# dualCone -- computes the dual Cone

## Synopsis

• Usage:
Cv = dualCone C
• Inputs:
• Outputs:
• Cv,

## Description

The dual cone of C in QQ^n is the cone in the dual ambient space (QQ^n)^*, given by {p in (QQ^n)^* | p*c >= 0 for all c in C}.

 i1 : C = posHull matrix {{1,2},{2,1}} o1 = {ambient dimension => 2 } dimension of lineality space => 0 dimension of the cone => 2 number of facets => 2 number of rays => 2 o1 : Cone i2 : Cv = dualCone C o2 = {ambient dimension => 2 } dimension of lineality space => 0 dimension of the cone => 2 number of facets => 2 number of rays => 2 o2 : Cone i3 : rays Cv o3 = | 2 -1 | | -1 2 | 2 2 o3 : Matrix ZZ <--- ZZ

## Ways to use dualCone :

• "dualCone(Cone)"

## For the programmer

The object dualCone is .