plotpolygon {zonohedra}

plot the generator polygon associated with a pointed zonohedron

Description

A zonohedron is pointed iff there is a vector n so the inner product of all the zonohedron generators with n is positive. In other terminology, it is pointed iff there is an open halfspace that contains all the generators.
When n exists, a neighborhood of 0 can be cut by a plane orthogonal to n and the intersection is a polygon. Since n is not unique, the polygon is only unique up to a 2D projective transformation.

Usage

plotpolygon( x, normal=NULL, points=TRUE, labels=TRUE )

Arguments

x

a zonohedron object as returned by the constructor zonohedron(). It must be pointed.

normal

the vector n to use - a non-zero numeric vector of length 3. If it is given, the validity is checked and if invalid it is an error.
If it is NULL, a few canonical normals are first tested for validity. If they are invalid, then a valid one is computed.

points

If TRUE then draw the vertices of the polygon

labels

If TRUE then draw labels, taken from the ground set of the simplified matroid, near the vertices

Details

The selected normal vector n is added to the title of the plot.

Value

The function returns TRUE; or FALSE in case of error.

See Also

zonohedron(), plot.zonohedron()