linux的c写傅里叶变化

Linux的C语言实现傅里叶变换的代码如下：

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

#define PI 3.14159265358979323846

void dft(double *x_re, double *x_im, double *y_re, double *y_im, int N) {
    int k, n;
    double w_re, w_im, s_re, s_im;

    for (k = 0; k < N; k++) {
        s_re = 0.0;
        s_im = 0.0;
        for (n = 0; n < N; n++) {
            w_re = cos(2 * PI * n * k / N);
            w_im = -sin(2 * PI * n * k / N);
            s_re += x_re[n] * w_re - x_im[n] * w_im;
            s_im += x_re[n] * w_im + x_im[n] * w_re;
        }
        y_re[k] = s_re;
        y_im[k] = s_im;
    }
}

int main() {
    int N, k;
    double *x_re, *x_im, *y_re, *y_im;

    printf("Enter the number of samples: ");
    scanf("%d", &N);

    x_re = (double *) malloc(N * sizeof(double));
    x_im = (double *) malloc(N * sizeof(double));
    y_re = (double *) malloc(N * sizeof(double));
    y_im = (double *) malloc(N * sizeof(double));

    printf("Enter the samples:\n");
    for (k = 0; k < N; k++) {
        scanf("%lf", &x_re[k]);
        x_im[k] = 0.0;
    }

    dft(x_re, x_im, y_re, y_im, N);

    printf("The DFT result is:\n");
    for (k = 0; k < N; k++) {
        printf("%d: %lf + %lfi\n", k, y_re[k], y_im[k]);
    }

    free(x_re);
    free(x_im);
    free(y_re);
    free(y_im);

    return 0;
}

该程序通过输入采样点的数量和采样值，计算出其傅里叶变换的结果。其中，dft函数是计算离散傅里叶变换的核心函数。程序使用了动态内存分配和释放，以保证程序的灵活性和效率