[argyllcms] dispcal and "conjgrad failed" error

  • From: Pablo d'Angelo <pablo.dangelo@xxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Thu, 31 Aug 2006 22:26:08 +0200

Hi all,

I have just received my new DTP-94, and started playing around with it.
I'm using ubuntu dapper on AMD64. I also managed to compile the source after
tweaking the Jamfiles, but the resulting dispcal always failed:

pablo@svalbart:~/src/argyll-0.60-jam/spectro$ ./dispcal -r
dispcal: Error - Unable to open the display

After that, I have downloaded the linux binaries from the argyllcms website.
(including patch2 update). They seem to work fine, until I get a "dispcal:
Error - Conjgrad failed" error while running:

pablo@svalbart:~/tmp/argyll-bin/bin$ sudo ./dispcal -t 6500 -e -y l -v  -c 1

I tried twice and it always got the error after a short computation. The
stdout logfile is attached (failed_stdout.txt)

Then I looked at this list and saw that this error has been seen before, and
decided to create a log file using the -D option as well. Now the
interesting thing is: This time it didn't crash!

pablo@svalbart:~/tmp/argyll-bin/bin$ sudo ./dispcal -D -t 6500 -e -y l -v
-c 1  FSC-S19_argyll.cal 2>stderr.log

The respective logs (successful_run_stdout.txt and
successful_run_stderr.txt) are also attached.

During the successful run, I just started dispcal and jumped straigt to the
calibration, 6). In the previous runs I had adjusted the display using
options 1 to 5 (sequentially).

So dispcal seems to break somehow if the options 1-5 are used before option
6, the final calibration.

The workaround is to quit dispcal after adjusting the monitor, restart
dispcal and then just do the calibration.


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