code: public function populate($arrAll)
      {
          $this->arr = array_chunk($arrAll, $this->size->cols);
  
          return $this;
      }
docs: Puts all values into the matrix.
  
  Argument is a simple array of one dimension. If the matrix has 3 columns
  and 2 rows, the the argument must have 6 elements. Under the hood, the
  given array is split to fit the matrix.
  
  By the way, you can use rows and colunms in place of this method.
  
  @param  array  $arrAll
  @access public
  @return Matrix