Changeset 2363

Timestamp:

12/07/11 17:05:24 (13 years ago)

Author:

Takeshi Nakazato

Message:

New Development: No

JIRA Issue: Yes CAS-2816

Ready for Test: No

Interface Changes: Yes/No

What Interface Changed: Please list interface changes

Test Programs: List test programs

Put in Release Notes: Yes/No

Module(s): Module Names change impacts.

Description: Describe your changes here...

For Gaussian kernel, user-specified kernel width is treated as HWHM,
and convolution support is set to 4*HWHM.

Location:

trunk

Files:

• python/asapgrid.py (modified) (1 diff)
• src/STGrid.cpp (modified) (2 diffs)

trunk/python/asapgrid.py

@@ -22 +22 @@
         self.gridder._defineimage( nx, ny, cellx, celly, center )
 
-    def setOption( self, convType='box', convSupport=-1 ):
-        self.gridder._setoption( convType, convSupport )
+    def setOption( self, convType='box', width=-1 ):
+        self.gridder._setoption( convType, width )
 
     def setWeight( self, weightType='uniform' ):

trunk/src/STGrid.cpp

@@ -623 +623 @@
 {
   convFunc = 0.0 ;
-  for ( Int i = 0 ; i < convSampling_*convSupport_ ; i++ ) {
-    Double hwhm = convSampling_ * convSupport_ * 0.25 ;
+  // HWHM of the Gaussian is convSupport_ / 4
+  // To take into account Gaussian tail, kernel cutoff is set to 4 * HWHM
+  Int len = convSampling_ * convSupport_ ;
+  Double hwhm = len * 0.25 ;
+  for ( Int i = 0 ; i < len ; i++ ) {
     Double val = Double(i) / hwhm ;
     convFunc(i) = exp( -log(2)*val*val ) ;
@@ -653 +656 @@
   }
   else if ( convType_ == "GAUSS" ) {
+    // to take into account Gaussian tail
     if ( convSupport_ < 0 )
-      convSupport_ = 3 ;
+      convSupport_ = 12 ; // 3 * 4
+    else {
+      convSupport_ = userSupport_ * 4 ;
+    }
     Int convSize = convSampling_ * ( 2 * convSupport_ + 2 ) ;
     convFunc.resize( convSize ) ;