code: public Matrix copy()
      {
          Matrix X = new Matrix(m, n);
          double[][] C = X.getArray();
          for (int i = 0; i < m; i++)
          {
              for (int j = 0; j < n; j++)
              {
                  C[i][j] = A[i][j];
              }
          }
          return X;
      }
docs: Make a deep copy of a matrix