MATLAB Function Reference    

Detect points inside a polygonal region



IN = inpolygon(X,Y,xv,yv) returns a matrix IN the same size as X and Y. Each element of IN is assigned one of the values 1, 0.5 or 0, depending on whether the point (X(p,q),Y(p,q)) is inside the polygonal region whose vertices are specified by the vectors xv and yv. In particular:

IN(p,q) = 1
If (X(p,q),Y(p,q)) is inside the polygonal region
IN(p,q) = 0.5
If (X(p,q),Y(p,q)) is on the polygon boundary
IN(p,q) = 0
If (X(p,q),Y(p,q)) is outside the polygonal region


  inmem input