Check if Points are within Polygon
Check the location of point(s) with respect to a polygon.
matrix containing the
x,y-coordinates of the vertices of the polygon boundary.
matrix of containing the
x,y-coordinates of the point locations.
An integer vector of indicators for each point in
error when number of polygon vertices exceeds 3000;
outside the polygon;
at the polygon boundary;
inside the polygon.
This function is provided here so that users do not need to load other packages, as it is not available in the base R packages. THE VERTICES MAY BE LISTED CLOCKWISE OR ANTICLOCKWISE
The return values have been changed from the original ones so that the point is inside (including at the boundary) if positive.
This Fortran code comes from Wm Randolph Franklin, Electrical, Computer, and Systems Engineering Department, Rensselaer Polytechnic Institute, Troy, New York, at website http://www.ecse.rpi.edu/Homepages/wrf.