gstat (version 0.9-22)

point.in.polygon: do point(s) fall in a given polygon?

Description

verifies for one or more points whether they fall in a given polygon

Usage

point.in.polygon(point.x, point.y, pol.x, pol.y)

Arguments

point.x

numerical array of x-coordinates of points

point.y

numerical array of y-coordinates of points

pol.x

numerical array of x-coordinates of polygon

pol.y

numerical array of y-coordinates of polygon

Value

• logical array; FALSE if a point is strictly exterior to the polygon, TRUE if not (point is strictly interior to polygon, point is a vertex of polygon, or point lies on the relative interior of an edge of polygon)

References

Uses the C function InPoly(), in gstat file polygon.c; InPoly is Copyright 1998 by Joseph O'Rourke. It may be freely redistributed in its entirety provided that this copyright notice is not removed.

Examples

# open polygon:
point.in.polygon(1:10,1:10,c(3,4,4,3),c(3,3,4,4))
# closed polygon:
point.in.polygon(1:10,1:10,c(3,4,4,3,3),c(3,3,4,4,3))