GSL快速傅里叶变换FFT

#include <stdio.h>#include <math.h>#include <gsl/gsl_errno.h>#include <gsl/gsl_fft_complex.h>#pragma comment(lib, "libgsl_d.lib")#pragma comment(lib, "libgslcblas_d.lib")#define REAL(z,i) ((z)[2*(i)])#define IMAG(z,i) ((z)[2*(i)+1])intmain (void){  int i; double data[2*128];  for (i = 0; i < 128; i++)    {       REAL(data,i) = 0.0; IMAG(data,i) = 0.0;    }  REAL(data,0) = 1.0;  for (i = 1; i <= 10; i++)    {       REAL(data,i) = REAL(data,128-i) = 1.0;    }  for (i = 0; i < 128; i++)    {      printf ("%d %e %e\n", i,               REAL(data,i), IMAG(data,i));    }  printf ("\n");  gsl_fft_complex_radix2_forward (data, 1, 128);  for (i = 0; i < 128; i++)    {      printf ("%d %e %e\n", i,               REAL(data,i)/sqrt(128),               IMAG(data,i)/sqrt(128));    }  return 0;}