%N uvinfo %F $MIR/src/subs/uvio.c
%D Get information about the last data read with uvread.
%P rjs
%: uv-i/o
%B
FORTRAN call sequence:
        subroutine uvinfo(tno,object,data)
        integer tno
        character object*(*)
        double precision data(*)

  This returns extra information about the data read in the last call
  to uvread.

  Input:
    tno         The handle of the uv file.
    object      Indicates what information is required. Currently
                this can be
                'velocity' returns "nread" numbers, giving the velocity
                           (km/s) of each channel.
                'restfreq' returns "nread" numbers, giving the rest
                           frequency (GHz) of each channel.
                'bandwidth' returns "nread" numbers, giving the bandwidth
                           (GHz) of each channel.
                'visno'    returns 1 number, which is the number of
                           visibilities read from this file.
                'frequency' returns "nread" numbers, giving the rest-frame
                           frequency (GHz) of each channel.
                'sfreq'    returns "nread" numbers, giving the sky frequency
                           (GHz) of each channel.
                'amprange' returns 3 numbers. The first gives the amplitude
                           selection for this record, the next two give
                           the selection range. Possible values of data(1) are
                           -1 : Data outside the range [data(2),data(3)]
                                was rejected.
                            0 : No amplitude selection.
                           +1 : Data inside the range [data(2),data(3)]
                                was rejected.
                'line'     returns 6 numbers, giving the linetype. Possible
                           values of data(1) are 1, 2 or 3, corresponding to
                           'channel', 'wide' and 'velocity'.
                           data(2) thru data(5) are n,start,width,step.
                           data(6) is the first window used.
                'variance' returns the variance (based on system temp)
                           of the first channel. If this cannot be determined
                           it returns 0.
  Output:
    data        The actual information returned.                        
