method

trace

v1_8_7_330 - Show latest stable - Class: Matrix

trace()

public

Returns the trace (sum of diagonal elements) of the matrix.

Matrix[[7,6], [3,9]].trace
  => 16

# File lib/matrix.rb, line 783
  def trace
    tr = 0
    0.upto(column_size - 1) do
      |i|
      tr += @rows[i][i]
    end
    tr
  end