Deconvolution C++

我从 http://rosettacode.org/wiki/Deconvolution/1D#C 那里得到了这个用于一维反卷积的示例代码，它似乎无法正常工作。 尝试构建此项目时，我首先收到此错误"_fft"：非法使用类型"void"。 如果有帮助，这段代码最初是为 C 准备的，我不得不进行一些更改，例如将包含从 complex.h 更改为 complex，并使用命名空间 std。 感谢您的帮助

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <complex>
using namespace std;
double PI;
complex<double> cplx;


void _fft(cplx buf[], cplx out[], int n, int step)
 {
if (step < n) {
    _fft(out, buf, n, step * 2);
    _fft(out + step, buf + step, n, step * 2);
    for (int i = 0; i < n; i += 2 * step) {
        cplx t = cexp(-I * PI * i / n) * out[i + step];
        buf[i / 2]     = out[i] + t;
        buf[(i + n)/2] = out[i] - t;
    }
}
}
void fft(cplx buf[], int n)
{
cplx out[n];
for (int i = 0; i < n; i++) out[i] = buf[i];
_fft(buf, out, n, 1);
}
cplx *pad_two(double g[], int len, int *ns)
{
int n = 1;
if (*ns) n = *ns;
else while (n < len) n *= 2;
cplx *buf = calloc(sizeof(cplx), n);
for (int i = 0; i < len; i++) buf[i] = g[i];
*ns = n;
return buf;
}
void deconv(double g[], int lg, double f[], int lf, double out[]) {
int ns = 0;
cplx *g2 = pad_two(g, lg, &ns);
cplx *f2 = pad_two(f, lf, &ns);
fft(g2, ns);
fft(f2, ns);
cplx h[ns];
for (int i = 0; i < ns; i++) h[i] = g2[i] / f2[i];
fft(h, ns);
for (int i = 0; i >= lf - lg; i--)
    out[-i] = h[(i + ns) % ns]/32;
free(g2);
free(f2);
}
int main()
{
PI = atan2(1,1) * 4;
double g[] = {24,75,71,-34,3,22,-45,23,245,25,52,25,-67,-96,96,31,55,36,29,-43,-7};
double f[] = { -3,-6,-1,8,-6,3,-1,-9,-9,3,-2,5,2,-2,-7,-1 };
double h[] = { -8,-9,-3,-1,-6,7 };
int lg = sizeof(g)/sizeof(double);
int lf = sizeof(f)/sizeof(double);
int lh = sizeof(h)/sizeof(double);
double h2[lh];
double f2[lf];
printf("f[] data is : ");
for (int i = 0; i < lf; i++) printf(" %g", f[i]);
printf("n");
printf("deconv(g, h): ");
deconv(g, lg, h, lh, f2);
for (int i = 0; i < lf; i++) printf(" %g", f2[i]);
printf("n");
printf("h[] data is : ");
for (int i = 0; i < lh; i++) printf(" %g", h[i]);
printf("n");
printf("deconv(g, f): ");
deconv(g, lg, f, lf, h2);
for (int i = 0; i < lh; i++) printf(" %g", h2[i]);
printf("n");
}