%N uvupdate %F $MIR/src/subs/uvio.c
%D Check whether any "important" variables have changed.
%P rjs
%: uv-i/o
%B
FORTRAN call sequence:
        logical function uvupdate(tno)
        integer tno

  This checks whether any ``important variables'' has been updated in the
  last call to uvread or uvscan. Important variables are those flagged
  with the 'u' flag in a call to uvtrack.

  Input:
    tno         File handle of the uv file to check.                    
