%N pgtick %F $MIR/src/pgtick.f
%D Draw a single tick mark on an axis
%B
      SUBROUTINE PGTICK (X1, Y1, X2, Y2, V, TIKL, TIKR, DISP, 
     :                   ORIENT, STR)
      REAL X1, Y1, X2, Y2, V, TIKL, TIKR, DISP, ORIENT
      CHARACTER*(*) STR

 Draw and label single tick mark on a graph axis. The tick mark is
 a short line perpendicular to the direction of the axis (which is not
 drawn by this routine). The optional text label is drawn with its
 baseline parallel to the axis and reading in the same direction as
 the axis (from point 1 to point 2). Current line and text attributes
 are used.

 Arguments:
  X1, Y1 (input)  : world coordinates of one endpoint of the axis.
  X2, Y2 (input)  : world coordinates of the other endpoint of the axis.
  V      (input)  : draw the tick mark at fraction V (0<=V<=1) along
                    the line from (X1,Y1) to (X2,Y2).
  TIKL   (input)  : length of tick mark drawn to left of axis
                    (as seen looking from first endpoint to second), in
                    units of the character height.
  TIKR   (input)  : length of major tick marks drawn to right of axis,
                    in units of the character height.
  DISP   (input)  : displacement of label text to
                    right of axis, in units of the character height.
  ORIENT (input)  : orientation of label text, in degrees; angle between
                    baseline of text and direction of axis (0-360°).
  STR    (input)  : text of label (may be blank).
