[daip] subtracting 'calibrated' source models from UV data

[Eric Greisen]

Huib Intema writes:
 > Dear Eric,
 > 
 > Eric Greisen wrote:
 > > Would the task DIFUV suffice?
 > >   
 > Thanks, I missed that one. Can you tell me what happens to a DIFUV 
 > output visibility when one of the two input visibilities is flagged, 
 > e.g. has zero weight? Will it also be flagged?
 > 

I had fogotten it too - yes it flags the sample if either one is
flagged.

Eric Greisen