`nsidedpoly`

Creates a regular polygon with a given number of sides, as a polyshape.

Category: Mathematics > Computational Geometry

Syntax

pshape = nsidedpoly(n)

Regular n-gon centered at the origin with unit circumradius.

pshape = nsidedpoly(n, 'Center', c, 'Radius', r)

Sets the center c = [x y] and the circumradius r.

pshape = nsidedpoly(n, 'Center', c, 'SideLength', s)

Sets the side length instead of the radius.

Description

The vertices lie on a circle and are equally spaced. The area is n/2 * r^2 * sin(2*pi/n), so a hexagon with unit radius has area about 2.598. With a large n the polygon approaches a disc, which is a simple way to build a circular region as a polyshape.

Input arguments

n: Number of sides, an integer of at least 3.
'Center': Two-element vector with the center. Default [0 0].
'Radius': Distance from the center to each vertex. Default 1.
'SideLength': Length of each side; cannot be combined with 'Radius'.

Output arguments

pshape: A polyshape with n vertices.

Example

Hexagon area and perimeter

H = nsidedpoly(6);
disp(numsides(H))
disp(area(H))
disp(perimeter(H))

Output

     6
    2.5981
     6

nsidedpoly