[daip] costar/stfactor

[Lorant Sjouwerman]

On Thu, 7 Jul 2005, Lorant Sjouwerman wrote:

#AIPS 1: COSTAR:  Verb to plot a symbol at a coordinate on the TV
#AIPS 1: Adverbs     Values                 Comments
#AIPS 1: ----------------------------------------------------------------
#AIPS 1: STFACTOR     70                    Scale radius = 2 pixels *
#AIPS 1:                                    STFACTOR
#
#gives about 20" with a pixel of 0.1" - but according to the formula
#above STFACTOR should be 100 to get 20" - I think STFACTOR is divided by 
#root(2) somewhere so either the help or code needs to be updated
#I can work around it by dividing by/multiplying with root(2).
#

Maybe I should also have said that I used a circle symbol

In AU5B.FOR, lines 445-452, one specifies a RECTANGULAR area around the
center position by expanding all corners by 2*STF - i.e, effectively the
corners lie at a radius root(2)*(2*STF) away from the center.

One uses these corner points in PLTPNT.FOR, lines 160-163 and 168-171, to
define the circle radius, for a circle through the corners - i.e., outside 
the rectangular area, then thus in my view root(2) too large

Anyway

Regards,

Loránt Sjouwerman - Scientific Services - lsjouwerman at nrao.edu
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