code: function findLargestInRow (M, i) {
    // get the row:
    const m = M.elements;
    const n = M.dimension;
    const offset = i;
  
    let j = 0;
    let lrgElem = _Math.abs(m[offset]);
    let lrgCol = j;
    for (j = 1; j < n; ++j) {
      const val = _Math.abs(m[offset + j * n]);
      if (val > lrgElem) {
        lrgCol = j;
        lrgElem = val;
      }
    }
    return lrgCol;
  }
docs: Finds the largest element in the matrix row.
  @memberof Helpers
  @param {Matrix2|Matrix3|Matrix4} M The matrix.
  @param {number} i The row index.
  @returns {number} The column index of the row's largest element.