[daip] Re: AIPS Fitting gaussians to slice

[Eric Greisen]

Vic Hughes writes:
 > Hi,
 > am having trouble with AIPS OCT99 version, installed on linux RED HAT,
 > version5.
 > Can obtain a SLICE and display on the tektronix monitor, and can use
 > SLFIT to fit one gaussian, but cannot fit more than one, it gives an
 > error and tells me that the second component has zero width. If I try to
 > fit three gaussians, it gives an error and tells me that it cannot fit
 > component three. Is there any way around this?
 > 
 > TKSET does not seem to work. It provides cross hairs, but will not accept
 > the pressing of any key.
 > 
 > I called you, but perhaps this is a better way of communicating.
 > 

     I am in Socorro for 7 months.  505-835-7236 at the office.  But
e-mail is usually better.

     We had trouble too with TKSET and so I wrote a set of TV verbs to
replace it - they are in 31DEC99 and described in the 1 April 2000
AIPSLetter.  The inputs to SLFIT are confusing:
   1. The units are those of the TKSLICE plot (Jy or mJy, or ??, vs
      arc sec or deg or pixel or ...)
   2. GPOS and GWIDTH are arrays and only the first subscript is
      used:  Thus GPOS(1,i) and GWIDTH(1,i) give the parameters for
      the i'th component.  Thus, an example:
           NGAUSS = 3
           GMAX   = 100, 300, 20
           GPOS   = -23, 0, 3, 0, 35
           GWIDTH = 3,0,0, 5,0,0, 7
      where I assume mJy, and arc sec for the units.

You might want to consider getting 31DEC99 sometime.

Hope this helps, Eric