Changeset 532

Timestamp:

03/02/05 11:03:24 (20 years ago)

Author:

kil064

Message:

add Tsys weighting to average_pol

Location:

trunk

Files:

• python/scantable.py (modified) (1 diff)
• src/SDMath.cc (modified) (11 diffs)
• src/SDMath.h (modified) (1 diff)

trunk/python/scantable.py

@@ -988 +988 @@
                          averaging will be applied. The output will have all
                          specified points masked.
-            weight:      Weighting scheme. 'none' (default), or
-                         'var' (variance weighted)
+            weight:      Weighting scheme. 'none' (default), 'var' (1/var(spec)
+                         weighted), or 'tsys' (1/Tsys**2 weighted)
             insitu:      if False a new scantable is returned.
                          Otherwise, the scaling is done in-situ

trunk/src/SDMath.cc

@@ -813 +813 @@
 {
    WeightType wtType = NONE;
-   convertWeightString(wtType, weightStr, False);
-
-   const uInt nRows = in.nRow();
+   convertWeightString(wtType, weightStr, True);
 
 // Create output Table and reshape number of polarizations
@@ -824 +822 @@
   header.npol = 1;
   pTabOut->putSDHeader(header);
+//
+  const Table& tabIn = in.table();
 
 // Shape of input and output data 
@@ -834 +834 @@
   }
 //
+  const uInt nRows = in.nRow();
   const uInt nChan = shapeIn(asap::ChanAxis);
+  AlwaysAssert(asap::nAxes==4,AipsError);
   const IPosition vecShapeOut(4,1,1,1,nChan);     // A multi-dim form of a Vector shape
   IPosition start(4), end(4);
@@ -843 +845 @@
   Array<Bool> outMask(shapeOut, True);
   const IPosition axes(2, asap::PolAxis, asap::ChanAxis);              // pol-channel plane
+
+// Attach Tsys column if needed
+
+  ROArrayColumn<Float> tSysCol;
+  Array<Float> tSys;
+  if (wtType==TSYS) {
+     tSysCol.attach(tabIn,"TSYS");
+  }
 // 
   const Bool useMask = (mask.nelements() == shapeIn(asap::ChanAxis));
@@ -855 +865 @@
       Array<Float>& arr = marr.getRWArray();
       const Array<Bool>& barr = marr.getMask();
+      
+// Get Tsys
+
+      if (wtType==TSYS) {
+         tSysCol.get(iRow,tSys);
+      }
 
 // Make iterators to iterate by pol-channel planes
+// The tSys array is empty unless wtType=TSYS so only
+// access the iterator is that is the case
 
       ReadOnlyArrayIterator<Float> itDataPlane(arr, axes);
       ReadOnlyArrayIterator<Bool> itMaskPlane(barr, axes);
+      ReadOnlyArrayIterator<Float>* pItTsysPlane = 0;
+      if (wtType==TSYS) pItTsysPlane = new ReadOnlyArrayIterator<Float>(tSys, axes);
 
 // Accumulations
@@ -874 +894 @@
         Vector<Float> t1(nChan); t1 = 0.0;
         Vector<Bool> t2(nChan); t2 = True;
+        Float tSys = 0.0;
         MaskedArray<Float> vecSum(t1,t2);
         Float norm = 0.0;
@@ -879 +900 @@
            ReadOnlyVectorIterator<Float> itDataVec(itDataPlane.array(), 1);
            ReadOnlyVectorIterator<Bool> itMaskVec(itMaskPlane.array(), 1);
+//
+           ReadOnlyVectorIterator<Float>* pItTsysVec = 0;
+           if (wtType==TSYS) {
+              pItTsysVec = new ReadOnlyVectorIterator<Float>(pItTsysPlane->array(), 1);
+           }             
+//
            while (!itDataVec.pastEnd()) {     
 
@@ -885 +912 @@
               if (useMask) {
                  const MaskedArray<Float> spec(itDataVec.vector(),mask&&itMaskVec.vector());
-                 if (wtType==VAR) fac = 1.0 / variance(spec);
+                 if (wtType==VAR) {
+                    fac = 1.0 / variance(spec);
+                 } else if (wtType==TSYS) {
+                    tSys = pItTsysVec->vector()[0];      // Drop pseudo channel dependency
+                    fac = 1.0 / tSys / tSys;
+                 }                    
               } else {
                  const MaskedArray<Float> spec(itDataVec.vector(),itMaskVec.vector());
-                 if (wtType==VAR) fac = 1.0 / variance(spec);
+                 if (wtType==VAR) {
+                    fac = 1.0 / variance(spec);
+                 } else if (wtType==TSYS) {
+                    tSys = pItTsysVec->vector()[0];      // Drop pseudo channel dependency
+                    fac = 1.0 / tSys / tSys;
+                 }
               }
 
@@ -901 +938 @@
               itDataVec.next();
               itMaskVec.next();
+              if (wtType==TSYS) pItTsysVec->next();
            }
+           
+// Clean up
+
+           if (pItTsysVec) {
+              delete pItTsysVec; 
+              pItTsysVec = 0;
+           }            
         }
 
@@ -926 +971 @@
         itDataPlane.next();
         itMaskPlane.next();
+        if (wtType==TSYS) pItTsysPlane->next();
       }
 
@@ -935 +981 @@
       putDataInSDC(sc, outData, outMask);
       pTabOut->putSDContainer(sc);
+//
+      if (wtType==TSYS) {
+         delete pItTsysPlane;
+         pItTsysPlane = 0;
+      }
    }
 

trunk/src/SDMath.h

@@ -121 +121 @@
                             casa::Bool doAll, casa::uInt what, casa::Bool tSys) const;
 
-// Average polarizations
+// Average polarizations.
    SDMemTable* averagePol(const SDMemTable& in, const casa::Vector<casa::Bool>& mask,
                           const casa::String& wtStr) const;