package com.objecteye.utils;

import org.springframework.stereotype.Component;

@Component
public class CompareDistance {
    /**
     * 求两个double[]数组的欧式距离
     *
     * @param vector1   数组1
     * @param distance  归一化之后的距离
     * @param vector2   数组2
     * @param distance1 归一化之后的距离
     * @return 距离
     */
    public double simDistance(double[] vector1, double distance, double[] vector2, double distance1) {
        double score = 0;
        for (int i = 0; i < vector1.length; i++) {
            score += vector1[i] * vector2[i];
        }
        score = score / (distance * distance1);
        return score < 0 ? 0 : score;
    }

    /**
     * 数组归一化之后的距离
     *
     * @param vector1 数组
     * @return 归一化之后的距离
     */
    public double getDistance(double[] vector1) {
        double distance = 0;
        double maxa = 0;
        for (int j = 0; j < vector1.length; j++) {
            if (vector1[j] > maxa) {
                maxa = vector1[j];
            }
        }
        for (int j = 0; j < vector1.length; j++) {
            vector1[j] = (vector1[j] / maxa);
            distance += vector1[j] * vector1[j];
//            distance += (vector1[j] / maxa) * (vector1[j] / maxa);
        }
        return Math.sqrt(distance);
    }

}