LINMOS problems

[and460]

Hi Guys,

Craig Anderson here from Sydney Uni. I've been trying to stitch together some CABB spectral cubes with linmos, and it's falling over for reasons I don't understand. The files I want to mosaic are four stokes Q cubes (one for each pointing in a sub-mosaic I'm working on), spanning a 256MHz frequency range. It seems to work sometimes if I only feed it only a couple of the pointings, but not always.

Any ideas? Perhaps the files are too big/much for linmos to handle? Any help much appreciated. The terminal inputs and output is reproduced below:


linmos% inp
Task: linmos
in = ./forn_170.1972.clmapqc/,./forn_171.1972.clmapqc/,./forn_134.1972.clmapqc/,./forn_135.1972.clmapqc/
out = ./cubemos.mos
rms =
options =
linmos% go

linmos: Revision 1.14, 2011/05/09 22:46:54 UTC

Processing image ./forn_170.1972.clmapqc/
Processing image ./forn_171.1972.clmapqc/
### Warning: Error writing to scratch file; check your $TMPDIR
### Fatal Error: Invalid argument
linmos%

[Mark.Wieringa]

Hi Craig,

it looks like you are running out of disk space during the linmos operation. As the message implies, you could check what the TMPDIR environment variable is set to. If it is not set to an area with lots of free space, you should change it in the terminal where you are starting miriad from, then start miriad and try linmos again.

Cheers,

Mark

[Mark.Wieringa]

Hi again,

after looking at the code, it appears this error message could also be triggered if the output file would be larger than 8GB (more than 2 billion pixels). For a cube with 256 channels that would limit you to image sizes of about 2800 pixels squared.
If that is indeed the case, try breaking up the cube in a few channel ranges, or a few sky areas to stay below this limit.

We're looking at how we can remove limits like this from miriad.

Cheers,

Mark

[and460]

OK - thanks Mark. I'll take a look at it.

Cheers,

Craig.