
      showProgressOnTerminal(whichrow, nRow, showProgress, minNRow);
    }

    if (outTextFile) ofs.close();

  } catch (...) {
    throw;
  }
}

std::vector<float> Scantable::doSinusoidFitting(const std::vector<float>& data, const std::vector<bool>& mask, const std::vector<int>& waveNumbers, std::vector<float>& params, int& nClipped, float thresClip, int nIterClip, bool getResidual)
{
  if (data.size() != mask.size()) {
    throw(AipsError("data and mask sizes are not identical"));
  }
  if (data.size() < 2) {
    throw(AipsError("data size is too short"));
  }
  if (waveNumbers.size() == 0) {
    throw(AipsError("no wave numbers given"));
  }
  std::vector<int> nWaves;  // sorted and uniqued array of wave numbers
  nWaves.reserve(waveNumbers.size());
  copy(waveNumbers.begin(), waveNumbers.end(), back_inserter(nWaves));
  sort(nWaves.begin(), nWaves.end());
  std::vector<int>::iterator end_it = unique(nWaves.begin(), nWaves.end());
  nWaves.erase(end_it, nWaves.end());

  int minNWaves = nWaves[0];
  if (minNWaves < 0) {
    throw(AipsError("wave number must be positive or zero (i.e. constant)"));
  }
  bool hasConstantTerm = (minNWaves == 0);

  int nChan = data.size();
  std::vector<int> maskArray;
  std::vector<int> x;
  for (int i = 0; i < nChan; ++i) {
    maskArray.push_back(mask[i] ? 1 : 0);
    if (mask[i]) {
      x.push_back(i);
    }
  }

  int initNData = x.size();

  int nData = initNData;
  int nDOF = nWaves.size() * 2 - (hasConstantTerm ? 1 : 0);  //number of parameters to solve.

  const double PI = 6.0 * asin(0.5); // PI (= 3.141592653...)
  double baseXFactor = 2.0*PI/(double)(nChan-1);  //the denominator (nChan-1) should be changed to (xdata[nChan-1]-xdata[0]) for accepting x-values given in velocity or frequency when this function is moved to fitter. (2011/03/30 WK)

  // xArray : contains elemental values for computing the least-square matrix. 
  //          xArray.size() is nDOF and xArray[*].size() is nChan. 
  //          Each xArray element are as follows:
  //          xArray[0]    = {1.0, 1.0, 1.0, ..., 1.0}, 
  //          xArray[2n-1] = {sin(nPI/L*x[0]), sin(nPI/L*x[1]), ..., sin(nPI/L*x[nChan])}, 
  //          xArray[2n]   = {cos(nPI/L*x[0]), cos(nPI/L*x[1]), ..., cos(nPI/L*x[nChan])}, 
  //          where (1 <= n <= nMaxWavesInSW),
  //          or, 
  //          xArray[2n-1] = {sin(wn[n]PI/L*x[0]), sin(wn[n]PI/L*x[1]), ..., sin(wn[n]PI/L*x[nChan])}, 
  //          xArray[2n]   = {cos(wn[n]PI/L*x[0]), cos(wn[n]PI/L*x[1]), ..., cos(wn[n]PI/L*x[nChan])}, 
  //          where wn[n] denotes waveNumbers[n] (1 <= n <= waveNumbers.size()).
  std::vector<std::vector<double> > xArray;
  if (hasConstantTerm) {
    std::vector<double> xu;
    for (int j = 0; j < nChan; ++j) {
      xu.push_back(1.0);
    }
    xArray.push_back(xu);
  }
  for (uInt i = (hasConstantTerm ? 1 : 0); i < nWaves.size(); ++i) {
    double xFactor = baseXFactor*(double)nWaves[i];
    std::vector<double> xs, xc;
    xs.clear();
    xc.clear();
    for (int j = 0; j < nChan; ++j) {
      xs.push_back(sin(xFactor*(double)j));
      xc.push_back(cos(xFactor*(double)j));
    }
    xArray.push_back(xs);
    xArray.push_back(xc);
  }

  std::vector<double> z1, r1, residual;
  for (int i = 0; i < nChan; ++i) {
    z1.push_back((double)data[i]);
    r1.push_back(0.0);
    residual.push_back(0.0);
  }

  for (int nClip = 0; nClip < nIterClip+1; ++nClip) {
    // xMatrix : horizontal concatenation of 
    //           the least-sq. matrix (left) and an 
    //           identity matrix (right).
    // the right part is used to calculate the inverse matrix of the left part. 
    double xMatrix[nDOF][2*nDOF];
    double zMatrix[nDOF];
    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < 2*nDOF; ++j) {
        xMatrix[i][j] = 0.0;
      }
      xMatrix[i][nDOF+i] = 1.0;
      zMatrix[i] = 0.0;
    }

    int nUseData = 0;
    for (int k = 0; k < nChan; ++k) {
      if (maskArray[k] == 0) continue;

      for (int i = 0; i < nDOF; ++i) {
        for (int j = i; j < nDOF; ++j) {
          xMatrix[i][j] += xArray[i][k] * xArray[j][k];
        }
        zMatrix[i] += z1[k] * xArray[i][k];
      }

      nUseData++;
    }

    if (nUseData < 1) {
        throw(AipsError("all channels clipped or masked. can't execute fitting anymore."));      
    }

    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < i; ++j) {
        xMatrix[i][j] = xMatrix[j][i];
      }
    }

    std::vector<double> invDiag;
    for (int i = 0; i < nDOF; ++i) {
      invDiag.push_back(1.0/xMatrix[i][i]);
      for (int j = 0; j < nDOF; ++j) {
        xMatrix[i][j] *= invDiag[i];
      }
    }

    for (int k = 0; k < nDOF; ++k) {
      for (int i = 0; i < nDOF; ++i) {
        if (i != k) {
          double factor1 = xMatrix[k][k];
          double factor2 = xMatrix[i][k];
          for (int j = k; j < 2*nDOF; ++j) {
            xMatrix[i][j] *= factor1;
            xMatrix[i][j] -= xMatrix[k][j]*factor2;
            xMatrix[i][j] /= factor1;
          }
        }
      }
      double xDiag = xMatrix[k][k];
      for (int j = k; j < 2*nDOF; ++j) {
        xMatrix[k][j] /= xDiag;
      }
    }
    
    for (int i = 0; i < nDOF; ++i) {
      for (int j = 0; j < nDOF; ++j) {
        xMatrix[i][nDOF+j] *= invDiag[j];
      }
    }
    //compute a vector y which consists of the coefficients of the sinusoids forming the 
    //best-fit curves (a0,s1,c1,s2,c2,...), where a0 is constant and s* and c* are of sine 
    //and cosine functions, respectively. 
    std::vector<double> y;
    params.clear();
    for (int i = 0; i < nDOF; ++i) {
      y.push_back(0.0);
      for (int j = 0; j < nDOF; ++j) {
        y[i] += xMatrix[i][nDOF+j]*zMatrix[j];
      }
      params.push_back(y[i]);
    }

    for (int i = 0; i < nChan; ++i) {
      r1[i] = y[0];
      for (int j = 1; j < nDOF; ++j) {
        r1[i] += y[j]*xArray[j][i];
      }
      residual[i] = z1[i] - r1[i];
    }

    if ((nClip == nIterClip) || (thresClip <= 0.0)) {
      break;
    } else {
      double stdDev = 0.0;
      for (int i = 0; i < nChan; ++i) {
        stdDev += residual[i]*residual[i]*(double)maskArray[i];
      }
      stdDev = sqrt(stdDev/(double)nData);
      
      double thres = stdDev * thresClip;
      int newNData = 0;
      for (int i = 0; i < nChan; ++i) {
        if (abs(residual[i]) >= thres) {
          maskArray[i] = 0;
        }
        if (maskArray[i] > 0) {
          newNData++;
        }
      }
      if (newNData == nData) {
        break; //no more flag to add. iteration stops.
      } else {
        nData = newNData;
      }
    }
  }

  nClipped = initNData - nData;

  std::vector<float> result;
  if (getResidual) {
    for (int i = 0; i < nChan; ++i) {
      result.push_back((float)residual[i]);
    }
  } else {
    for (int i = 0; i < nChan; ++i) {
      result.push_back((float)r1[i]);
    }
  }

  return result;
}

void Scantable::fitBaseline(const std::vector<bool>& mask, int whichrow, Fitter& fitter)
{
  std::vector<double> dAbcissa = getAbcissa(whichrow);
  std::vector<float> abcissa;
  for (uInt i = 0; i < dAbcissa.size(); ++i) {
    abcissa.push_back((float)dAbcissa[i]);
  }
  std::vector<float> spec = getSpectrum(whichrow);

  fitter.setData(abcissa, spec, mask);
  fitter.lfit();
}

std::vector<bool> Scantable::getCompositeChanMask(int whichrow, const std::vector<bool>& inMask)
{
  std::vector<bool> mask = getMask(whichrow);
  uInt maskSize = mask.size();
  if (inMask.size() != 0) {
    if (maskSize != inMask.size()) {
      throw(AipsError("mask sizes are not the same."));
    }
    for (uInt i = 0; i < maskSize; ++i) {
      mask[i] = mask[i] && inMask[i];
    }
  }

  return mask;
}

/*
std::vector<bool> Scantable::getCompositeChanMask(int whichrow, const std::vector<bool>& inMask, const std::vector<int>& edge, const int minEdgeSize, STLineFinder& lineFinder)
{
  int edgeSize = edge.size();
  std::vector<int> currentEdge;
  if (edgeSize >= 2) {
      int idx = 0;
      if (edgeSize > 2) {
        if (edgeSize < minEdgeSize) {
          throw(AipsError("Length of edge element info is less than that of IFs"));
        }
        idx = 2 * getIF(whichrow);
      }
      currentEdge.push_back(edge[idx]);
      currentEdge.push_back(edge[idx+1]);
  } else {
    throw(AipsError("Wrong length of edge element"));
  }

  lineFinder.setData(getSpectrum(whichrow));
  lineFinder.findLines(getCompositeChanMask(whichrow, inMask), currentEdge, whichrow);

  return lineFinder.getMask();
}
*/

/* for poly. the variations of outputFittingResult() should be merged into one eventually (2011/3/10 WK)  */
void Scantable::outputFittingResult(bool outLogger, bool outTextFile, const std::vector<bool>& chanMask, int whichrow, const casa::String& coordInfo, bool hasSameNchan, ofstream& ofs, const casa::String& funcName, Fitter& fitter)
{
  if (outLogger || outTextFile) {
    std::vector<float> params = fitter.getParameters();
    std::vector<bool>  fixed  = fitter.getFixedParameters();
    float rms = getRms(chanMask, whichrow);
    String masklist = getMaskRangeList(chanMask, whichrow, coordInfo, hasSameNchan);

    if (outLogger) {
      LogIO ols(LogOrigin("Scantable", funcName, WHERE));
      ols << formatBaselineParams(params, fixed, rms, -1, masklist, whichrow, false) << LogIO::POST ;
    }
    if (outTextFile) {
      ofs << formatBaselineParams(params, fixed, rms, -1, masklist, whichrow, true) << flush;
    }
  }
}

/* for cspline. will be merged once cspline is available in fitter (2011/3/10 WK) */
void Scantable::outputFittingResult(bool outLogger, bool outTextFile, const std::vector<bool>& chanMask, int whichrow, const casa::String& coordInfo, bool hasSameNchan, ofstream& ofs, const casa::String& funcName, const std::vector<int>& edge, const std::vector<float>& params, const int nClipped)
{
  if (outLogger || outTextFile) {
    float rms = getRms(chanMask, whichrow);
    String masklist = getMaskRangeList(chanMask, whichrow, coordInfo, hasSameNchan);
    std::vector<bool> fixed;
    fixed.clear();

    if (outLogger) {
      LogIO ols(LogOrigin("Scantable", funcName, WHERE));
      ols << formatPiecewiseBaselineParams(edge, params, fixed, rms, nClipped, masklist, whichrow, false) << LogIO::POST ;
    }
    if (outTextFile) {
      ofs << formatPiecewiseBaselineParams(edge, params, fixed, rms, nClipped, masklist, whichrow, true) << flush;
    }
  }
}

/* for sinusoid. will be merged once sinusoid is available in fitter (2011/3/10 WK) */
void Scantable::outputFittingResult(bool outLogger, bool outTextFile, const std::vector<bool>& chanMask, int whichrow, const casa::String& coordInfo, bool hasSameNchan, ofstream& ofs, const casa::String& funcName, const std::vector<float>& params, const int nClipped)
{
  if (outLogger || outTextFile) {
    float rms = getRms(chanMask, whichrow);
    String masklist = getMaskRangeList(chanMask, whichrow, coordInfo, hasSameNchan);
    std::vector<bool> fixed;
    fixed.clear();

    if (outLogger) {
      LogIO ols(LogOrigin("Scantable", funcName, WHERE));
      ols << formatBaselineParams(params, fixed, rms, nClipped, masklist, whichrow, false) << LogIO::POST ;
    }
    if (outTextFile) {
      ofs << formatBaselineParams(params, fixed, rms, nClipped, masklist, whichrow, true) << flush;
    }
  }
}

void Scantable::parseProgressInfo(const std::string& progressInfo, bool& showProgress, int& minNRow)
{
  int idxDelimiter = progressInfo.find(",");
  if (idxDelimiter < 0) {
    throw(AipsError("wrong value in 'showprogress' parameter")) ;
  }
  showProgress = (progressInfo.substr(0, idxDelimiter) == "true");
  std::istringstream is(progressInfo.substr(idxDelimiter+1));
  is >> minNRow;
}

void Scantable::showProgressOnTerminal(const int nProcessed, const int nTotal, const bool showProgress, const int nTotalThreshold)
{
  if (showProgress && (nTotal >= nTotalThreshold)) {
    int nInterval = int(floor(double(nTotal)/100.0));
    if (nInterval == 0) nInterval++;

    if (nProcessed % nInterval == 0) {
      printf("\r");                          //go to the head of line
      printf("\x1b[31m\x1b[1m");             //set red color, highlighted
      printf("[%3d%%]", (int)(100.0*(double(nProcessed+1))/(double(nTotal))) );
      printf("\x1b[39m\x1b[0m");             //set default attributes
      fflush(NULL);
    }

    if (nProcessed == nTotal - 1) {
      printf("\r\x1b[K");                    //clear
      fflush(NULL);
    }

  }
}

std::vector<float> Scantable::execFFT(const int whichrow, const std::vector<bool>& inMask, bool getRealImag, bool getAmplitudeOnly)
{
  std::vector<bool>  mask = getMask(whichrow);

  if (inMask.size() > 0) {
    uInt maskSize = mask.size();
    if (maskSize != inMask.size()) {
      throw(AipsError("mask sizes are not the same."));
    }
    for (uInt i = 0; i < maskSize; ++i) {
      mask[i] = mask[i] && inMask[i];
    }
  }

  Vector<Float> spec = getSpectrum(whichrow);
  mathutil::doZeroOrderInterpolation(spec, mask);

  FFTServer<Float,Complex> ffts;
  Vector<Complex> fftres;
  ffts.fft0(fftres, spec);

  std::vector<float> res;
  float norm = float(2.0/double(spec.size()));

  if (getRealImag) {
    for (uInt i = 0; i < fftres.size(); ++i) {
      res.push_back(real(fftres[i])*norm);
      res.push_back(imag(fftres[i])*norm);
    }
  } else {
    for (uInt i = 0; i < fftres.size(); ++i) {
      res.push_back(abs(fftres[i])*norm);
      if (!getAmplitudeOnly) res.push_back(arg(fftres[i]));
    }
  }

  return res;
}


float Scantable::getRms(const std::vector<bool>& mask, int whichrow)
{
  Vector<Float> spec;
  specCol_.get(whichrow, spec);

  float mean = 0.0;
  float smean = 0.0;
  int n = 0;
  for (uInt i = 0; i < spec.nelements(); ++i) {
    if (mask[i]) {
      mean += spec[i];
      smean += spec[i]*spec[i];
      n++;
    }
  }

  mean /= (float)n;
  smean /= (float)n;

  return sqrt(smean - mean*mean);
}


std::string Scantable::formatBaselineParamsHeader(int whichrow, const std::string& masklist, bool verbose) const
{
  ostringstream oss;

  if (verbose) {
    oss <<  " Scan[" << getScan(whichrow)  << "]";
    oss <<  " Beam[" << getBeam(whichrow)  << "]";
    oss <<    " IF[" << getIF(whichrow)    << "]";
    oss <<   " Pol[" << getPol(whichrow)   << "]";
    oss << " Cycle[" << getCycle(whichrow) << "]: " << endl;
    oss << "Fitter range = " << masklist << endl;
    oss << "Baseline parameters" << endl;
    oss << flush;
  }

  return String(oss);
}

std::string Scantable::formatBaselineParamsFooter(float rms, int nClipped, bool verbose) const
{
  ostringstream oss;

  if (verbose) {
    oss << "Results of baseline fit" << endl;
    oss << "  rms = " << setprecision(6) << rms << endl;
    if (nClipped >= 0) {
      oss << "  Number of clipped channels = " << nClipped << endl;
    }
    for (int i = 0; i < 60; ++i) {
      oss << "-";
    }
    oss << endl;
    oss << flush;
  }

  return String(oss);
}

std::string Scantable::formatBaselineParams(const std::vector<float>& params, 
                                            const std::vector<bool>& fixed, 
                                            float rms, 
                                            int nClipped,
                                            const std::string& masklist, 
                                            int whichrow, 
                                            bool verbose, 
                                            int start, int count,
                                            bool resetparamid) const
{
  int nParam = (int)(params.size());

  if (nParam < 1) {
    return("  Not fitted");
  } else {

    ostringstream oss;
    oss << formatBaselineParamsHeader(whichrow, masklist, verbose);

    if (start < 0) start = 0;
    if (count < 0) count = nParam;
    int end = start + count;
    if (end > nParam) end = nParam;
    int paramidoffset = (resetparamid) ? (-start) : 0;

    for (int i = start; i < end; ++i) {
      if (i > start) {
        oss << ",";
      }
      std::string sFix = ((fixed.size() > 0) && (fixed[i]) && verbose) ? "(fixed)" : "";
      oss << "  p" << (i+paramidoffset) << sFix << "= " << right << setw(13) << setprecision(6) << params[i];
    }

    oss << endl;
    oss << formatBaselineParamsFooter(rms, nClipped, verbose);

    return String(oss);
  }

}

  std::string Scantable::formatPiecewiseBaselineParams(const std::vector<int>& ranges, const std::vector<float>& params, const std::vector<bool>& fixed, float rms, int nClipped, const std::string& masklist, int whichrow, bool verbose) const
{
  int nOutParam = (int)(params.size());
  int nPiece = (int)(ranges.size()) - 1;

  if (nOutParam < 1) {
    return("  Not fitted");
  } else if (nPiece < 0) {
    return formatBaselineParams(params, fixed, rms, nClipped, masklist, whichrow, verbose);
  } else if (nPiece < 1) {
    return("  Bad count of the piece edge info");
  } else if (nOutParam % nPiece != 0) {
    return("  Bad count of the output baseline parameters");
  } else {

    int nParam = nOutParam / nPiece;

    ostringstream oss;
    oss << formatBaselineParamsHeader(whichrow, masklist, verbose);

    stringstream ss;
    ss << ranges[nPiece] << flush;
    int wRange = ss.str().size() * 2 + 5;

    for (int i = 0; i < nPiece; ++i) {
      ss.str("");
      ss << "  [" << ranges[i] << "," << (ranges[i+1]-1) << "]";
      oss << left << setw(wRange) << ss.str();
      oss << formatBaselineParams(params, fixed, rms, 0, masklist, whichrow, false, i*nParam, nParam, true);
    }

    oss << formatBaselineParamsFooter(rms, nClipped, verbose);

    return String(oss);
  }

}

bool Scantable::hasSameNchanOverIFs()
{
  int nIF = nif(-1);
  int nCh;
  int totalPositiveNChan = 0;
  int nPositiveNChan = 0;

  for (int i = 0; i < nIF; ++i) {
    nCh = nchan(i);
    if (nCh > 0) {
      totalPositiveNChan += nCh;
      nPositiveNChan++;
    }
  }

  return (totalPositiveNChan == (nPositiveNChan * nchan(0)));
}

std::string Scantable::getMaskRangeList(const std::vector<bool>& mask, int whichrow, const casa::String& coordInfo, bool hasSameNchan, bool verbose)
{
  if (mask.size() <= 0) {
    throw(AipsError("The mask elements should be > 0"));
  }
  int IF = getIF(whichrow);
  if (mask.size() != (uInt)nchan(IF)) {
    throw(AipsError("Number of channels in scantable != number of mask elements"));
  }

  if (verbose) {
    LogIO logOs(LogOrigin("Scantable", "getMaskRangeList()", WHERE));
    logOs << LogIO::WARN << "The current mask window unit is " << coordInfo;
    if (!hasSameNchan) {
      logOs << endl << "This mask is only valid for IF=" << IF;
    }
    logOs << LogIO::POST;
  }

  std::vector<double> abcissa = getAbcissa(whichrow);
  std::vector<int> edge = getMaskEdgeIndices(mask);

  ostringstream oss;
  oss.setf(ios::fixed);
  oss << setprecision(1) << "[";
  for (uInt i = 0; i < edge.size(); i+=2) {
    if (i > 0) oss << ",";
    oss << "[" << (float)abcissa[edge[i]] << "," << (float)abcissa[edge[i+1]] << "]";
  }
  oss << "]" << flush;

  return String(oss);
}

std::vector<int> Scantable::getMaskEdgeIndices(const std::vector<bool>& mask)
{
  if (mask.size() <= 0) {
    throw(AipsError("The mask elements should be > 0"));
  }

  std::vector<int> out, startIndices, endIndices;
  int maskSize = mask.size();

  startIndices.clear();
  endIndices.clear();

  if (mask[0]) {
    startIndices.push_back(0);
  }
  for (int i = 1; i < maskSize; ++i) {
    if ((!mask[i-1]) && mask[i]) {
      startIndices.push_back(i);
    } else if (mask[i-1] && (!mask[i])) {
      endIndices.push_back(i-1);
    }
  }
  if (mask[maskSize-1]) {
    endIndices.push_back(maskSize-1);
  }

  if (startIndices.size() != endIndices.size()) {
    throw(AipsError("Inconsistent Mask Size: bad data?"));
  }
  for (uInt i = 0; i < startIndices.size(); ++i) {
    if (startIndices[i] > endIndices[i]) {
      throw(AipsError("Mask start index > mask end index"));
    }
  }

  out.clear();
  for (uInt i = 0; i < startIndices.size(); ++i) {
    out.push_back(startIndices[i]);
    out.push_back(endIndices[i]);
  }

  return out;
}

vector<float> Scantable::getTsysSpectrum( int whichrow ) const
{
  Vector<Float> tsys( tsysCol_(whichrow) ) ;
  vector<float> stlTsys ;
  tsys.tovector( stlTsys ) ;
  return stlTsys ;
}


}
//namespace asap