SExtractor 2.5.0 released

[Emmanuel Bertin]

The latest version is now available on SExtractor's webpage. It includes the following bug fixes:

• compilation problems with gcc 4.1+.
• pb with local background estimates
• issue with conflicting CDi_j/CDELTi parameters
• overflow with very large command lines
  

and the following improvements (among others):

• support for TNX distorsions
• simplified support for ICRS
• new CATALOG_TYPE ASCII_VOTABLE
• new WRITE_XML option to dump a VOTable-compliant meta-data file
  

The VOTable stuff is the most important change made to this version. I started out from the "AVOCat" VOTable implementation done in SExtractor by G.Tissier in 2004 in the framework of the Euro-VO and built from there. Using the CATALOG_TYPE ASCII_VOTABLE one can now write VOTable-compliant XML catalogs (or even stream them if CATALOG_NAME is set to STDOUT !). VOTables can be manipulated with tools such as TOPCAT.
Warnings and Fatal error messages are also logged. For any CATALOG_TYPE, meta-data can be written to a separated XML-VOTable file using WRITE_XML Y together with warning and error messages.
Sorry for all the suggestions and bug fixes that could not make it for this release.
I will now concentrate on SWarp and SCAMP. Have fun!
Emmanuel.

[Henry Joy McCracken]

Dear Emmanuel,

Thanks for the new release of sextractor.

We compiled the latest version of sextractor here on a power mac g5.

Unfortunately sextractor now crashes during catalogue extraction of several large images. The previous version didn't produce any problems. Please find included below the gdb backtrace, as well as the configuration log.

cheers
henry

(gdb) run ch1/mosaic_ch1_forsex.fits -c ch1_sex.conf  -CATALOG_NAME ch1/ch1.cat -WEIGHT_IMAGE ch1/weight_ch1_forsex.fits
Starting program: /usr/local/bin/sex ch1/mosaic_ch1_forsex.fits -c ch1_sex.conf  -CATALOG_NAME ch1/ch1.cat -WEIGHT_IMAGE ch1/weight_ch1_forsex.fits
Reading symbols for shared libraries . done
----- SExtractor 2.5.0 started on 2006-07-18 at 11:32:11 with 1 thread

Measuring from: "Unnamed"  / 10857 x 11088 / 32 bits FLOATING POINT data
Weighting from: "Unnamed"  / 10857 x 11088 / 32 bits FLOATING POINT data
(M+D) Background: 0.947012   RMS: 0.0281577  / Threshold: 0.0281577
> Line:  976  Objects:     7189 detected /     3530 sextracted

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x007f5000
backguess (bkg=0xa6cf0, mean=0xbfffef58, sigma=0x18ca104) at back.c:638
638           sum += (pix = *(histot++));
(gdb) where
#0  backguess (bkg=0xa6cf0, mean=0xbfffef58, sigma=0x18ca104) at back.c:638
#1  0x0000d4e0 in localback (field=0x1806c00, obj=0x18ca000) at back.c:886
#2  0x00002d8c in analyse (field=0x1806c00, dfield=0x0, objnb=2049, objlist=0xbffff050) at analyse.c:58
#3  0x00033b58 in sortit (field=0x1806c00, dfield=0x0, wfield=0x180a400, dwfield=0x180a400, info=0x0, objlist=0xbffff110, cdwscan=0xfff, wscan=0x7f300c) at scan.c:718
#4  0x00032ad8 in scanimage (field=0x1806c00, dfield=0x0, pffield=0xbffff2a0, nffield=0, wfield=0x180a400, dwfield=0x0) at scan.c:448
#5  0x0001b560 in makeit () at makeit.c:359
#6  0x0001a4dc in main (argc=8, argv=0xbffff478) at main.c:121

[Henry Joy McCracken]

Dear Emmanuel,

When we run sextractor with BACKPHOTO_TYPE GLOBAL, the extraction completes without error. So, as suggested by the gdb trace, the segfault comes from the estimation of the local background. Perhaps this problem was introduced as part of the 'bugfix' for this release?

many thanks,
cheers
henry

[Emmanuel Bertin]

Yes probably a side-effect of the latest bugfixes . I cannot reproduce it on my PC linux box though. Do you see a crash on any image, or only this one? In the second case, you might want to send me your image so that I can make tests. In any case could you PM me your configuration files? Thanks.
Cheers,
Emmanuel.

[jaron_kurk]

Are older versions of SExtractor still available? I am looking for version 2.3.2 (Linux build). Thanks, Jaron.

[Henry Joy McCracken]

hi jaron,

did you try in the usual ftp directory,

ftp://ftp.iap.fr/pub/from_users/bertin/sextractror

?

there are several older version of sextractor in there, including

sextractor-2.3.2-1.i586.rpm

cheers
henry

[jaron_kurk]

No, I had not (as there is no link from the terapix webpage, maybe a good idea?), but there it is. Thanks a lot!

[Emmanuel Bertin]

Thanks for the suggestion. I have added a link to the SExtractor homepage.
- Emmanuel.

[npirzkal]

I am getting problems with segmentation files that Sextractor produced. The IDs are truncated at values of 2**16 again. This used to be the case in older versions of Sextractor (<2.4) and the problem seems to have re-appeared. This is a problem of course when dealing with large images containing more than 65536 objects

[Emmanuel Bertin]

Thanks for the bug report. This is weird. I will have a look at this when I am back (next week).
- Emmanuel.