[daip] New Ticket - [!KQH-524344]: IMAGR bug

[Stephen Bourke]

New Ticket: IMAGR bug

Hi,
I think I've found a bug in IMAGR. It happens on some but not all datasets, when using primary beam correction, multi-resolution clean, and frequency tolerance. IMAGR proceeds normally for a few iterations of clean and then reports NaN values for min/max (see below). The task finishes normally, but the resulting maps are blank. I'm using the 31DEC12 update with the MNJ, although it seems present in 31DEC11 too. The problem can be seen in the following dataset:
http://www.aoc.nrao.edu/~sbourke/imagr_test.fits
with the following parameters triggering the behaviour:
NCHAV      64
CELLSIZE   0.2 0.2
IMSIZE     2048 2048
NITER      500
OVERLAP    2
IMAGRPRM   25, 0
NGAUSS     3
WGAUSS     0, 0.6325, 2, 0
FQTOL      100000

If FQTOL is lowered to 50000, (or multi-res clean, or primary beam correction turned off) it works fine.

Regards,
Stephen.


TEST-P> IMAGR1: SETDO3: imaging done with one tangent plane
TEST-P> IMAGR1: VISDFT: Begin DFT component subtraction
TEST-P> IMAGR1: VISDFT: fields 2 - 2 chns 1 - 1073 in 22 CC models
TEST-P> IMAGR1: VISDFT: Model components of type Gaussian
TEST-P> IMAGR1: I Polarization model processed
TEST-P> IMAGR1: VISDFT at visibility number           1
TEST-P> IMAGR1: Field    1 min =    NaN      Jy,max =    NaN      Jy
TEST-P> IMAGR1: Field    3 min =    NaN      Jy,max =    NaN      Jy
TEST-P> IMAGR1: Field    2 min =    NaN      Jy,max =    NaN      Jy
TEST-P> IMAGR1: No fields left to Clean
TEST-P> IMAGR1: Merging the Clean components files
TEST-P> IMAGR1: Field    1 compressed from         0 to         0 components
TEST-P> IMAGR1: Field    2 compressed from        19 to         5 components
TEST-P> IMAGR1: Field    3 compressed from         0 to         0 components
TEST-P> IMAGR1: Making images for fields    1 through    3
TEST-P> IMAGR1: Field    1 min =    NaN      Jy,max =    NaN      Jy
TEST-P> IMAGR1: Field    2 min =    NaN      Jy,max =    NaN      Jy
TEST-P> IMAGR1: Field    3 min =    NaN      Jy,max =    NaN      Jy

Ticket Details
===================
Ticket ID: KQH-524344
Department: AIPS Data Processing
Priority: Default
Status: Open
Link:  https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=2181