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=L[it];
fr[it]=vr+fr[it+1]; L[it]=vi+L[it+1];
fr[it+1]=vr-fr[it+1]; L[it+1]=vi-L[it+1];
}
m=n/2; nv=2;
for(l0=k-2; l0>=0; l0--)
{
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]*L[it+j+nv/2];
s=pr[m*j]+pi[m*j];
s=s*(fr[it+j+nv/2]+L[it+j+nv/2]);
poddr=p-q; poddi=s-p-q;
fr[it+j+nv/2]=fr[it+j]-poddr;
L[it+j+nv/2]=L[it+j]-poddi;
fr[it+j]=fr[it+j]+poddr;
L[it+j]=L[it+j]+poddi;
}
}
if(l!=0)
for(i=0; i<=n-1; i++)
{
fr[i]=fr[i]/(1.0*n);
L[i]=L[i]/(1.0*n);
}
if(il!=0)
for(i=0; i<=n-1; i++)
{
pr[i]=sqrt(fr[i]*fr[i]+L[i]*L[i]);
if(fabs(fr[i])<0.000001*fabs(L[i]))
{
if((L[i]*fr[i])>0) pi[i]=90.0;
elsepi[i]=-90.0;
}
else
pi[i]=atan(L[i]/fr[i])*360.0/6.283185306;
}
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