Changeset 9770 for trunk/psModules/src/objects/pmPSFtry.c

Timestamp:

Oct 28, 2006, 10:23:51 AM (20 years ago)

Author:

magnier

Message:

This is an important change to the PSF shape model.

• I have changed the definition of the elliptical contour parameters

(PM_PAR_SXX,SYY are now sigma_x,y/sqrt(2), rather than
sqrt(2)/sigma_x.

• I have changed the way in which the SXY term is modelled. rather

than fit SXY to a polynomial, I now fit SXY / (1/SXX^{2 + 1/SYY}2)^{2.
this representation is more likely to be well-described by a
polynomial. the other form is likely to vary as xy/r}N rather than xy
r^N.

these changes imply that the models all need to treat the SXX,SYY,SXY
terms in the same fashion (ie, fitting a contour of the form (x/SXX)<sup>2
+ (y/SYY)</sup>2 + SXY*x*y). If an arbitrary model uses some other meaning
for SXX, SYY, SXY, then it will have to define its own exceptions in
the functions pmPSFFromModels and pmModelFromPSF (the latter has an
implementation for each model already).

• I have cleaned up the pmModel_NAME.c functions to use the #define names

for the parameters (PM_PAR_XXX) everywhere, and to use #def names for
the functions. this latter change makes it easy to specify the model
function names in a single location.

File:

• trunk/psModules/src/objects/pmPSFtry.c (modified) (2 diffs)

trunk/psModules/src/objects/pmPSFtry.c

@@ -5 +5 @@
  *  @author EAM, IfA
  *
- *  @version $Revision: 1.21 $ $Name: not supported by cvs2svn $
- *  @date $Date: 2006-10-24 22:55:05 $
+ *  @version $Revision: 1.22 $ $Name: not supported by cvs2svn $
+ *  @date $Date: 2006-10-28 20:23:51 $
  *
  *  Copyright 2004 Maui High Performance Computing Center, University of Hawaii
@@ -111 +111 @@
         pmSource *source = psfTry->sources->data[i];
         pmModel  *model  = pmSourceModelGuess (source, psfTry->psf->type);
+        if (model == NULL) {
+            psError(PS_ERR_UNKNOWN, false, "failed to build model");
+            return NULL;
+        }
         x = source->peak->x;
         y = source->peak->y;