[daip] Re: IMFIT

[Eric Greisen]

l.rodriguez at astrosmo.unam.mx writes:
 > Dear Eric:

   Please use daip at nrao.edu for mailing queries - I am sometimes on
vacation/travel and others can perhaps assist you.

 > 
 > There is something strange with the position angle that comes with the
 > deconvolution of IMFIT in the 31DEC03 VERSION of AIPS.
 > 
 > For example, in fitting a source I get:
 > 
 >              Deconvolution of component in asec
 >                 Nominal     Minimum     Maximum
 > Pos ang         142.899094  139.682343  174.929916 

The maximum was not properly initialized and so gave odd results.
This has been corrected in 31DEC04.  Note that SAD had a real error in
the position angle of deconvolution.  IMFIT and JMFIT just gave odd
Maximum P.A.'s.

 > 
 > Note the strange, large value for the "Maximum"
 > 
 > For the same data set, and using the same image in
 > an older version of AIPS (15OCT98 ) I get a
 > much more reasonable:
 > 
 > Pos ang         142.93159   139.72449   146.24817
 > 
 > In here, the "Minimum" and "Maximum" values are more or
 > less symmetric with respect to the "Nominal" value, as expected.


Eric Greisen