Changeset 343

Timestamp:

02/01/05 13:21:27 (20 years ago)

Author:

vor010

Message:

SDLineFinder - now algorithm does many iterations
to ensure that weak lines, which are close to the strong ones, are also found

Location:

trunk/src

Files:

• SDLineFinder.cc (modified) (7 diffs)
• SDLineFinder.h (modified) (1 diff)

trunk/src/SDLineFinder.cc

@@ -35 +35 @@
 
 // STL
+#include <functional>
+#include <algorithm>
 #include <iostream>
 
@@ -41 +43 @@
 using namespace std;
 using namespace boost::python;
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// LFRunningMean - a running mean algorithm for line detection
+//
+//
 
 namespace asap {
@@ -117 +125 @@
 } // namespace asap
 
+//
+///////////////////////////////////////////////////////////////////////////////
+
+
 ///////////////////////////////////////////////////////////////////////////////
 //
@@ -280 +292 @@
 ///////////////////////////////////////////////////////////////////////////////
 
-
+///////////////////////////////////////////////////////////////////////////////
+//
+// SDLineFinder::IntersectsWith  -  An auxiliary object function to test
+// whether two lines have a non-void intersection
+//
+
+
+// line1 - range of the first line: start channel and stop+1
+SDLineFinder::IntersectsWith::IntersectsWith(const std::pair<int,int> &in_line1) :
+                          line1(in_line1) {}
+
+
+// return true if line2 intersects with line1 with at least one
+// common channel, and false otherwise
+// line2 - range of the second line: start channel and stop+1
+bool SDLineFinder::IntersectsWith::operator()(const std::pair<int,int> &line2)
+                          const throw()
+{
+  if (line2.second<line1.first) return false; // line2 is at lower channels
+  if (line2.first>line1.second) return false; // line2 is at upper channels
+  return true; // line2 has an intersection or is adjacent to line1
+}
+
+//
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// SDLineFinder::BuildUnion - An auxiliary object function to build a union
+// of several lines to account for a possibility of merging the nearby lines
+//
+
+// set an initial line (can be a first line in the sequence)
+SDLineFinder::BuildUnion::BuildUnion(const std::pair<int,int> &line1) :
+                             temp_line(line1) {}
+
+// update temp_line with a union of temp_line and new_line
+// provided there is no gap between the lines
+void SDLineFinder::BuildUnion::operator()(const std::pair<int,int> &new_line)
+                                   throw()
+{
+  if (new_line.first<temp_line.first) temp_line.first=new_line.first;
+  if (new_line.second>temp_line.second) temp_line.second=new_line.second;
+}
+
+// return the result (temp_line)
+const std::pair<int,int>& SDLineFinder::BuildUnion::result() const throw()
+{
+  return temp_line;
+}
+
+//
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// SDLineFinder::LaterThan - An auxiliary object function to test whether a
+// specified line is at lower spectral channels (to preserve the order in
+// the line list)
+//
+
+// setup the line to compare with
+SDLineFinder::LaterThan::LaterThan(const std::pair<int,int> &in_line1) :
+                         line1(in_line1) {}
+
+// return true if line2 should be placed later than line1
+// in the ordered list (so, it is at greater channel numbers)
+bool SDLineFinder::LaterThan::operator()(const std::pair<int,int> &line2)
+                          const throw()
+{
+  if (line2.second<line1.first) return false; // line2 is at lower channels
+  if (line2.first>line1.second) return true; // line2 is at upper channels
+  
+  // line2 intersects with line1. We should have no such situation in
+  // practice
+  return line2.first>line1.first;
+}
+
+//
+///////////////////////////////////////////////////////////////////////////////
+
+
+///////////////////////////////////////////////////////////////////////////////
+//
 // SDLineFinder  -  a class for automated spectral line search
+//
+//
 
 SDLineFinder::SDLineFinder() throw() : edge(0,0)
@@ -371 +468 @@
   lines.resize(0); // search from the scratch
   Vector<Bool> temp_mask(mask);
-  size_t cursz;
-  do {
-     cursz=lines.size();
+  Bool need2iterate=True;
+  while (need2iterate) {
      // line find algorithm
-     LFRunningMean lfalg(spectrum,temp_mask,edge,max_box_nchan,min_nchan,threshold);
-     lfalg.findLines(lines);
+     LFRunningMean lfalg(spectrum,temp_mask,edge,max_box_nchan,min_nchan,
+                         threshold);
+     std::list<pair<int,int> > new_lines;
+     lfalg.findLines(new_lines);
+     if (!new_lines.size()) need2iterate=False;
      temp_mask=getMask();
-  } while (cursz!=lines.size());
+     // update the list (lines) merging intervals, if necessary
+     addNewSearchResult(new_lines);
+  }
   return int(lines.size());
 }
@@ -474 +575 @@
       for (std::list<pair<int,int> >::const_iterator cli=newlines.begin();
            cli!=newlines.end();++cli) {
-           // search for a right place for the new line
-           //TODO
+           
+           // the first item, which has a non-void intersection or touches
+           // the new line
+           std::list<pair<int,int> >::iterator pos_beg=find_if(lines.begin(),
+                          lines.end(), IntersectsWith(*cli));           
+           // the last such item          
+           std::list<pair<int,int> >::iterator pos_end=find_if(pos_beg,
+                          lines.end(), not1(IntersectsWith(*cli)));
+
+           // extract all lines which intersect or touch a new one into
+           // a temporary buffer. This may invalidate the iterators
+           // line_buffer may be empty, if no lines intersects with a new
+           // one.
+           std::list<pair<int,int> > lines_buffer;
+           lines_buffer.splice(lines_buffer.end(),lines, pos_beg, pos_end);
+
+           // build a union of all intersecting lines 
+           pair<int,int> union_line=for_each(lines_buffer.begin(),
+                   lines_buffer.end(),BuildUnion(*cli)).result();
+           
+           // search for a right place for the new line (union_line) and add
+           std::list<pair<int,int> >::iterator pos2insert=find_if(lines.begin(),
+                          lines.end(), LaterThan(union_line));
+           lines.insert(pos2insert,union_line);
       }
   }
@@ -484 +607 @@
       throw AipsError(String("SDLineFinder::addNewSearchResult - STL error: ")+ex.what());
   }
-
-}
+}

trunk/src/SDLineFinder.h

@@ -87 +87 @@
 protected:
    // concatenate two lists preserving the order. If two lines appear to
-   // be adjacent, they are joined into the new one
+   // be adjacent or have a non-void intersection, they are joined into 
+   // the new line
    void addNewSearchResult(const std::list<std::pair<int, int> > &newlines)
                            throw(casa::AipsError);
+                           
+   // An auxiliary object function to test whether two lines have a non-void
+   // intersection
+   class IntersectsWith : public std::unary_function<pair<int,int>, bool> {
+       std::pair<int,int> line1;           // range of the first line
+                                           // start channel and stop+1
+   public:
+        IntersectsWith(const std::pair<int,int> &in_line1);
+        // return true if line2 intersects with line1 with at least one
+        // common channel, and false otherwise
+        bool operator()(const std::pair<int,int> &line2) const throw();
+   };
+
+   // An auxiliary object function to build a union of several lines
+   // to account for a possibility of merging the nearby lines
+   class BuildUnion {
+       std::pair<int,int> temp_line;       // range of the first line
+                                           // start channel and stop+1
+   public:
+        BuildUnion(const std::pair<int,int> &line1);
+        // update temp_line with a union of temp_line and new_line
+        // provided there is no gap between the lines
+        void operator()(const std::pair<int,int> &new_line) throw();
+        // return the result (temp_line)
+        const std::pair<int,int>& result() const throw();
+   };
+   
+   // An auxiliary object function to test whether a specified line
+   // is at lower spectral channels (to preserve the order in the line list)
+   class LaterThan : public std::unary_function<pair<int,int>, bool> {
+       std::pair<int,int> line1;           // range of the first line
+                                           // start channel and stop+1
+   public:
+        LaterThan(const std::pair<int,int> &in_line1);
+
+        // return true if line2 should be placed later than line1
+        // in the ordered list (so, it is at greater channel numbers)
+        bool operator()(const std::pair<int,int> &line2) const throw();
+   }; 
+   
 private:
    casa::CountedConstPtr<SDMemTable> scan; // the scan to work with