Подключение библиотеки fftw. Преобразование Фурье.

       typedef void __cdecl(*dll_func)(void);
 
        dll_func Func = NULL;
        HMODULE hDLL = LoadLibrary("libfftw3-3.dll");
        if(!hDLL)
                cout << "Impossible to load library" << endl;
        else    cout << "success load lib" << endl;
 
        Func = (dll_func)GetProcAddress(hDLL, "fftw_plan_r2r_1d");
        if(!Func)
                cout << "Impossible to find function" << endl;
        else    cout << "success find function" << endl;

typedef fftw_plan
     (__cdecl *DLL_fftw_plan_r2r_1d)(int n, double *in, double *out, fftw_r2r_kind kind, unsigned flags);
 
//...

#include <complex>
#include "fftw3.h"
#pragma comment (lib,"libfftw3-3.dll.lib")
#pragma comment (lib,"libfftw3f-3.dll.lib")
#pragma comment (lib,"libfftw3l-3.dll.lib")
// ---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1* Form1;
 
// ---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner)
{
}
 
// ---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject* Sender)
{
    int N= 10;
 
    std::complex<double> *in= new std::complex<double>[N];
    std::complex<double> *out= new std::complex<double>[N];
 
    fftw_plan p= fftw_plan_dft_1d(N, reinterpret_cast<fftw_complex*>(in),
            reinterpret_cast<fftw_complex*>(out), FFTW_FORWARD, FFTW_ESTIMATE);
    double pi= acos(-1.);
    for (int i= 0; i< N; i++)
        in[i]= sin(2* pi* 0.2* i);
 
    fftw_execute(p);
 
    for (int i= 0; i< N; i++)
    {
        RichEdit1->Lines->Add(  String(out[i].real())+" + "+
                                                        String(out[i].imag())+"j"
                                                    );
    }
 
    fftw_destroy_plan(p);
    delete[]in;
    delete[]out;
}
// ---------------------------------------------------------------------------