负数，傅里叶变换，反傅里叶变换

#include <QCoreApplication>
#include "C:\Users\Administrator\Desktop\fftw\fftw-3.3.4-dll32\fftw3.h"
#include "D:\Qt\Eigen\Dense"
#include <stdio.h>
#include <iostream>
#include <complex>

using namespace std;
//  using namespace fftw_complex;
#define N 3

class MyComplex:public complex<double>
{
public:
    MyComplex():complex<double>(0.0, 0.0){m_r=0.0;m_i=0.0;}
    MyComplex(double r, double i):complex<double>(r,i){m_r=r;m_i=i;}
    double getR(){return m_r;}
    double getI(){return m_i;}
private:
    double m_r;
    double m_i;
};

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    //complex<float> www=(1,5);
    MyComplex www(2,4);
    std::cout<<www<<std::endl;
    std::cout<<www.getR()<<std::endl;
    std::cout<<www.getI()<<std::endl;

    int i;
    fftw_complex *in, *out, *result;
    in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N * N);
    out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N * N);
    result = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N * N);
    if (in == NULL || out == NULL)
    {
        printf("ERROR!");
    }
    else
    {
        //for (i=0; i<N*N; i++)
        {
            in[0][0] = 0;     in[0][1] = 0;
            in[1][0] = 1;     in[1][1] = 0;
            in[2][0] = 2;     in[2][1] = 0;
            in[3][0] = 2;     in[3][1] = 0;
            in[4][0] = 3;     in[4][1] = 0;
            in[5][0] = 4;     in[5][1] = 0;
            in[6][0] = 3;     in[6][1] = 0;
            in[7][0] = 2;     in[7][1] = 0;
            in[8][0] = 1;     in[8][1] = 0;
        }
    }
    for (i=0; i<N*N; i++)
    {
        printf("%.6f, %.6fi     ", in[i][0], in[i][1]);
        if(i==2||i==5||i==8)printf("\n");
    }

    //傅里叶变换
    cout << endl;
    fftw_plan p = fftw_plan_dft_2d(N, N, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
    fftw_execute(p);
    for (i=0; i<N*N; i++)
    {
        printf("%.6f, %.6fi     ", out[i][0], out[i][1]);
        if(i==2||i==5||i==8)printf("\n");
    }

    //逆傅里叶变换
    cout << endl;
    fftw_plan pp = fftw_plan_dft_2d(N, N, in, result, FFTW_BACKWARD, FFTW_ESTIMATE);
    fftw_execute(pp);
    for (i=0; i<N*N; i++)
    {
        printf("%.6f, %.6fi     ", result[i][0]/(N*N), result[i][1]/(N*N));
        if(i==2||i==5||i==8)printf("\n");
    }


    fftw_destroy_plan(p);
    fftw_cleanup();
    if (in!=NULL)
        fftw_free(in);
    if (out!=NULL)
        fftw_free(out);
}

 

QT -= gui
CONFIG += c++11 console
CONFIG -= app_bundle
LIBS += -L"C:\Users\Administrator\Desktop\fftw\fftw-3.3.4-dll32" \
    -llibfftw3-3
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp

#include<QCoreApplication>

#include"C:\Users\Administrator\Desktop\fftw\fftw-3.3.4-dll32\fftw3.h"

#include"D:\Qt\Eigen\Dense"

#include<stdio.h>

#include<iostream>

#include<complex>

usingnamespacestd;

//usingnamespacefftw_complex;

#defineN3

classMyComplex:publiccomplex<double>

{

public:

MyComplex():complex<double>(0.0,0.0){m_r=0.0;m_i=0.0;}

MyComplex(doubler,doublei):complex<double>(r,i){m_r=r;m_i=i;}

doublegetR(){returnm_r;}

doublegetI(){returnm_i;}

private:

doublem_r;

doublem_i;

};

intmain(intargc,char*argv[])

{

QCoreApplicationa(argc,argv);

//complex<float>www=(1,5);

MyComplexwww(2,4);

std::cout<<www<<std::endl;

std::cout<<www.getR()<<std::endl;

std::cout<<www.getI()<<std::endl;

inti;

fftw_complex*in,*out,*result;

in=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*N*N);

out=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*N*N);

result=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*N*N);

if(in==NULL||out==NULL)

{

printf("ERROR!");

}

else

{

//for(i=0;i<N*N;i++)

{

in[0][0]=0;in[0][1]=0;

in[1][0]=1;in[1][1]=0;

in[2][0]=2;in[2][1]=0;

in[3][0]=2;in[3][1]=0;

in[4][0]=3;in[4][1]=0;

in[5][0]=4;in[5][1]=0;

in[6][0]=3;in[6][1]=0;

in[7][0]=2;in[7][1]=0;

in[8][0]=1;in[8][1]=0;

}

}

for(i=0;i<N*N;i++)

{

printf("%.6f,%.6fi",in[i][0],in[i][1]);

if(i==2||i==5||i==8)printf("\n");

}

//傅里叶变换

cout<<endl;

fftw_planp=fftw_plan_dft_2d(N,N,in,out,FFTW_FORWARD,FFTW_ESTIMATE);

fftw_execute(p);

for(i=0;i<N*N;i++)

{

printf("%.6f,%.6fi",out[i][0],out[i][1]);

if(i==2||i==5||i==8)printf("\n");

}

//逆傅里叶变换

cout<<endl;

fftw_planpp=fftw_plan_dft_2d(N,N,in,result,FFTW_BACKWARD,FFTW_ESTIMATE);

fftw_execute(pp);

for(i=0;i<N*N;i++)

{

printf("%.6f,%.6fi",result[i][0]/(N*N),result[i][1]/(N*N));

if(i==2||i==5||i==8)printf("\n");

}

fftw_destroy_plan(p);

fftw_cleanup();

if(in!=NULL)

fftw_free(in);

if(out!=NULL)

fftw_free(out);

}