C语言最小二乘法怎么写

这是一个使用C语言实现最小二乘法的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define MAX_POINTS 100

double x[MAX_POINTS];
double y[MAX_POINTS];

double sum(double *data, int n) {
    double s = 0.0;
    for (int i = 0; i < n; i++) {
        s += data[i];
    }
    return s;
}

double mean(double *data, int n) {
    return sum(data, n) / n;
}

double covariance(double *x, double *y, int n) {
    double mx = mean(x, n);
    double my = mean(y, n);
    double s = 0.0;
    for (int i = 0; i < n; i++) {
        s += (x[i] - mx) * (y[i] - my);
    }
    return s;
}

double variance(double *data, int n) {
    double m = mean(data, n);
    double s = 0.0;
    for (int i = 0; i < n; i++) {
        s += (data[i] - m) * (data[i] - m);
    }
    return s;
}

double slope(double *x, double *y, int n) {
    return covariance(x, y, n) / variance(x, n);
}

double intercept(double *x, double *y, int n) {
    double m = mean(y, n) - slope(x, y, n) * mean(x, n);
    return m;
}

void print_points(double *x, double *y, int n) {
    for (int i = 0; i < n; i++) {
        printf("(%lf, %lf)\n", x[i], y[i]);
    }
}

int main() {
    int n;
    printf("Enter number of points (max %d): ", MAX_POINTS);
    scanf("%d", &n);
    if (n <= 0 || n > MAX_POINTS) {
        printf("Invalid number of points.\n");
        return 1;
    }
    for (int i = 0; i < n; i++) {
        printf("Enter point %d (x y): ", i + 1);
        scanf("%lf %lf", &x[i], &y[i]);
    }
    double m = slope(x, y, n);
    double b = intercept(x, y, n);
    printf("Linear equation: y = %lfx + %lf\n", m, b);
    return 0;
}

该程序首先提示用户输入点的数量，然后依次提示用户输入每个点的坐标。接下来，它计算最小二乘线的斜率和截距，并输出线性方程。