1 UV_FITC
        UV_FITC :  Fit spherically symmetric models to a UV data set

    This  task  allows  fitting  of  simple   models   directly   from   the
    visibilities.   The   models   are   linear  combinations  of  2  radial
    distributions, assumed to be centered  on  the  current  phase  tracking
    center. Use tasks UV_CENTER and UV_SHIFT if necessary before fitting.


    OLD VERSION: there is a sign error....


    The type of the first radial distribution. Available types are
        NONE      No function to fit (for 2nd function usually)
        POINT     Point source
        GAUSS     Gaussian sources
        DISK      Disk
        RING      Annulus
        EXPONENT  Exponential brightness
        POWER-1   B = 1/r
        POWER-2   B = 1/r^2
        POWER-3   B = 1/r^3
        PARABOLA  Parabolic brightness distribution

2 UVTABLE$
        TASK\CHARACTER "Input UV table"  UVTABLE$

    The UV table name.
2 CHANNEL$
        TASK\INTEGER "First and Last Channel to fit" CHANNEL$[2]

First and last channel to consider in the fitting process
2 FUNCTION_1$
        TASK\CHARACTER "First function"  FUNCTION_1$

    The type of the first radial distribution. Available  types  are  POINT,
    GAUSS,  DISK,  EXPONENT,  RING,  POWER-1, POWER-2, POWER-3, PARABOLA and
    NONE
2 PARA1$
        TASK\REAL "Guessed parameters"   PARA_1$[3]

    The 1st function initial parameters: Total flux,  angular  diameter  (in
    radians), and inner diameter (for the RING function).
2 FUNCTION_2$
        TASK\CHARACTER "Second function" FUNCTION_2$

    The type of the second radial distribution. Available types  are  POINT,
    GAUSS,  DISK,  EXPONENT,  RING,  POWER-1, POWER-2, POWER-3, PARABOLA and
    NONE
2 PARA_2$ TASK\REAL "Guessed parameters"   PARA_2$[3]

    The 2nd function initial parameters: Total flux,  angular  diameter  (in
    radians), and inner diameter (for the RING function).
2 RESULT$
        TASK\CHARACTER "Output file"     RESULT$

    The name of the output file  summarising  the  fit  results.  This  file
    contains for each channel:
       channel number, velocity, flux, size, size2, flux, size, size2
    and can be read by  a  GREG\COLUMN  command.  A  procedure  (pr:uvt)  is
    available to obtain plots from this file.

    In additions files named RESULTiii, where RESULT  is  the  name  of  the
    previous file, and iii the channel number, are created for each channel.
    This files contain the (optionally) binned data and the  fitted  values.
    A  procedure  (PR:UV_FITC)  is  available  to  obtain  plots from it. In
    addition GO UVALL uses these files for multi-channel plots.
2 QRANGE$
        TASK\REAL "Range (meters) and number of UV points" QRANGE$[3]

    The UV range in meter and the number of points used for binning
2 LAMBDA$
        TASK\REAL "Starting Lambda"      LAMBDA$ 0.01

    The minimization control parameter. Use the default of 0.01  unless  the
    program does not want to converge.
2 AMPLITUDE$
        TASK\LOGICAL "Fit Amplitude or Real values" AMPLITUDE$  NO

    Fit data from real part or amplitude of the visibilities.  Best  results
    are normally obtained from the real part.
2 BINDATA$
        TASK\LOGICAL "Bin data before Fit ?" BINDATA$ YES

    Radially average data into bins specified by QRANGE$ before starting the
    fit. This improves considerably the speed of convergence.
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