  plgxax(digmax, digits)
  **********************

  plgxax

  Returns current values of the digmax and digits flags for the x axis.
  digits is updated after the plot is drawn, so so this routine should only
  be called _a_f_t_e_r the call to plbox (or plbox3) is complete. Annotation for
  more information.

  digmax (PLINT *, output): Pointer to variable with the maximum number of
  digits. If nonzero, the printed label will be switched to a floating point
  representation when the number of digits exceeds digmax.

  digits (PLINT *, output): Pointer to variable with the actual number of
  digits for the numeric labels (x axis) from the last plot.

