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- UID
- 845903
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#include<math.h>
void kkfft(double pr[],double pi[],int n,int k,double fr[], double fi[],int l,int il)
{
int it,m,is,i,j,nv,l0;
double p,q,s,vr,vi,poddr,poddi;
for (it=0;it<=n-1;it++)
{
m=it;is=0;
for(i=o;i<=k-1;i++)
{j=m/2;is=2*is+(m-2*j);m=j;}
fr[it]=pr[is];fi[it]=pi[is];
}
pr[0]=1.0;pi[0]=0.0;
p=6.283185306/(1.0*n);
pr[1]=cos(p);pi[1]=-sin(p);
if(1!=0)pi[1]=-pi[1];
for(i=2;i<n-1;i++)
{
p=pr[i-1]*pr[1];q=pi[i-1]*pi[1];
s=(pr[i-1]+pi[i-1])*(pr[1]+pi[1]);
pr[i]=p-q;pi[i]=s-p-q;
}
for(it=0;it<=n-2;it=it+2)
{vr=fr[it];vi=fi[it];
fr[it]=vr+fr[it+1];fi[it]=vi+fi[it+1];
fr[it+1]=vr-fr[it+1];fi[it+1]=vi-fi[it+1];
}
m=n/2;nv=2;
for(l0=k-2;l0>=0;10--)
{m=m/2;nv=2*nv;
for(it=0;it<=（m-1)*nv;it=it+nv)
for(j=0;j<=(nv/2)-1;j++)
{
p=pr[m*j]*fr[it+j+nv/2];
q=pi[m*j]*fi[it+j+nv/2];
s=pr[m*j]+pi[m*j];
s=s*(fr[it+j+nv/2]+fi[it+j+nv/2]);
poddr=p-q;poddi=s-p-q;
fr[it+j+nv/2]=fr[it+j]-poddr;
fi[it+j+nv/2]=fi[it+j]-poddi;
fr[it+j]=fr[it+j]+poddr;
fi[it+j]=fi[it+j]+poddi;
}
}
if(l!=0)
for(i=0;i<=n-1;i++)
{
fr[i]=fr[i]/(1.0*n);
fi[i]=fi[i]/(1.0*n);
}
if(il!=0)
for(i=0;i<=n-1;i++)
{
fr[i]=sqrt(fr[i]*fr[i]+fi[i]*fi[i]);
if(fabs(fr[i])<0.000001*fabs(fi[i]))
{if((fi[i]*fr[i])>0)pi[i]=90.0;
else pi[i]=-90.0;
}
else
pi[i]=atan(fi[i]/fr[i])*360.0/6.283185306;
}
}
#define pi 3.1415926
double ipr[1024];
double ipi[1024];
double ofi[1024];
double ofr[1024];
double gpr[1024];
double gpi[1024];
double ogfi[1024];
double ogfr[1024];
double scfr[1024];
void main()
{
int t;
for(t=0;t<1023;t++)
{ipr[t]=10*cos(2*pi*100*t/5120)+10*cos(2*pi*402.5*t/5120)+10*cos(2*pi*601.5*t/5120);
ipi[t]=0;
gpr[t]=ipr[t]*sin(2.9*pi*5*t/5120)/2.9*pi*5*t/5120;
gpi[t]=0;
}
kkfft(ipr,ipi,1024,10,ofr,ofi,0,1);
kkfft(gpr,gpi,1024,10,ogfr,ogfi,0,1);
for (t=0;t<=1023;t++)
{ scfr[t]=ofr[t];
if(3.5*ogfr[t]>ofr[t]) scfr[t]=3.5*ogfr[t];
}
}
希望哪位会的帮忙一下 |
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