PGPLOT Module: PGPT -- draw several graph markers


SUBROUTINE PGPT (N, XPTS, YPTS, SYMBOL)
INTEGER N
REAL XPTS(*), YPTS(*)
INTEGER SYMBOL

Primitive routine to draw Graph Markers (polymarker). The markers
are drawn using the current values of attributes color-index,
line-width, and character-height (character-font applies if the symbol
number is >31). If the point to be marked lies outside the window,
no marker is drawn. The "pen position" is changed to
(XPTS(N),YPTS(N)) in world coordinates (if N > 0).


Arguments
N (input) : number of points to mark.
XPTS (input) : world x-coordinates of the points.
YPTS (input) : world y-coordinates of the points.
SYMBOL (input) : code number of the symbol to be drawn at each
point:
-1, -2 : a single dot (diameter = current
line width).
-3..-31 : a regular polygon with ABS(SYMBOL)
edges (style set by current fill style).
0..31 : standard marker symbols.
32..127 : ASCII characters (in current font).
e.g. to use letter F as a marker, let
SYMBOL = ICHAR('F').
> 127 : a Hershey symbol number.

Note: the dimension of arrays X and Y must be greater than or equal
to N. If N is 1, X and Y may be scalars (constants or variables). If
N is less than 1, nothing is drawn.