--- a/scripts/geometry/inpolygon.m	Tue Mar 07 01:01:42 2023 -0500
+++ b/scripts/geometry/inpolygon.m	Tue Mar 07 16:02:10 2023 -0500
@@ -39,9 +39,9 @@
 ## @end deftypefn
 
 ## Algorithm: The method for determining if a point is in a polygon is based on
-## the algorithm shown on
-## http://local.wasp.uwa.edu.au/~pbourke/geometry/insidepoly/
-## and is credited to Randolph Franklin.
+## the PnPoly algorithm from Prof W. Randolph Franklin,
+## (Rensselaer Polytechnic Institute, Troy NY), originally written in 1970.
+## URL: http://wrfranklin.org/pnpoly
 
 function [in, on] = inpolygon (x, y, xv, yv)
 
@@ -104,12 +104,12 @@
 %! clf;
 %! plot (xv, yv);
 %! hold on;
-%! plot (x(inside), y(inside), "@g");
-%! plot (x(! in), y(! in), "@m");
-%! plot (x(on), y(on), "@b");
+%! plot (x(inside), y(inside), "og");
+%! plot (x(! in), y(! in), "sm");
+%! plot (x(on), y(on), "^b");
 %! hold off;
-%! disp ("Green points are inside polygon, magenta are outside,");
-%! disp ("and blue are on boundary.");
+%! disp ("Green circles are inside polygon, magenta squares are outside,");
+%! disp ("and blue triangles are on the boundary.");
 
 %!demo
 %!  xv = [ 0.05840, 0.48375, 0.69356, 1.47478, 1.32158, ...
@@ -129,12 +129,12 @@
 %! clf;
 %! plot (xv, yv);
 %! hold on;
-%! plot (x(inside), y(inside), "@g");
-%! plot (x(! in), y(! in), "@m");
-%! plot (x(on), y(on), "@b");
+%! plot (x(inside), y(inside), "og");
+%! plot (x(! in), y(! in), "sm");
+%! plot (x(on), y(on), "^b");
 %! hold off;
-%! disp ("Green points are inside polygon, magenta are outside,");
-%! disp ("and blue are on boundary.");
+%! disp ("Green circles are inside polygon, magenta squares are outside,");
+%! disp ("and blue triangles are on the boundary.");
 
 %!test
 %! [in, on] = inpolygon ([1, 0, 2], [1, 0, 0], [-1, -1, 1, 1], [-1, 1, 1, -1]);