[daip] IMAGR problem

[Cormac Reynolds]

hi,

I am using IMAGR to map a dataset, but am getting a very strange
result. I have run IMAGR on the same dataset several times, and
sometimes it crashes (I include the error message at the bottom of
this email). 

The crashing seems to be caused by choosing a particular value for the
image size and convolution type. If I default everything except
niter>0, cells=0.0027 and imsize=512 it fails with the mysterious
message below. It also fails if cells=0.0054 and imsize=256 or if
cells=0.00135 and imsize=1024. However, other combinations of cellsize
and imsize appear to run normally. I also notice that if I set
xtype=ytype=4 then it runs normally every time. No other inputs seem
to have any bearing on the result. 

I've tested this on two machines with different accounts and have been
able to reproduce the result every time. I've also been able to
reproduce it in 31DEC06, 31DEC05 and 31DEC04, but not in 31DEC02. We
don't have the 31DEC07 installed here yet. 

In case it is useful, I have put the (very small) dataset where I see the
problem on our ftp server: 
ftp://ftp.jive.nl/pub/reynolds/eb032a_0231+132.fits

Any idea what could be going on here? 

thanks,
Cormac.


Error message:

jop15 > IMAGR1: Beginning channel    1 through    1 with  8 IFs
jop15 > IMAGR1: IMACPY: Copied      771 visibilities to be imaged
jop15 > IMAGR1: UVWAIT: begin finding uniform weights
jop15 > IMAGR1: UVWAIT: Average grid weight  2.540E-01
jop15 > IMAGR1: UVWAIT: Adding temperance S  5.079E-02
jop15 > IMAGR1: UVWAIT: begin applying uniform or other weights
jop15 > IMAGR1: UVWAIT: Sum of weights in  7.317E+00 and out  4.118E+00
jop15 > IMAGR1: UVWAIT: Noise is increased by a factor 1.916 due to weighting
jop15 > IMAGR1: UVWAIT: Average summed weight  2.539E-01 over       4838 vis
jop15 > IMAGR1: Create 0231+132    .IBM001.  62 (MA)  on disk  1  cno  127
jop15 > IMAGR1: Create 0231+132    .ICL001.  61 (MA)  on disk  1  cno  128
jop15 > IMAGR1: GRDFLT: X and Y convolution type = SPHEROIDAL
jop15 > IMAGR1: GRDFLT: X and Y parms =  3.0000  1.0000
jop15 > IMAGR1: GRDFLT: convolution function sampled every 1/100 of a cell
jop15 > IMAGR1: GRDMEM: Ave    8 Channels; 6.613240E+09 to 6.694865E+09 Hz
jop15 > IMAGR1: Field   1 Sum of gridding weights =  4.37170E+01
jop15 > IMAGR1: Field   1 Beam min = -438.2 MilliJy, max =    1.8      Jy
jop15 > IMAGR1: Field   1 fit FWHM =    3.716 x    3.420 Milliarcsec, PA=   -1.2
jop15 > IMAGR1: CLBHIS: minimum component 0.500 of current peak
jop15 > IMAGR1: QCLEAN: Make copy of data for filtering
jop15 > IMAGR1: Field   1 min = -837.0 MilliJy,max =    1.7      Jy
jop15 > IMAGR1: BGC Clean: using 1019 cell beam + residuals >     1.75      Jy
jop15 > IMAGR1:        0 Residual map points loaded
jop15 > IMAGR1: CLMPAC: NO RESIDUAL POINTS LOADED INTO AP, I QUIT
jop15 > IMAGR1: CLMPAC: ERROR LOADING RESIDUALS FOR CLEAN field number 0001
jop15 > IMAGR1: CLNCYC: ERROR CLEANING CLEAN process object
jop15 > IMAGR1: CLNUV1 : ERROR CLEANING CLEAN process object
jop15 > IMAGR1: CLNUV : ERROR CLEANING CLEAN process object
jop15 > IMAGR1: Deleting UV work file:
jop15 > IMAGR1: Destroyed  1 extension files of type AN
jop15 > IMAGR1: Destroyed  1 extension files of type FQ
jop15 > IMAGR1: Destroyed UV image file: catno=      1 disk= 4