code: public void initializeGrid(double value) {
          for (int i = 0; i < grid.length; i++) {
              for (int j = 0; j < grid[0].length; j++) {
                  for (int k = 0; k < grid[0][0].length; k++) {
                      grid[k][j][i] = value;
                  }
              }
          }
      }
docs: Method initialise the given grid points with a value.