sgeostat (version 1.0-27)

in.polygon: In-Polygon test

Description

Checks if points are in the interior of a polygon.

Usage

in.polygon(x0, y0, x, y)

Arguments

x0

coordinates of points to check

y0

see x0

x

coordinates defining the polygon

y

see x

Value

comp1

Description of `comp1'

comp2

Description of `comp2'

Details

Uses a simple points-in-polygon check combined with the polygon function.

Polygon is closed automatically.

References

Follows an idea from algorithm 112 from CACM (available at http://www.netlib.org/tomspdf/112.pdf)

See Also

in.convex.hull, polygon, in.chull

Examples

in.polygon(c(0,1),c(0,1),c(0,1,0,-1),c(-1,0,1,0))
# should give: TRUE FALSE