克里金插值算法 c++

以下是C++实现克里金插值的代码示例：

#include <iostream>
#include <fstream>
#include <cmath>
#include <vector>
#include <algorithm>

using namespace std;

// 定义点的结构体
struct Point {
    double x, y, z;
};

// 定义距离的结构体
struct Distance {
    int index;
    double distance;
};

// 计算两点之间的距离
double calcDistance(Point p1, Point p2) {
    return sqrt(pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2));
}

// 计算反距离加权插值
double calcIDW(vector<Point> points, Point p, int k) {
    double numerator = 0.0;
    double denominator = 0.0;
    vector<Distance> distances;
    for (int i = 0; i < points.size(); i++) {
        double distance = calcDistance(points[i], p);
        distances.push_back({i, distance});
    }
    sort(distances.begin(), distances.end(), [](Distance d1, Distance d2) {
        return d1.distance < d2.distance;
    });
    for (int i = 0; i < k; i++) {
        int index = distances[i].index;
        double distance = distances[i].distance;
        numerator += points[index].z / pow(distance, 2);
        denominator += 1 / pow(distance, 2);
    }
    return numerator / denominator;
}

// 计算最邻近点插值
double calcNN(vector<Point> points, Point p) {
    double minDistance = calcDistance(points[0], p);
    double z = points[0].z;
    for (int i = 1; i < points.size(); i++) {
        double distance = calcDistance(points[i], p);
        if (distance < minDistance) {
            minDistance = distance;
            z = points[i].z;
        }
    }
    return z;
}

int main() {
    // 读取数据
    ifstream fin("data.txt");
    vector<Point> points;
    double x, y, z;
    while (fin >> x >> y >> z) {
        points.push_back({x, y, z});
    }
    fin.close();

    // 计算插值
    Point p = {1.0, 1.0, 0.0};
    int k = 3;
    double idw = calcIDW(points, p, k);
    double nn = calcNN(points, p);

    // 输出结果
    cout << "反距离加权插值：" << idw << endl;
    cout << "最邻近点插值：" << nn << endl;

    return 0;
}