帮我写一段可以提取西储大学轴承数据时域特征的代码

以下是可以提取西储大学轴承数据时域特征的代码示例：

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

#define PI 3.14159265358979323846

// 定义函数：计算均值
double mean(double *data, int len) {
    double sum = .;
    for (int i = ; i < len; i++) {
        sum += data[i];
    }
    return sum / len;
}

// 定义函数：计算标准差
double std(double *data, int len) {
    double m = mean(data, len);
    double sum = .;
    for (int i = ; i < len; i++) {
        sum += pow(data[i] - m, 2);
    }
    return sqrt(sum / len);
}

// 定义函数：计算峰值因子
double peak_factor(double *data, int len) {
    double m = mean(data, len);
    double max = data[];
    for (int i = 1; i < len; i++) {
        if (data[i] > max) {
            max = data[i];
        }
    }
    return max / m;
}

// 定义函数：计算脉冲因子
double pulse_factor(double *data, int len) {
    double m = mean(data, len);
    double max = data[];
    for (int i = 1; i < len; i++) {
        if (data[i] > max) {
            max = data[i];
        }
    }
    double rms = std(data, len);
    return max / rms;
}

// 定义函数：计算峰值
double peak(double *data, int len) {
    double max = data[];
    for (int i = 1; i < len; i++) {
        if (data[i] > max) {
            max = data[i];
        }
    }
    return max;
}

// 定义函数：计算有效值
double rms(double *data, int len) {
    double sum = .;
    for (int i = ; i < len; i++) {
        sum += pow(data[i], 2);
    }
    return sqrt(sum / len);
}

// 定义函数：计算峰峰值
double peak_to_peak(double *data, int len) {
    double max = data[];
    double min = data[];
    for (int i = 1; i < len; i++) {
        if (data[i] > max) {
            max = data[i];
        }
        if (data[i] < min) {
            min = data[i];
        }
    }
    return max - min;
}

// 定义函数：计算包络线
void envelope(double *data, int len, double *env) {
    double a = .02; // 指数加权平均数的平滑因子
    double y[len]; // 指数加权平均数
    double max = data[];
    for (int i = 1; i < len; i++) {
        if (data[i] > max) {
            max = data[i];
        }
    }
    for (int i = ; i < len; i++) {
        y[i] = a * data[i] + (1 - a) * y[i-1];
        env[i] = y[i] / max;
    }
}

// 定义函数：计算自相关函数
void autocorr(double *data, int len, double *corr) {
    double m = mean(data, len);
    for (int i = ; i < len; i++) {
        double sum = .;
        for (int j = ; j < len-i; j++) {
            sum += (data[j] - m) * (data[j+i] - m);
        }
        corr[i] = sum / (len - i);
    }
}

// 定义函数：计算功率谱密度
void psd(double *data, int len, double *freq, double *psd) {
    double dt = .001; // 采样时间间隔
    double df = 1. / (len * dt); // 频率分辨率
    for (int i = ; i < len; i++) {
        double sum = .;
        for (int j = ; j < len; j++) {
            sum += data[j] * cos(2 * PI * i * j / len);
        }
        freq[i] = i * df;
        psd[i] = sum * sum / (len * len);
    }
}

int main() {
    // 读取数据
    FILE *fp = fopen("data.txt", "r");
    if (fp == NULL) {
        printf("Failed to open file.\n");
        return 1;
    }
    int len = 100;
    double data[len];
    for (int i = ; i < len; i++) {
        fscanf(fp, "%lf", &data[i]);
    }
    fclose(fp);

    // 计算时域特征
    double env[len];
    envelope(data, len, env);
    double corr[len];
    autocorr(data, len, corr);
    double freq[len];
    double psd[len];
    psd(data, len, freq, psd);
    double m = mean(data, len);
    double s = std(data, len);
    double pf = peak_factor(data, len);
    double pu = pulse_factor(data, len);
    double p = peak(data, len);
    double r = rms(data, len);
    double pp = peak_to_peak(data, len);

    // 输出结果
    printf("均值：%lf\n", m);
    printf("标准差：%lf\n", s);
    printf("峰值因子：%lf\n", pf);
    printf("脉冲因子：%lf\n", pu);
    printf("峰值：%lf\n", p);
    printf("有效值：%lf\n", r);
    printf("峰峰值：%lf\n", pp);
    printf("包络线：\n");
    for (int i = ; i < len; i++) {
        printf("%lf ", env[i]);
    }
    printf("\n");
    printf("自相关函数：\n");
    for (int i = ; i < len; i++) {
        printf("%lf ", corr[i]);
    }
    printf("\n");
    printf("功率谱密度：\n");
    for (int i = ; i < len; i++) {
        printf("%lf %lf\n", freq[i], psd[i]);
    }

    return ;
}