`holes`

Returns the holes of a polyshape as an array of polyshape objects.

Category: Mathematics > Computational Geometry

Syntax

H = holes(pshape)

One polyshape per hole boundary.

H = holes(pshape, I)

Only the holes selected by the index I.

Description

The holes are returned as ordinary filled shapes, so you can ask for their area or centroid, or fill them. This is the inverse of making holes with subtract. To drop the holes from the shape, use rmholes.

Input arguments

pshape: A polyshape object.

Output arguments

H: Array of polyshape objects, each describing a hole as a solid polygon. If there are no holes it is an empty polyshape.

Example

Extract a hole

P = polyshape([0 4 4 0], [0 0 3 3]);
H = polyshape([1 2 2 1], [1 1 2 2]);
D = subtract(P, H);
h = holes(D);
disp(area(h))
disp(h.Vertices)

Output

holes