code: public double[][] copyValues2D()
      {
          double v[][] = new double[nRows][nCols];
  
          for (int r = 0; r < nRows; ++r) {
              for (int c = 0; c < nCols; ++c) {
                  v[r][c] = values[r][c];
              }
          }
  
          return v;
      }
docs: Copy the values of this matrix.
  @return the copied values