Index: trunk/psphot/doc/psfmodel.txt
===================================================================
--- trunk/psphot/doc/psfmodel.txt	(revision 9772)
+++ trunk/psphot/doc/psfmodel.txt	(revision 15000)
@@ -1,2 +1,31 @@
+
+2007.09.21
+
+  there are three places where we can choose to use errors in the fits or not:
+
+  * non-linear fitting of the models to the pixel flux distribution (poissonErrorsPhotLMM)
+  * linear fitting of the models to the pixel flux distribution (poissonErrorsPhotLin)
+  * fitting of the 2D variations in the psf parameters (poissonErrorsParams)
+  * fitting of the 2D variations in the aperture residuals
+
+2007.09.20
+
+  I am upgrading the PSF model to allow the parameter variation to be
+  modeled with pmTrend2D instead of just polynomials.  I am making a
+  list of places to modify the code:
+
+pmPSFAlloc : need a method beyong psfTrendMask to carry in the psf
+options
+
+pmPSF_ModelToFit : no need to change these
+
+update pmPSFBuildSimple to set the parameters of the pmTrend, which
+ever is used.
+
+pmPSFtry.c: some significant re-work!
+
+
+
+pmPSF_IO : need new functions to save / load the trend (psImages)
 
 2006.10.27