# rays -- calculates the extreme rays of the cone; invokes "rays" from 4ti2

## Synopsis

• Usage:
rays(A)
• Inputs:
• A, , defining the cone $\{z : Az = 0, z \ge 0 \}$
• Outputs:
• B, , whose rows are the extreme rays of the cone $\{z : Az = 0, z \ge 0 \}$

## Description

 i1 : A = matrix "1,1,1,1; 1,2,3,4" o1 = | 1 1 1 1 | | 1 2 3 4 | 2 4 o1 : Matrix ZZ <--- ZZ i2 : B = syz A o2 = | 1 2 | | -2 -3 | | 1 0 | | 0 1 | 4 2 o2 : Matrix ZZ <--- ZZ i3 : rays(transpose B) o3 = | 0 1 2 3 | | 3 2 1 0 | 2 4 o3 : Matrix ZZ <--- ZZ

## Ways to use rays :

• "rays(Matrix)"

## For the programmer

The object rays is .