[daip] True Stokes

[Eric Greisen]

Mark Reid wrote:
> 
> Eric,
> 
>    There is somethings that I don't understand about the "true Stokes" 
> conversion when writing a FITS tape.
> 
> 1) FITTP has "DOSTOKES", but FITAB doesn't.  Does FITAB also convert to 
> true Stokes?
> 
> 2) I don't think I have ever set DOSTOKES>0 (it defaults to -1), and yet 
> I seem to have tapes with Stokes I,Q for data that started RR,LL.
> 
> 3) If one converts RR,LL to I, one must apply calibration tables before 
> converting.   Has that been done?   Assuming it has, I don't see how the 
> CL tables that are on the tape of any value (and actually could cause 
> trouble)?

FITTP is the only task that uses this adverb this way.  DEFLG, FLAGR, 
and SNFLG do use it in another meaning and you may have changed its 
value for SNFLG and then not noticed for FITTP.  And, NO, FOTTP does not 
apply calibration so the conversion is bogus.  I have to remove that option!

Eric Greisen