FFT.rar_class Complex_vc fft_visual c_复数FFT

#include <stdio.h> #include <math.h> #include <complex> //复数运算 #define PI 3.1415926 #define FFTNum 32//1024 //8 #define FFTCodeBit 5//10 //3 //必须要加这句才能用复数运算。。 using namespace std; complex<double> ci(0,1); float signalIn0[FFTNum]; float signalIn[FFTNum]; complex<double> Csignal[FFTNum];//={0,1,2,3,4,5,6,7}; //码位倒置 int CodeInv(int inLocal,int codeBit) { int outLocal=0,tempInL; int cntCodeBit=0; tempInL=inLocal; for (;cntCodeBit<codeBit;) { outLocal<<=1; outLocal+=tempInL%2; cntCodeBit++; tempInL>>=1; } return outLocal; } /*-------------------------------------- |要遍历一遍，而且要多用一倍的空间，不好| --------------------------------------*/ void InvSignal() { int fcnt=0; int invLocal; for (;fcnt<FFTNum;fcnt++) { invLocal=CodeInv(fcnt,FFTCodeBit); signalIn[fcnt]=signalIn0[invLocal]; } } //存入复数数组 void R2CSignal() { int RCcnt=0; for (;RCcnt<FFTNum;RCcnt++) { complex<double> tempC(signalIn[RCcnt],0); Csignal[RCcnt]=tempC; } } //求蝶形运算的W complex<double> wnk(int wN,int wk) { complex<double> w(0,0); double en = -2*PI*wk/wN; w=exp(ci*en); return w; } //sin信号发生函数 void SinCreate(int freq,double Ts) { int scnt=0; for (;scnt<FFTNum;scnt++) { signalIn0[scnt]=sin(2*PI*freq*Ts*scnt); } } //复数取模后存入实数数组 void C2RSignal() { int rcCnt=0; float Re,Im,mode; for (;rcCnt<FFTNum;rcCnt++) { Re=Csignal[rcCnt].real(); Im=Csignal[rcCnt].imag(); mode=sqrt(Re*Re+Im*Im); if(mode<0.00001) mode=0; signalIn[rcCnt]=mode; } } void FFTN2() { int bit=0,k,nn; int Nx,S1L,S2L; complex<double> WNk(0,0),tempX(0,0); InvSignal(); R2CSignal(); //WNk=wnk(8,3);//WNk._Re,WNk._Im实部和虚部 for (;bit<FFTCodeBit;bit++)//bit...0~9 { Nx=FFTNum>>(FFTCodeBit-bit); for (k=0;k<Nx;k++)//0<=k<Nx=FFTNum>>x...x=(FFTCodeBit-bit)---->10~1 { //为WNk赋值 WNk=wnk(FFTNum>>(FFTCodeBit-bit-1),k); for (nn=0;nn<FFTNum/(2*Nx);nn++)//group number=1>>(x-1),每组中有Nx个蝶形运算 { //x1=0..2..4..6--->4gp,Nx=1个W; //x1=0,4..1,5--->2gp,Nx=2个W; //x1=0,1,2,3--->1gp,Nx=4个W; S1L=2*Nx*nn+k; S2L=S1L+(1<<bit); tempX=WNk*Csignal[S2L]; Csignal[S2L]=Csignal[S1L]-tempX; Csignal[S1L]+=tempX;//x2-x1=1,2,4.....1<<bit } } } C2RSignal(); } void main() { SinCreate(50,0.000625); FFTN2(); }