METHOD

 

        ANALYSE\METHOD Arg [Parameters ...]

    Select the line profile for fits. Five type of profiles are available.
      - GAUSS     Select gaussian profiles.
        Up to 5 Gaussian, dependent  or  independent  can  be  fitted  in  a
        spectrum,  according  to  command lines. Variables are Area Velocity
        and Width (FWHM).
      - SHELL     Horn-type profiles for Circumstellar Shells.
        Variables are 1) Area, 2) Position, 3) Full Width at zero level, and
        4)  Horn-to-center  ratio (-1 for parabolic optically thick lines, 0
        for flat-topped lines, Infinity for perfectly double peaked  lines).
        Profiles  are  symmetric. Up to 5 dependent or independent lines may
        be fitted. Area units are K.MHz.
      - NH3(1,1) or NH3(2,2) or NH3(3,3)
        Compute ammonia line profiles,  with  the  assumptions  of  gaussian
        velocity  distribution  and equal excitation temperatures. Variables
        are 1) Main group  opacity  times  (  Excitation  temperature  minus
        Background  temperature),  2)  Velocity, 3) Width, and 4) Main group
        opacity.  Up to 3 independent lines may be fitted,  but  it  may  be
        slow...
      - HFS FileName    for HyperFine Structure
        This is very similar to the  NH3  method,  but  the  coefficient  to
        describe the hyperfine structure are read in the file FileName.  The
        first line of  this  file  must  contain  the  number  of  hyperfine
        components   (<  40).   The  other  lines  must  contain,  for  each
        component, the velocity  offset  and  the  relative  intensity.  The
        parameters are the same as for NH3 method.
      - CONTINUUM       for Continuum drifts.
        Fit a single gaussian and a linear baseline at the same  time,  with
        automatic   determination  of  the  parameters.  Uses  beam-switched
        information for  two-component  fitting  if  required.  The  command
        METHOD  CONTINUUM  accept additional arguments, which can be used to
        customize the fit.

    METHOD CONTINUUM [Width [Area_Ratio [Width_Ratio]]]
    where
      - Width is the width of the beam in arc seconds. By default, Width  is
        a free parameter.
      - Area_Ratio is the reference to main beam area ratio, used for  beam-
        switch observing. By default, Area_Ratio is 1.
      - Width_Ratio is the reference to main  beam  width  ratio,  used  for
        beam-switch observing. By default, Width_Ratio is 1.
    A * can be used instead of a numerical value  for  each  parameter,  and
    indicates that the parameter is free.

    Note that in command LINES, one enters the peak line antenna temperature
    instead  of  the first variable in the guesses, except for SHELL method.
    Command LINES has no effect for CONTINUUM.

    CONTINUUM and GAUSS methods only are relevant for continuum data,  while
    GAUSS, SHELL, NH3 and HFS methods can be used for spectroscopic data.