[daip] VPLOT

[Eric Greisen]

Rick Perley writes:
 >     Eric:
 > 
 >     I'm now getting into polarization issues, and need some more 
 > sophisticated plotting tools.  VPLOT is a nice program, but it's missing 
 > a few capabilities that would be useful for polarization.    Perhaps 
 > there's a better way to do these, but if not, it would be useful to have:
 > 
 >     1) Ability to plot visibilities against parallactic angle.  (Also, 
 > against elevation, and even azimuth). 

       done
 > 
 >     2) The 'POLPLOT' adverb should allow ratios of Stokes:  Q/I, V/I, 
 > etc.  (In these cases, 'true' I should be required, not the 'RR' and 
 > 'LL' surrogates). 

       done for q/i, u/i, v/i - did you require more?
 > 
 >     3) We'll need to be able to plot the polarization model, including 
 > both the source polarization, and the 'D' term contamination, along with 
 > the data.  This is needed to see how well the D-terms are matching the 
 > the data. 

       not easy - may not even fit in task

 > 
 >     4) It would be nice to have the plotted points connected by lines, 
 > as you have done for other plotting programs. 

        done

Eric