Documentation on uvputhd

Task: uvputhd
Purpose: Allows user to alter values of header variables in uv dataset
Categories: vis, uv, header

    UVPUTHD allows the user to change the values of uv variables in a
    uv dataset. All occurances of the variable are changed to the
    new value. If the variable is an array, all new values must be
    entered in sequential order. If the user desires to set all members 
    of an array to a single value, only one value need be entered.
    Note: PUTHD must be used to use the uv override principle, but
    can only be used for single items, i.e. uv variables which are
    not an array.

Key: vis
    Name of the input MIRIAD dataset. Only one dataset is allowed.
    No default.

Key: hdvar
    Name of header variable to be changed. Refer to user manual or
    run VARLIST to see the selection of allowed variable names.

Key: type
    Type of variable, either integer (i),real (r), double precision (d), 
    or ascii (a). Unused if variable already exists in the data file.

Key: length
    Length of array of variable values. Unused if variable already 
    exists in data file.

Key: nvals
    Number of new values for varibles that are being entered in varval.

Key: varval
    New values of header variable - if the variable is an array
    all values must be specified or will assume one value for all.

Key: out
    Name of the output dataset. No default.