[daip] Re: beam patch

[Eric Greisen]

Crystal Brogan writes:
 > 
 > Hi Eric,
 > 
 > I hope all is well with you? I wondered if you could explain
 > a warning message that I see frequently in IMAGR when I'm
 > doing 3-D cleaning of complex Galactic plane fields.
 > 
 > IMAGR1: CDECID: CANNOT OBTAIN BEAM PATCH - MAP LIMIT PROPERLY
 > 
 > After stating this, it seems to go on cleaning more or less normally. It
 > seems to happen when a "remake images"  command is needed but has not yet
 > been triggered internally.  i.e. if I give an explicit remake images
 > command through the TV this warning goes away (for awhile).
 > 
 > What does it mean? Is it detrimental?

Yes - I am suprised that there are not then messages like loaded too
many points to the AP memory.  The comment in the code says

C                                       If program gets here there is a
C                                       serious problem. e.g. residual
C                                       map has a constant (or nearly)
C                                       value, set NRESKP.
      KPAT = MINPCH - 1
C                                       Use next to highest bin
      JLEV = NBMHIS - 1
C                                       Let user know
      MSGTXT = 'CDECID: CANNOT OBTAIN BEAM PATCH - MAP LIMIT PROPERLY'
      CALL MSGWRT (8)

It occurs to me that you are perhaps Cleaning large numbers of facets
over big areas - to what have you set MAXPIXEL?  I suspect that
something substantially bigger than the default may be appropriate for
what you are doing - how many pixels are in the Clean boxes?

Cheers, 

Eric

PS This was my first day back after a week's trip to ADASS and some
birding.