Changeset 28906

Timestamp:

Aug 12, 2010, 9:28:25 AM (16 years ago)

Author:

eugene

Message:

add notes

File:

• branches/eam_branches/ipp-20100621/psphot/doc/notes.20100715.txt (modified) (2 diffs)

branches/eam_branches/ipp-20100621/psphot/doc/notes.20100715.txt

@@ +1 @@
+
+2010.08.12
+
+  speeding up the PCM fitting.  
+
+  * first, I need to convert the convolutions to FFTs (double check that this will actually be faster!)
+  * second, I need to thread the PCM fitting process
+
+  I have three options:
+
+  1) use the FFT threading in fftw -- each convolution would run threaded, but separate ones would be run in series
+     * con: the images are generally small, so the threading overhead may be large compared to the operation (test?)
+  2) each pass of the minimization has 1 + N convolutions to perform: run these in separate threads
+     * can only use 1+N threads, where N is the number of free parameters (Io, Sxx, Syy, Sxy, but maybe also Xo, Yo)
+  3) thread by source, using the system defined for the other fitting. 
+     * since these source are large, this is a bit trickier to guarantee non-collision. 
+     + infrastructure is easy -- copy psphotBlendFit.
 
 2010.07.15
@@ -8 +25 @@
 * psphot forced fails for negative flux
   - do a run, plot a histogram of fluxes as various steps
+  FIXED: this was caused by minimum limit of 0.0 in linear fitting
 
 * capability to choose extended source fits based on |b|
+
 * update psf-convolved fitting to work with sersic (iteration)
+  DONE: but, needs to be sped up
+