Running Issue on SEctractor

Question

I got this bug while running SExtractor

`----- SExtractor 2.28.0 started on 2023-12-04 at 16:30:12 with 1 thread

Reading Neural Network Weights Error: SOM file not found: default.som

`

But I didn't have this bug before, I just ran again the same fits. How can I solve this problem? thanks.

I rewrite the default.sex. But I copy the fits to another folder and another default.sex files, and it works. I have no idea where the bug come from.

Answer 1

Are you sure it's the default.som file that you want/need ? This is marked 'Experimental' and only appears in the config file if you generate the extended version of the config file using sex -dd:

#--------------------------- Experimental Stuff -----------------------------

PSF_NAME         default.psf    # File containing the PSF model
PSF_NMAX         1              # Max.number of PSFs fitted simultaneously
PATTERN_TYPE     RINGS-HARMONIC # can RINGS-QUADPOLE, RINGS-OCTOPOLE,
                                # RINGS-HARMONICS or GAUSS-LAGUERRE
SOM_NAME         default.som    # File containing Self-Organizing Map weights

I can't find the file in the github repository either even though there is a som.c and som.h that would use it. The file that is more normally used is the default.nnw file which is used for the Star/Galaxy separation:

#------------------------- Star/Galaxy Separation ----------------------------
 
SEEING_FWHM      1.2            # stellar FWHM in arcsec
STARNNW_NAME     default.nnw    # Neural-Network_Weight table filename

The output in your question also talks about the "Neural Network Weights" which makes me think that it's this file that you actually want. It should be included in the distribution for SExtractor but you could get it from github if needed. The other config files referenced in the default.sex namely default.param, default.conv, default.nnw, need to be in the same directory (or you need to modify the references in the default.sex to include the full path to the file). I would also comment out the reference to the SOM_NAME variable and the default.som file as they don't seem to be ready for prime time.