  plerry(n, x, ymin, ymax)
  ************************

  plerry

  Draws a set of n vertical error bars, the i'th error bar extending from
  ymin[i] to ymax[i] at x coordinate x[i]. The terminals of the error bar are
  of length equal to the minor tick length (settable using plsmin).

  n (PLINT, input): Number of error bars to draw.

  x (PLFLT *, input): Pointer to array with x coordinates of error bars.

  ymin (PLFLT *, input): Pointer to array with y coordinates of lower
  endpoint of error bars.

  ymax (PLFLT *, input): Pointer to array with y coordinate of upper
  endpoint of error bar.

