code: function _getRows(matrix) {
    var rows = [];
    for (var i=0; i<matrix.size.rows; i++) {
      rows.push([]);
      for (var j=0; j<matrix.size.columns; j++)
        rows[i].push(matrix.values[matrix.size.columns * i + j]);
    }
    return rows;
  }
docs: Creates an array of the rows of a matrix
  
  @param {Matrix} matrix
  @returns {Array} rows array: two-dimensional