[daip] SMODEL bug

[Eric Greisen]

Bill Cotton writes:
 > Eric,
 > 
 >    I've discovered a conceptual error I copied from AIPS involving the
 > SMODEL parameter in UVSUB, CALIB, etc.  Essentially the phase shift
 > applied ignores the w term.  The error is zero for 0 shift (the usual
 > case) but increases quadratically with shift.  We've encountered the
 > problem in using point models with shifts of degrees in low frequency
 > data and this is a show stopper.

Thanks for the info - VSCDFT allowed the Z term on SMODEL while VISDFT
and VSFDFT set Z=0.  The Q routines below of course handled W*Z in
order to handle the 3D imaging.  I have corrected AIPS since I think
with a single SMODEL comp the user want the phase correction to be
complete, while in 2D imaging the CCs really should not have a Z*W
term.

Hope things are okay with you

Eric