Matrix _ Sequence -- get entry of matrix

• Operator: _

• Usage:

  M_(i,j)

• Inputs:
  • M, a matrix, or a mutable matrix
  • i, a sequence, both integers
• Outputs:
  • the (i,j)-th entry of the matrix M, where M_(0,0) is the top left entry, a ring element

i1 : M = matrix{{1,2,3},{0,5,6}}

o1 = | 1 2 3 |
     | 0 5 6 |

              2       3
o1 : Matrix ZZ  <-- ZZ

i2 : M_(1,2)

o2 = 6

i3 : N = mutableMatrix M

o3 = | 1 2 3 |
     | 0 5 6 |

o3 : MutableMatrix

i4 : N_(1,0)

o4 = 0

i5 : N_(1,0) = 37

o5 = 37

i6 : N

o6 = | 1  2 3 |
     | 37 5 6 |

o6 : MutableMatrix