rays(Matrix) -- calculates the extreme rays of the cone; invokes "rays" from 4ti2

• Function: rays

• Usage:

  rays(A)

• Inputs:
  • A, a matrix, defining the cone $\{z : Az = 0, z \ge 0 \}$
• Optional inputs:
  • Precision (missing documentation) => an integer or a string, default value 64, 32, 64, or "arbitrary", the precision of the integers used during the computation
• Outputs:
  • B, a matrix, whose rows are the extreme rays of the cone $\{z : Az = 0, z \ge 0 \}$

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