marchine learning 之 ManhattanDistance

/**曼哈頓街區距離
 */
public class ManhattanDistance {

    public double manhattanDistance(Instance a,Instance b){
        if (a.noAttributes() != b.noAttributes())
            throw new RuntimeException("兩個數據實例的屬性數目不一致");
        double sum =0.0;
        for (int i = 0;i<a.noAttributes();i++){
            sum += Math.abs(a.value(i) - b.value(i));
        }
        return sum;
    }
}