getDiagonal -- Extract the diagonal of a matrix

• Usage:

  v = getDiagonal(A)

• Inputs:
  • A, a matrix,
• Outputs:
  • v, a list,

i1 : A = random(QQ^4, QQ^4)

o1 = | 9/2 7/9  7   5/4  |
     | 9/4 7/10 3/7 2/9  |
     | 3/4 7/10 6/7 3/10 |
     | 7/4 7/3  6   3/7  |

              4       4
o1 : Matrix QQ  <-- QQ

i2 : v = getDiagonal A

      9   7  6  3
o2 = {-, --, -, -}
      2  10  7  7

o2 : List