Changeset 430

Timestamp:

02/14/05 17:34:45 (20 years ago)

Author:

kil064

Message:

add function getCircularSepctrum
fix bug in getSTokesSPectrum where beamSel and IFSel were ignored

Location:

trunk/src

Files:

• SDMemTable.cc (modified) (6 diffs)
• SDMemTable.h (modified) (2 diffs)

trunk/src/SDMemTable.cc

@@ -340 +340 @@
 std::vector<float> SDMemTable::getSpectrum(Int whichRow) const 
 {
+
   Array<Float> arr;
   specCol_.get(whichRow, arr);
-//
   return getFloatSpectrum (arr);
 }
@@ -353 +353 @@
 //
 {
+  AlwaysAssert(asap::nAxes==4,AipsError);
   if (nPol()!=1 && nPol()!=2 && nPol()!=4) {
      throw (AipsError("You must have 1,2 or 4 polarizations to get the Stokes parameters"));
@@ -359 +360 @@
   stokesCol_.get(whichRow, arr);
 //
-  if (doPol && (polSel_==1 || polSel_==2)) {
+  if (doPol && (polSel_==1 || polSel_==2)) {       //   Q,U --> P, P.A.
+
+// Set current cursor location
+
      const IPosition& shape = arr.shape();
-     IPosition start(asap::nAxes,0);
-     IPosition end(shape-1);
-//
-     start(asap::PolAxis) = 1;                       // Q
-     end (asap::PolAxis) = 1;
-     Array<Float> Q = arr(start,end);
-//
-     start(asap::PolAxis) = 2;                       // U
-     end (asap::PolAxis) = 2;
-     Array<Float> U = arr(start,end);
-//
+     IPosition start, end;
+     setCursorSlice (start, end, shape);
+
+// Get Q and U slices
+
+     Array<Float> Q = SDPolUtil::getStokesSlice (arr,start,end,"Q");
+     Array<Float> U = SDPolUtil::getStokesSlice (arr,start,end,"U");
+
+// Compute output 
+
      Array<Float> out;
      if (polSel_==1) {                                        // P
@@ -378 +381 @@
         out = SDPolUtil::positionAngle(Q,U) + paOffset;
      }
-//
+
+// Copy to output
+
      IPosition vecShape(1,shape(asap::ChanAxis));
      Vector<Float> outV = out.reform(vecShape);
-     std::vector<float> spectrum(out.nelements());
-     for (uInt i=0; i<out.nelements(); i++) {
-        spectrum[i] = outV[i];
-     }
-     return spectrum;
+     return convertVector(outV);
   } else {
-     return getFloatSpectrum (arr);
-  }
+
+// Selects at the cursor location
+
+    return getFloatSpectrum (arr);
+  }
+}
+
+std::vector<float> SDMemTable::getCircularSpectrum(Int whichRow, Bool doRR) const 
+//
+// Gets
+//  RR = I + V
+//  LL = I - V
+//
+{
+  AlwaysAssert(asap::nAxes==4,AipsError);
+  if (nPol()!=4) {
+     throw (AipsError("You must have 4 polarizations to get RR or LL"));
+  }
+  Array<Float> arr;
+  stokesCol_.get(whichRow, arr);
+
+// Set current cursor location
+
+  const IPosition& shape = arr.shape();
+  IPosition start, end;
+  setCursorSlice (start, end, shape);
+
+// Get I and V slices
+
+  Array<Float> I = SDPolUtil::getStokesSlice (arr,start,end,"I");
+  Array<Float> V = SDPolUtil::getStokesSlice (arr,start,end,"V");
+
+// Compute output 
+
+  Array<Float> out = SDPolUtil::circularPolarizationFromStokes (I, V, doRR);
+
+// Copy to output
+
+  IPosition vecShape(1,shape(asap::ChanAxis));
+  Vector<Float> outV = out.reform(vecShape);
+  return convertVector(outV);
 }
 
 std::vector<float> SDMemTable::getFloatSpectrum (const Array<Float>& arr) const
+//
+// Get spectrum at cursor location
+//
 {
 
@@ -1568 +1611 @@
 //
 // phase in degrees
+// Applies to all Beams and IFs
+// Might want to optionally select on Beam/IF
 //
 {
@@ -1602 +1647 @@
    }
 }
+
+
+void SDMemTable::setCursorSlice (IPosition& start, IPosition& end,
+                                 const IPosition& shape) const
+{
+   const uInt nDim = shape.nelements();
+   start.resize(nDim);
+   end.resize(nDim);
+//
+   start(asap::BeamAxis) = beamSel_;
+   end(asap::BeamAxis) = beamSel_;
+//
+   start(asap::IFAxis) = IFSel_;
+   end(asap::IFAxis) = IFSel_;
+//
+   start(asap::PolAxis) = polSel_;
+   end(asap::PolAxis) = polSel_;
+//
+   start(asap::ChanAxis) = 0;
+   end(asap::ChanAxis) = shape(asap::ChanAxis) - 1;
+}
+
+
+std::vector<float> SDMemTable::convertVector (const Vector<Float>& in) const
+{
+   std::vector<float> out(in.nelements());
+   for (uInt i=0; i<in.nelements(); i++) {
+      out[i] = in[i];
+   }
+   return out;
+}
+

trunk/src/SDMemTable.h

@@ -94 +94 @@
   virtual std::vector<float> getSpectrum(casa::Int whichRow=0) const;
   virtual std::vector<bool> getMask(casa::Int whichRow=0) const;
-  // Get STokes at cursor location. One of either I,Q,U,V or I,P,PA,V (doPol=True)
+
+
+  // When we can handle input correlations being either circular or
+  // linear, we should probably have functions; getLinear, getCircular, getStokes
+  // since one can inter-convert between all three regardless of the input
+  // provided there are 4 polarizations. For now, we are assuming, if
+  // there are 4 polarizations, that we have linears.  getSpectrum 
+  // is then 'getLinear', getStokesSpectrum is 'getStokes' and getCircularSpectrum
+  // is 'getCircular'  
+
+
+  // Get Stokes at cursor location. One of either I,Q,U,V or I,P,PA,V (doPol=True)
   // If the latter, you can add a PA offset (degrees)
   virtual std::vector<float> getStokesSpectrum(casa::Int whichRow=0, 
                                                casa::Bool doPol=casa::False,
                                                casa::Float paOffset=0.0) const;
+
+  // Get RR or LL at cursor location (not polSel_)
+  virtual std::vector<float> getCircularSpectrum(casa::Int whichRow=0, 
+                                                 casa::Bool rr=casa::True) const;
 
   virtual casa::Float getTsys(casa::Int whichRow=0) const;
@@ -238 +253 @@
   void attach();
   void renumber();
+
+  // Generate start and end for shape and current cursor selection
+  void setCursorSlice(casa::IPosition& start, casa::IPosition& end, const casa::IPosition& shape) const;
+
+  // Convert Vector to vector
+  std::vector<float> convertVector (const casa::Vector<casa::Float>& in) const;
+
+
   // the current cursor into the array
   casa::Int IFSel_,beamSel_,polSel_;