code: public void set( int row , int col , double value ) {
          ops.set(mat, row, col, value);
      }
docs: Assigns the element in the Matrix to the specified value.  Performs a bounds check to make sure
  the requested element is part of the matrix.
  
  @param row The row of the element.
  @param col The column of the element.
  @param value The element's new value.