C++实现kmeans聚类算法

以下是一个简单的C++实现K-means聚类算法的示例：

#include <iostream>
#include <vector>
#include <cmath>

// 计算两个点之间的欧氏距离
double distance(std::vector<double>& point1, std::vector<double>& point2) {
    double sum = 0.0;
    for (int i = 0; i < point1.size(); i++) {
        sum += pow(point1[i] - point2[i], 2);
    }
    return sqrt(sum);
}

// 执行K-means聚类算法
void kmeans(std::vector<std::vector<double>>& data, int k) {
    int n = data.size();
    int dim = data[0].size();

    // 初始化聚类中心
    std::vector<std::vector<double>> centroids(k, std::vector<double>(dim));
    for (int i = 0; i < k; i++) {
        centroids[i] = data[i];
    }

    // 迭代更新聚类中心
    bool converged = false;
    while (!converged) {
        std::vector<int> clusterCounts(k, 0);
        std::vector<std::vector<double>> newCentroids(k, std::vector<double>(dim));

        // 分配数据点到最近的聚类中心
        for (int i = 0; i < n; i++) {
            double minDist = std::numeric_limits<double>::max();
            int closestCentroid = 0;
            for (int j = 0; j < k; j++) {
                double dist = distance(data[i], centroids[j]);
                if (dist < minDist) {
                    minDist = dist;
                    closestCentroid = j;                }
            }
            clusterCounts[closestCentroid]++;
            for (int d = 0; d < dim; d++) {
                newCentroids[closestCentroid][d] += data[i][d];
            }
        }

        // 更新聚类中心
        converged = true;
        for (int i = 0; i < k; i++) {
            for (int d = 0; d < dim; d++) {
                if (clusterCounts[i] > 0) {
                    newCentroids[i][d] /= clusterCounts[i];
                }
                if (newCentroids[i][d] != centroids[i][d]) {
                    converged = false;
                }
                centroids[i][d] = newCentroids[i][d];
            }
        }
    }

    // 输出聚类结果
    for (int i = 0; i < k; i++) {
        std::cout << "Cluster " << i << ": ";
        for (int d = 0; d < dim; d++) {
            std::cout << centroids[i][d] << " ";
        }
        std::cout << std::endl;
    }
}

int main() {
    // 示例数据
    std::vector<std::vector<double>> data = {{1.0, 2.0}, {2.0, 1.0}, {10.0, 12.0}, {12.0, 10.0}, {20.0, 22.0}, {22.0, 20.0}};
    int k = 2; // 聚类数

    // 执行K-means聚类算法
    kmeans(data, k);

    return 0;
}