poniedziałek, 19 czerwca 2017
mixed radix fast fourier transform FFT radix-5 * radix-3 * radix-2 * radix-4 * radix-3 for N=360 points example c++
//mixed radix fast fourier transform FFT radix-5 * radix-3 * radix-2 * radix-4 * radix-3 for N=360 points example c++
void fun_fourier_transform_FFT_mixed_radix_5_3_2_4_3_N_360_points(int N,std::complex<double> tab[])
{
const double pi=3.141592653589793238462;
std::complex<double> tab2[4096]={}; // tab2[]==N
std::complex<double> w1[1]={{1,0}};
std::complex<double> w2[1]={{1,0}};
std::complex<double> w3[1]={{1,0}};
std::complex<double> w4[1]={{1,0}};
std::complex<double> w34[1]={{1,0}};
std::complex<double> w40[1]={{1,0}};
std::complex<double> w5[1]={{1,0}};
std::complex<double> w6[1]={{1,0}};
std::complex<double> w50[1]={{1,0}};
std::complex<double> w60[1]={{1,0}};
std::complex<double> w7[1]={{1,0}};
std::complex<double> w11[1]={{1,0}};
std::complex<double> w12[1]={{1,0}};
std::complex<double> w13[1]={{1,0}};
std::complex<double> w14[1]={{1,0}};
std::complex<double> w15[1]={{1,0}};
std::complex<double> w16[1]={{1,0}};
std::complex<double> w17[1]={{1,0}};
std::complex<double> w18[1]={{1,0}};
std::complex<double> w19[1]={{1,0}};
std::complex<double> w20[1]={{1,0}};
std::complex<double> tmp1,tmp2,tmp3,tmp4,tmp11;
double tmp5;
double tmp6;
double tmp7;
double tmp8;
tmp5=2*pi/(N/1);
tmp6=2*pi/(N/1);
tmp7=2*pi/(3/1);
tmp8=2*pi/(5/1);
//radix 3 fundament
w34[0].real()=cos(0*tmp7);
w34[0].imag()=-sin(0*tmp7);
w5[0].real()=cos(1*tmp7);
w5[0].imag()=-sin(1*tmp7);
w6[0].real()=cos(2*tmp7);
w6[0].imag()=-sin(2*tmp7);
w7[0].real()=cos(4*tmp7);
w7[0].imag()=-sin(4*tmp7);
//radix 5 fundament
w11[0].real()=cos(0*tmp8);
w11[0].imag()=-sin(0*tmp8);
w12[0].real()=cos(1*tmp8);
w12[0].imag()=-sin(1*tmp8);
w13[0].real()=cos(2*tmp8);
w13[0].imag()=-sin(2*tmp8);
w14[0].real()=cos(3*tmp8);
w14[0].imag()=-sin(3*tmp8);
w15[0].real()=cos(4*tmp8);
w15[0].imag()=-sin(4*tmp8);
w16[0].real()=cos(6*tmp8);
w16[0].imag()=-sin(6*tmp8);
w17[0].real()=cos(8*tmp8);
w17[0].imag()=-sin(8*tmp8);
w18[0].real()=cos(9*tmp8);
w18[0].imag()=-sin(9*tmp8);
w19[0].real()=cos(12*tmp8);
w19[0].imag()=-sin(12*tmp8);
w20[0].real()=cos(16*tmp8);
w20[0].imag()=-sin(16*tmp8);
//stage 1 radix-5
w1[0].real()=cos(0);
w1[0].imag()=-sin(0);
w2[0].real()=cos(0);
w2[0].imag()=-sin(0);
w3[0].real()=cos(0);
w3[0].imag()=-sin(0);
w4[0].real()=cos(0);
w4[0].imag()=-sin(0);
w40[0].real()=cos(0);
w40[0].imag()=-sin(0);
for(int i=0;i<3*4*2*3;i++)
{
tmp1=w1[0]*tab[i+0];
tmp2=w2[0]*tab[i+1*3*4*2*3];
tmp3=w3[0]*tab[i+2*3*4*2*3];
tmp4=w4[0]*tab[i+3*3*4*2*3];
tmp11=w40[0]*tab[i+4*3*4*2*3];
//radix-5
tab2[i] =w11[0]*tmp1+w11[0]*tmp2+w11[0]*tmp3+w11[0]*tmp4+w11[0]*tmp11;
tab2[i+1*3*4*2*3] =w11[0]*tmp1+w12[0]*tmp2+w13[0]*tmp3+w14[0]*tmp4+w15[0]*tmp11;
tab2[i+2*3*4*2*3] =w11[0]*tmp1+w13[0]*tmp2+w15[0]*tmp3+w16[0]*tmp4+w17[0]*tmp11;
tab2[i+3*3*4*2*3] =w11[0]*tmp1+w14[0]*tmp2+w16[0]*tmp3+w18[0]*tmp4+w19[0]*tmp11;
tab2[i+4*3*4*2*3] =w11[0]*tmp1+w15[0]*tmp2+w17[0]*tmp3+w19[0]*tmp4+w20[0]*tmp11;
}
//stage 2 radix-3
int b=0;
for(int i=0;i<5;i=i+1,b++)
{ if(b>=5){b=0;}
for(int j=0;j<3*4*2;j=j+1)
{
w1[0].real()=cos(b*(0+j)*tmp6);
w1[0].imag()=-sin(b*(0+j)*tmp6);
w2[0].real()=cos(b*(4*2*3+j)*tmp6);
w2[0].imag()=-sin(b*(4*2*3+j)*tmp6);
w3[0].real()=cos(b*(2*4*2*3+j)*tmp6);
w3[0].imag()=-sin(b*(2*4*2*3+j)*tmp6);
tmp1=w1[0]*tab2[i*3*4*2*3+0+j];
tmp2=w2[0]*tab2[i*3*4*2*3+4*2*3+j];
tmp3=w3[0]*tab2[i*3*4*2*3+2*4*2*3+j];
//radix-3
tab[i*3*4*2*3+0+j] =w34[0]*tmp1+w34[0]*tmp2+w34[0]*tmp3;
tab[i*3*4*2*3+4*2*3+j] =w34[0]*tmp1+w5[0]*tmp2+w6[0]*tmp3;
tab[i*3*4*2*3+2*4*2*3+j] =w34[0]*tmp1+w6[0]*tmp2+w7[0]*tmp3;
}
}
;
//stage 3 radix-2
b=0;
for(int i=0;i<5*3;i=i+1,b++)
{
if(b>=3){b=0;}
for(int j=0;j<3*4;j=j+1)
{
w1[0].real()= cos(5*b*(0+j)*tmp5);
w1[0].imag()=-sin(5*b*(0+j)*tmp5);
w2[0].real()= cos(5*b*(1*4*3+j)*tmp5);
w2[0].imag()=-sin(5*b*(1*4*3+j)*tmp5);
tmp1=w1[0]*tab[i*3*4*2+0+j];
tmp2=w2[0]*tab[i*3*4*2+1*4*3+j];
tab2[i*3*4*2+0+j]=tmp1+tmp2;
tab2[i*3*4*2+1*4*3+j]=tmp1-tmp2;
}
}
//stage 4 radix-4
w50[0].real()=0;
w50[0].imag()=-1;
w60[0].real()=0;
w60[0].imag()=1;
b=0;
for(int i=0;i<5*3*2;i=i+1,b++)
{
if(b>=2){b=0;}
for(int j=0;j<3*1;j=j+1)
{
w1[0].real()=cos(5*3*b*(0+j)*tmp5);
w1[0].imag()=-sin(5*3*b*(0+j)*tmp5);
w2[0].real()=cos(5*3*b*(1*3+j)*tmp5);
w2[0].imag()=-sin(5*3*b*(1*3+j)*tmp5);
w3[0].real()=cos(5*3*b*(2*3+j)*tmp5);
w3[0].imag()=-sin(5*3*b*(2*3+j)*tmp5);
w4[0].real()=cos(5*3*b*(3*3+j)*tmp5);
w4[0].imag()=-sin(5*3*b*(3*3+j)*tmp5);
tmp1=w1[0]*tab2[i*3*4+0*3+j];
tmp2=w2[0]*tab2[i*3*4+1*3+j];
tmp3=w3[0]*tab2[i*3*4+2*3+j];
tmp4=w4[0]*tab2[i*3*4+3*3+j];
//radix-4
tab[i*3*4+j] =tmp1+tmp2+tmp3+tmp4;
tab[i*3*4+1*3+j] =tmp1-tmp3+w50[0]*(tmp2-tmp4);
tab[i*3*4+2*3+j] =tmp1-tmp2+tmp3-tmp4;
tab[i*3*4+3*3+j] =tmp1-tmp3+w60[0]*(tmp2-tmp4);
}
}
//stage 5 radix-3
b=0;
for(int i=0;i<5*3*2*4;i=i+1,b++)
{
if(b>=4){b=0;}
for(int j=0;j<1;j=j+1)
{
w1[0].real()=cos(5*3*2*b*(0+j)*tmp6);
w1[0].imag()=-sin(5*3*2*b*(0+j)*tmp6);
w2[0].real()=cos(5*3*2*b*(1+j)*tmp6);
w2[0].imag()=-sin(5*3*2*b*(1+j)*tmp6);
w3[0].real()=cos(5*3*2*b*(2*1+j)*tmp6);
w3[0].imag()=-sin(5*3*2*b*(2*1+j)*tmp6);
tmp1=w1[0]*tab[i*3+0+j];
tmp2=w2[0]*tab[i*3+1+j];
tmp3=w3[0]*tab[i*3+2*1+j];
//radix-3
tab2[i*3+0+j] =w34[0]*tmp1+w34[0]*tmp2+w34[0]*tmp3;
tab2[i*3+1+j] =w34[0]*tmp1+w5[0]*tmp2+w6[0]*tmp3;
tab2[i*3+2*1+j] =w34[0]*tmp1+w6[0]*tmp2+w7[0]*tmp3;
}
}
//new
for(int j=0;j<N;j++)
{
tab[j].real() =tab2[j].real()*2/N;
tab[j].imag() =tab2[j].imag()*2/N;
}
}
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