reduceSum method

double reduceSum()

Return sum of all elements of this

Implementation

double reduceSum() {
  double sum = 0;
  for (int i = 0; i < n; i += 1) {
    for (int j = 0; j < m; j += 1) {
      sum += _base[i][j];
    }
  }
  return sum;
}