public int getVertical(int i, int j, int r) {

		int sum = 0;
		int imax = this.length;
		int jmax = this.width;
		for (int n = 0; n <= 2 * r; n++) {
			int ii = topo.idI(i - r + n, j, imax, jmax);
			int jj = topo.idJ(i, j, imax, jmax);
			
			if ( 
				(!(ii < 0) && !(ii >= imax)) &&
				(!(jj < 0) && !(jj >= jmax)) && 
				(ii != i || jj != j )
			   )
			{
				sum += this.getCell(ii, jj).toBit();
			}
		}
		
		return sum;
	}