[daip] JMFIT question

[Eric Greisen]

Michael Bietenholz writes:
 > Minor technicality:
 > 
 > It seems to me that AIPS task CONVL, when invoked with OPCODE=Gaus on
 > a clean image used to give you a warning message when it couldn't
 > achieve the desired resolution set by BMAJ,BMIN,BPA.  The DEC02
 > version (haven't checked 03) yet, does not seem to do this anymore.
 > 
 > In the case when the desired beam is not achievable (smaller than the
 > existing one), the 31DEC02 version happily returns an image that
 > claims has the new, smaller clean beam.
 > 
 > I suggest that:
 >  1) the explicit warning be put back in.
 >  2) it return the correct header and flux scaling, so that the output
 >     image clean beam should be whatever it really was.  Ie. if the
 >     input clean beam is 1 x 1 and CONVL is asked to convolve with
 >     a clean beam of 2 x 0.5, the output image would in fact be convolved
 >     in one direction, and have a final clean beam of 2 x 1.  (The DEC02
 >     version's output would claim to have a clean beam of 2 x 0.5; and I
 >     believe flux density scaling appropriate for such a beam)
 > 

The DECONV subroutine was changed to help SAD, IMFIT, and JMFIT and in
the process (in 2001) the error code was set always 0.  I just changed
this to count the failed axes and changed CONVL to quit if the
deconvolution is required and it fails.  I think this is a better
response than trying to do something with the ill-defined values.

Eric Greisen