ccw {GEOmap}

Counter Clockwise Whorl

Description

Used for determining if points are in polygons.

Usage

ccw(p0, p1, p2)

Arguments

p0

point 0

p1

point 1

p2

point 2

Value

returns 1 or 0 depending on position of points

Author(s)

Jonathan M. Lees <[e-mail]>

See Also

Lintersect

Examples

l1 = list(p1=list(x=0, y=0), p2=list(x=1,y=1))
l2 = list(p1=list(x=6, y=4), p2=list(x=-1,y=-12))

ccw(l1$p1, l1$p2, l2$p1)