%N pgrnge %F $MIR/src/pgrnge.f
%D Choose axis limits
%B
      SUBROUTINE PGRNGE (X1, X2, XLO, XHI)
      REAL X1, X2, XLO, XHI

 Choose plotting limits XLO and XHI which encompass the data
 range X1 to X2.

 Arguments:
  X1, X2 (input)  : the data range (X1<X2), ie, the min and max values
                    to be plotted.
  XLO, XHI (output) : suitable values to use as the extremes of a graph
                    axis (XLO <= X1, XHI >= X2).
