Macaulay2 » Documentation
Packages » Polyhedra :: isPointed
next | previous | forward | backward | up | index | toc

isPointed -- checks if a Cone or Fan is pointed

Synopsis

Description

Tests if a Cone is pointed, i.e. the lineality space is 0. A Fan is pointed if one of its Cones is pointed. This is equivalent to all Cones being pointed.
i1 : C = coneFromHData(matrix{{1,1,-1},{-1,-1,-1}})

o1 = C

o1 : Cone
i2 : isPointed C

o2 = false
i3 : C = intersection{C, coneFromHData(matrix{{1,-1,-1}})}

o3 = C

o3 : Cone
i4 : isPointed C

o4 = true

Ways to use isPointed :

For the programmer

The object isPointed is a method function.