mirror of
https://gitlab.com/libeigen/eigen.git
synced 2024-12-15 07:10:37 +08:00
refactored ei_kissfft_impl to maintain a cache of cpx fft plans
This commit is contained in:
Mark Borgerding
parent
210092d16c
commit
03ed6f9bfb
@ -24,21 +24,279 @@
|
||||
|
||||
#include <complex>
|
||||
#include <vector>
|
||||
#include <map>
|
||||
|
||||
namespace Eigen {
|
||||
|
||||
template <typename _Scalar>
|
||||
struct ei_kiss_cpx_fft
|
||||
{
|
||||
typedef _Scalar Scalar;
|
||||
typedef std::complex<Scalar> Complex;
|
||||
std::vector<Complex> m_twiddles;
|
||||
std::vector<int> m_stageRadix;
|
||||
std::vector<int> m_stageRemainder;
|
||||
bool m_inverse;
|
||||
|
||||
ei_kiss_cpx_fft() { }
|
||||
|
||||
void make_twiddles(int nfft,bool inverse)
|
||||
{
|
||||
m_inverse = inverse;
|
||||
m_twiddles.resize(nfft);
|
||||
Scalar phinc = (inverse?2:-2)* acos( (Scalar) -1) / nfft;
|
||||
for (int i=0;i<nfft;++i)
|
||||
m_twiddles[i] = exp( Complex(0,i*phinc) );
|
||||
}
|
||||
|
||||
void invert()
|
||||
{
|
||||
m_inverse = !m_inverse;
|
||||
for ( size_t i=0;i<m_twiddles.size() ;++i)
|
||||
m_twiddles[i] = conj( m_twiddles[i] );
|
||||
}
|
||||
|
||||
void factorize(int nfft)
|
||||
{
|
||||
if (m_stageRadix.size()==0 || m_stageRadix[0] * m_stageRemainder[0] != nfft)
|
||||
{
|
||||
m_stageRadix.resize(0);
|
||||
m_stageRemainder.resize(0);
|
||||
//factorize
|
||||
//start factoring out 4's, then 2's, then 3,5,7,9,...
|
||||
int n= nfft;
|
||||
int p=4;
|
||||
do {
|
||||
while (n % p) {
|
||||
switch (p) {
|
||||
case 4: p = 2; break;
|
||||
case 2: p = 3; break;
|
||||
default: p += 2; break;
|
||||
}
|
||||
if (p*p>n)
|
||||
p=n;// impossible to have a factor > sqrt(n)
|
||||
}
|
||||
n /= p;
|
||||
m_stageRadix.push_back(p);
|
||||
m_stageRemainder.push_back(n);
|
||||
}while(n>1);
|
||||
}
|
||||
}
|
||||
|
||||
template <typename _Src>
|
||||
void work( int stage,Complex * xout, const _Src * xin, size_t fstride,size_t in_stride)
|
||||
{
|
||||
int p = m_stageRadix[stage];
|
||||
int m = m_stageRemainder[stage];
|
||||
Complex * Fout_beg = xout;
|
||||
Complex * Fout_end = xout + p*m;
|
||||
|
||||
if (m>1) {
|
||||
do{
|
||||
// recursive call:
|
||||
// DFT of size m*p performed by doing
|
||||
// p instances of smaller DFTs of size m,
|
||||
// each one takes a decimated version of the input
|
||||
work(stage+1, xout , xin, fstride*p,in_stride);
|
||||
xin += fstride*in_stride;
|
||||
}while( (xout += m) != Fout_end );
|
||||
}else{
|
||||
do{
|
||||
*xout = *xin;
|
||||
xin += fstride*in_stride;
|
||||
}while(++xout != Fout_end );
|
||||
}
|
||||
xout=Fout_beg;
|
||||
|
||||
// recombine the p smaller DFTs
|
||||
switch (p) {
|
||||
case 2: bfly2(xout,fstride,m); break;
|
||||
case 3: bfly3(xout,fstride,m); break;
|
||||
case 4: bfly4(xout,fstride,m); break;
|
||||
case 5: bfly5(xout,fstride,m); break;
|
||||
default: bfly_generic(xout,fstride,m,p); break;
|
||||
}
|
||||
}
|
||||
|
||||
void bfly2( Complex * Fout, const size_t fstride, int m)
|
||||
{
|
||||
for (int k=0;k<m;++k) {
|
||||
Complex t = Fout[m+k] * m_twiddles[k*fstride];
|
||||
Fout[m+k] = Fout[k] - t;
|
||||
Fout[k] += t;
|
||||
}
|
||||
}
|
||||
|
||||
void bfly4( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
Complex scratch[6];
|
||||
int negative_if_inverse = m_inverse * -2 +1;
|
||||
for (size_t k=0;k<m;++k) {
|
||||
scratch[0] = Fout[k+m] * m_twiddles[k*fstride];
|
||||
scratch[1] = Fout[k+2*m] * m_twiddles[k*fstride*2];
|
||||
scratch[2] = Fout[k+3*m] * m_twiddles[k*fstride*3];
|
||||
scratch[5] = Fout[k] - scratch[1];
|
||||
|
||||
Fout[k] += scratch[1];
|
||||
scratch[3] = scratch[0] + scratch[2];
|
||||
scratch[4] = scratch[0] - scratch[2];
|
||||
scratch[4] = Complex( scratch[4].imag()*negative_if_inverse , -scratch[4].real()* negative_if_inverse );
|
||||
|
||||
Fout[k+2*m] = Fout[k] - scratch[3];
|
||||
Fout[k] += scratch[3];
|
||||
Fout[k+m] = scratch[5] + scratch[4];
|
||||
Fout[k+3*m] = scratch[5] - scratch[4];
|
||||
}
|
||||
}
|
||||
|
||||
void bfly3( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
size_t k=m;
|
||||
const size_t m2 = 2*m;
|
||||
Complex *tw1,*tw2;
|
||||
Complex scratch[5];
|
||||
Complex epi3;
|
||||
epi3 = m_twiddles[fstride*m];
|
||||
|
||||
tw1=tw2=&m_twiddles[0];
|
||||
|
||||
do{
|
||||
scratch[1]=Fout[m] * *tw1;
|
||||
scratch[2]=Fout[m2] * *tw2;
|
||||
|
||||
scratch[3]=scratch[1]+scratch[2];
|
||||
scratch[0]=scratch[1]-scratch[2];
|
||||
tw1 += fstride;
|
||||
tw2 += fstride*2;
|
||||
Fout[m] = Complex( Fout->real() - .5*scratch[3].real() , Fout->imag() - .5*scratch[3].imag() );
|
||||
scratch[0] *= epi3.imag();
|
||||
*Fout += scratch[3];
|
||||
Fout[m2] = Complex( Fout[m].real() + scratch[0].imag() , Fout[m].imag() - scratch[0].real() );
|
||||
Fout[m] += Complex( -scratch[0].imag(),scratch[0].real() );
|
||||
++Fout;
|
||||
}while(--k);
|
||||
}
|
||||
|
||||
void bfly5( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
Complex *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
|
||||
size_t u;
|
||||
Complex scratch[13];
|
||||
Complex * twiddles = &m_twiddles[0];
|
||||
Complex *tw;
|
||||
Complex ya,yb;
|
||||
ya = twiddles[fstride*m];
|
||||
yb = twiddles[fstride*2*m];
|
||||
|
||||
Fout0=Fout;
|
||||
Fout1=Fout0+m;
|
||||
Fout2=Fout0+2*m;
|
||||
Fout3=Fout0+3*m;
|
||||
Fout4=Fout0+4*m;
|
||||
|
||||
tw=twiddles;
|
||||
for ( u=0; u<m; ++u ) {
|
||||
scratch[0] = *Fout0;
|
||||
|
||||
scratch[1] = *Fout1 * tw[u*fstride];
|
||||
scratch[2] = *Fout2 * tw[2*u*fstride];
|
||||
scratch[3] = *Fout3 * tw[3*u*fstride];
|
||||
scratch[4] = *Fout4 * tw[4*u*fstride];
|
||||
|
||||
scratch[7] = scratch[1] + scratch[4];
|
||||
scratch[10] = scratch[1] - scratch[4];
|
||||
scratch[8] = scratch[2] + scratch[3];
|
||||
scratch[9] = scratch[2] - scratch[3];
|
||||
|
||||
*Fout0 += scratch[7];
|
||||
*Fout0 += scratch[8];
|
||||
|
||||
scratch[5] = scratch[0] + Complex(
|
||||
(scratch[7].real()*ya.real() ) + (scratch[8].real() *yb.real() ),
|
||||
(scratch[7].imag()*ya.real()) + (scratch[8].imag()*yb.real())
|
||||
);
|
||||
|
||||
scratch[6] = Complex(
|
||||
(scratch[10].imag()*ya.imag()) + (scratch[9].imag()*yb.imag()),
|
||||
-(scratch[10].real()*ya.imag()) - (scratch[9].real()*yb.imag())
|
||||
);
|
||||
|
||||
*Fout1 = scratch[5] - scratch[6];
|
||||
*Fout4 = scratch[5] + scratch[6];
|
||||
|
||||
scratch[11] = scratch[0] +
|
||||
Complex(
|
||||
(scratch[7].real()*yb.real()) + (scratch[8].real()*ya.real()),
|
||||
(scratch[7].imag()*yb.real()) + (scratch[8].imag()*ya.real())
|
||||
);
|
||||
|
||||
scratch[12] = Complex(
|
||||
-(scratch[10].imag()*yb.imag()) + (scratch[9].imag()*ya.imag()),
|
||||
(scratch[10].real()*yb.imag()) - (scratch[9].real()*ya.imag())
|
||||
);
|
||||
|
||||
*Fout2=scratch[11]+scratch[12];
|
||||
*Fout3=scratch[11]-scratch[12];
|
||||
|
||||
++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
|
||||
}
|
||||
}
|
||||
|
||||
/* perform the butterfly for one stage of a mixed radix FFT */
|
||||
void bfly_generic(
|
||||
Complex * Fout,
|
||||
const size_t fstride,
|
||||
int m,
|
||||
int p
|
||||
)
|
||||
{
|
||||
int u,k,q1,q;
|
||||
Complex * twiddles = &m_twiddles[0];
|
||||
Complex t;
|
||||
int Norig = m_twiddles.size();
|
||||
Complex * scratchbuf = (Complex*)alloca(p*sizeof(Complex) );
|
||||
|
||||
for ( u=0; u<m; ++u ) {
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
scratchbuf[q1] = Fout[ k ];
|
||||
k += m;
|
||||
}
|
||||
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
int twidx=0;
|
||||
Fout[ k ] = scratchbuf[0];
|
||||
for (q=1;q<p;++q ) {
|
||||
twidx += fstride * k;
|
||||
if (twidx>=Norig) twidx-=Norig;
|
||||
t=scratchbuf[q] * twiddles[twidx];
|
||||
Fout[ k ] += t;
|
||||
}
|
||||
k += m;
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
template <typename _Scalar>
|
||||
struct ei_kissfft_impl
|
||||
{
|
||||
typedef _Scalar Scalar;
|
||||
typedef std::complex<Scalar> Complex;
|
||||
ei_kissfft_impl() : m_nfft(0) {}
|
||||
ei_kissfft_impl() {}
|
||||
|
||||
void clear()
|
||||
{
|
||||
m_plans.clear();
|
||||
m_realTwiddles.clear();
|
||||
}
|
||||
|
||||
template <typename _Src>
|
||||
void fwd( Complex * dst,const _Src *src,int nfft)
|
||||
{
|
||||
prepare(nfft,false);
|
||||
work(0, dst, src, 1,1);
|
||||
get_plan(nfft,false).work(0, dst, src, 1,1);
|
||||
}
|
||||
|
||||
// real-to-complex forward FFT
|
||||
@ -47,16 +305,16 @@ namespace Eigen {
|
||||
// then fill in the conjugate symmetric half
|
||||
void fwd( Complex * dst,const Scalar * src,int nfft)
|
||||
{
|
||||
if ( nfft&1 ) {
|
||||
if ( nfft&3 ) {
|
||||
// use generic mode for odd
|
||||
prepare(nfft,false);
|
||||
work(0, dst, src, 1,1);
|
||||
get_plan(nfft,false).work(0, dst, src, 1,1);
|
||||
}else{
|
||||
int ncfft = nfft>>1;
|
||||
int ncfft2 = nfft>>2;
|
||||
Complex * rtw = real_twiddles(ncfft2);
|
||||
|
||||
// use optimized mode for even real
|
||||
fwd( dst, reinterpret_cast<const Complex*> (src),ncfft);
|
||||
make_real_twiddles(nfft);
|
||||
fwd( dst, reinterpret_cast<const Complex*> (src), ncfft);
|
||||
Complex dc = dst[0].real() + dst[0].imag();
|
||||
Complex nyquist = dst[0].real() - dst[0].imag();
|
||||
int k;
|
||||
@ -65,8 +323,7 @@ namespace Eigen {
|
||||
Complex fpnk = conj(dst[ncfft-k]);
|
||||
Complex f1k = fpk + fpnk;
|
||||
Complex f2k = fpk - fpnk;
|
||||
//Complex tw = f2k * exp( Complex(0,-3.14159265358979323846264338327 * ((double) (k) / ncfft + .5) ) );
|
||||
Complex tw= f2k * m_realTwiddles[k-1];
|
||||
Complex tw= f2k * rtw[k-1];
|
||||
|
||||
dst[k] = (f1k + tw) * Scalar(.5);
|
||||
dst[ncfft-k] = conj(f1k -tw)*Scalar(.5);
|
||||
@ -94,304 +351,67 @@ namespace Eigen {
|
||||
|
||||
void inv(Complex * dst,const Complex *src,int nfft)
|
||||
{
|
||||
prepare(nfft,true);
|
||||
work(0, dst, src, 1,1);
|
||||
scale(dst, Scalar(1)/m_nfft );
|
||||
}
|
||||
|
||||
void prepare(int nfft,bool inverse)
|
||||
{
|
||||
make_twiddles(nfft,inverse);
|
||||
factorize(nfft);
|
||||
}
|
||||
|
||||
void make_real_twiddles(int nfft)
|
||||
{
|
||||
int ncfft2 = nfft>>2;
|
||||
if ( m_realTwiddles.size() != ncfft2) {
|
||||
m_realTwiddles.resize(ncfft2);
|
||||
int ncfft= nfft>>1;
|
||||
for (int k=1;k<=ncfft2;++k)
|
||||
m_realTwiddles[k-1] = exp( Complex(0,-3.14159265358979323846264338327 * ((double) (k) / ncfft + .5) ) );
|
||||
}
|
||||
}
|
||||
|
||||
void make_twiddles(int nfft,bool inverse)
|
||||
{
|
||||
if ( m_twiddles.size() == nfft) {
|
||||
// reuse the twiddles, conjugate if necessary
|
||||
if (inverse != m_inverse)
|
||||
for (int i=0;i<nfft;++i)
|
||||
m_twiddles[i] = conj( m_twiddles[i] );
|
||||
}else{
|
||||
m_twiddles.resize(nfft);
|
||||
Scalar phinc = (inverse?2:-2)* acos( (Scalar) -1) / nfft;
|
||||
for (int i=0;i<nfft;++i)
|
||||
m_twiddles[i] = exp( Complex(0,i*phinc) );
|
||||
}
|
||||
m_inverse = inverse;
|
||||
}
|
||||
|
||||
void factorize(int nfft)
|
||||
{
|
||||
if (m_stageRadix.size()==0 || m_stageRadix[0] * m_stageRemainder[0] != nfft)
|
||||
{
|
||||
m_stageRadix.resize(0);
|
||||
m_stageRemainder.resize(0);
|
||||
//factorize
|
||||
//start factoring out 4's, then 2's, then 3,5,7,9,...
|
||||
int n= nfft;
|
||||
int p=4;
|
||||
do {
|
||||
while (n % p) {
|
||||
switch (p) {
|
||||
case 4: p = 2; break;
|
||||
case 2: p = 3; break;
|
||||
default: p += 2; break;
|
||||
}
|
||||
if (p*p>n)
|
||||
p=n;// impossible to have a factor > sqrt(n)
|
||||
}
|
||||
n /= p;
|
||||
m_stageRadix.push_back(p);
|
||||
m_stageRemainder.push_back(n);
|
||||
}while(n>1);
|
||||
}
|
||||
m_nfft = nfft;
|
||||
}
|
||||
|
||||
void scale(Complex *dst,Scalar s)
|
||||
{
|
||||
for (int k=0;k<m_nfft;++k)
|
||||
dst[k] *= s;
|
||||
get_plan(nfft,true).work(0, dst, src, 1,1);
|
||||
scale(dst, nfft, Scalar(1)/nfft );
|
||||
}
|
||||
|
||||
private:
|
||||
|
||||
template <typename _Src>
|
||||
void work( int stage,Complex * xout, const _Src * xin, size_t fstride,size_t in_stride)
|
||||
typedef ei_kiss_cpx_fft<Scalar> PlanData;
|
||||
|
||||
typedef std::map<int,PlanData> PlanMap;
|
||||
PlanMap m_plans;
|
||||
std::map<int, std::vector<Complex> > m_realTwiddles;
|
||||
|
||||
int PlanKey(int nfft,bool isinverse) const { return (nfft<<1) | isinverse; }
|
||||
|
||||
PlanData & get_plan(int nfft,bool inverse)
|
||||
{
|
||||
int p = m_stageRadix[stage];
|
||||
int m = m_stageRemainder[stage];
|
||||
Complex * Fout_beg = xout;
|
||||
Complex * Fout_end = xout + p*m;
|
||||
|
||||
if (m>1) {
|
||||
do{
|
||||
// recursive call:
|
||||
// DFT of size m*p performed by doing
|
||||
// p instances of smaller DFTs of size m,
|
||||
// each one takes a decimated version of the input
|
||||
work(stage+1, xout , xin, fstride*p,in_stride);
|
||||
xin += fstride*in_stride;
|
||||
}while( (xout += m) != Fout_end );
|
||||
}else{
|
||||
do{
|
||||
*xout = *xin;
|
||||
xin += fstride*in_stride;
|
||||
}while(++xout != Fout_end );
|
||||
}
|
||||
xout=Fout_beg;
|
||||
|
||||
// recombine the p smaller DFTs
|
||||
switch (p) {
|
||||
case 2: bfly2(xout,fstride,m); break;
|
||||
case 3: bfly3(xout,fstride,m); break;
|
||||
case 4: bfly4(xout,fstride,m); break;
|
||||
case 5: bfly5(xout,fstride,m); break;
|
||||
default: bfly_generic(xout,fstride,m,p); break;
|
||||
}
|
||||
}
|
||||
|
||||
void bfly2( Complex * Fout, const size_t fstride, int m)
|
||||
{
|
||||
for (int k=0;k<m;++k) {
|
||||
Complex t = Fout[m+k] * m_twiddles[k*fstride];
|
||||
Fout[m+k] = Fout[k] - t;
|
||||
Fout[k] += t;
|
||||
}
|
||||
}
|
||||
|
||||
void bfly4( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
Complex scratch[6];
|
||||
int negative_if_inverse = m_inverse * -2 +1;
|
||||
for (size_t k=0;k<m;++k) {
|
||||
scratch[0] = Fout[k+m] * m_twiddles[k*fstride];
|
||||
scratch[1] = Fout[k+2*m] * m_twiddles[k*fstride*2];
|
||||
scratch[2] = Fout[k+3*m] * m_twiddles[k*fstride*3];
|
||||
scratch[5] = Fout[k] - scratch[1];
|
||||
|
||||
Fout[k] += scratch[1];
|
||||
scratch[3] = scratch[0] + scratch[2];
|
||||
scratch[4] = scratch[0] - scratch[2];
|
||||
scratch[4] = Complex( scratch[4].imag()*negative_if_inverse , -scratch[4].real()* negative_if_inverse );
|
||||
|
||||
Fout[k+2*m] = Fout[k] - scratch[3];
|
||||
Fout[k] += scratch[3];
|
||||
Fout[k+m] = scratch[5] + scratch[4];
|
||||
Fout[k+3*m] = scratch[5] - scratch[4];
|
||||
}
|
||||
}
|
||||
|
||||
void bfly3( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
size_t k=m;
|
||||
const size_t m2 = 2*m;
|
||||
Complex *tw1,*tw2;
|
||||
Complex scratch[5];
|
||||
Complex epi3;
|
||||
epi3 = m_twiddles[fstride*m];
|
||||
|
||||
tw1=tw2=&m_twiddles[0];
|
||||
|
||||
do{
|
||||
scratch[1]=Fout[m] * *tw1;
|
||||
scratch[2]=Fout[m2] * *tw2;
|
||||
|
||||
scratch[3]=scratch[1]+scratch[2];
|
||||
scratch[0]=scratch[1]-scratch[2];
|
||||
tw1 += fstride;
|
||||
tw2 += fstride*2;
|
||||
Fout[m] = Complex( Fout->real() - .5*scratch[3].real() , Fout->imag() - .5*scratch[3].imag() );
|
||||
scratch[0] *= epi3.imag();
|
||||
*Fout += scratch[3];
|
||||
Fout[m2] = Complex( Fout[m].real() + scratch[0].imag() , Fout[m].imag() - scratch[0].real() );
|
||||
Fout[m] += Complex( -scratch[0].imag(),scratch[0].real() );
|
||||
++Fout;
|
||||
}while(--k);
|
||||
}
|
||||
|
||||
void bfly5( Complex * Fout, const size_t fstride, const size_t m)
|
||||
{
|
||||
Complex *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
|
||||
size_t u;
|
||||
Complex scratch[13];
|
||||
Complex * twiddles = &m_twiddles[0];
|
||||
Complex *tw;
|
||||
Complex ya,yb;
|
||||
ya = twiddles[fstride*m];
|
||||
yb = twiddles[fstride*2*m];
|
||||
|
||||
Fout0=Fout;
|
||||
Fout1=Fout0+m;
|
||||
Fout2=Fout0+2*m;
|
||||
Fout3=Fout0+3*m;
|
||||
Fout4=Fout0+4*m;
|
||||
|
||||
tw=twiddles;
|
||||
for ( u=0; u<m; ++u ) {
|
||||
scratch[0] = *Fout0;
|
||||
|
||||
scratch[1] = *Fout1 * tw[u*fstride];
|
||||
scratch[2] = *Fout2 * tw[2*u*fstride];
|
||||
scratch[3] = *Fout3 * tw[3*u*fstride];
|
||||
scratch[4] = *Fout4 * tw[4*u*fstride];
|
||||
|
||||
scratch[7] = scratch[1] + scratch[4];
|
||||
scratch[10] = scratch[1] - scratch[4];
|
||||
scratch[8] = scratch[2] + scratch[3];
|
||||
scratch[9] = scratch[2] - scratch[3];
|
||||
|
||||
*Fout0 += scratch[7];
|
||||
*Fout0 += scratch[8];
|
||||
|
||||
scratch[5] = scratch[0] + Complex(
|
||||
(scratch[7].real()*ya.real() ) + (scratch[8].real() *yb.real() ),
|
||||
(scratch[7].imag()*ya.real()) + (scratch[8].imag()*yb.real())
|
||||
);
|
||||
|
||||
scratch[6] = Complex(
|
||||
(scratch[10].imag()*ya.imag()) + (scratch[9].imag()*yb.imag()),
|
||||
-(scratch[10].real()*ya.imag()) - (scratch[9].real()*yb.imag())
|
||||
);
|
||||
|
||||
*Fout1 = scratch[5] - scratch[6];
|
||||
*Fout4 = scratch[5] + scratch[6];
|
||||
|
||||
scratch[11] = scratch[0] +
|
||||
Complex(
|
||||
(scratch[7].real()*yb.real()) + (scratch[8].real()*ya.real()),
|
||||
(scratch[7].imag()*yb.real()) + (scratch[8].imag()*ya.real())
|
||||
);
|
||||
|
||||
scratch[12] = Complex(
|
||||
-(scratch[10].imag()*yb.imag()) + (scratch[9].imag()*ya.imag()),
|
||||
(scratch[10].real()*yb.imag()) - (scratch[9].real()*ya.imag())
|
||||
);
|
||||
|
||||
*Fout2=scratch[11]+scratch[12];
|
||||
*Fout3=scratch[11]-scratch[12];
|
||||
|
||||
++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
|
||||
}
|
||||
}
|
||||
|
||||
/* perform the butterfly for one stage of a mixed radix FFT */
|
||||
void bfly_generic(
|
||||
Complex * Fout,
|
||||
const size_t fstride,
|
||||
int m,
|
||||
int p
|
||||
)
|
||||
{
|
||||
int u,k,q1,q;
|
||||
Complex * twiddles = &m_twiddles[0];
|
||||
Complex t;
|
||||
int Norig = m_nfft;
|
||||
Complex * scratchbuf = (Complex*)alloca(p*sizeof(Complex) );
|
||||
|
||||
for ( u=0; u<m; ++u ) {
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
scratchbuf[q1] = Fout[ k ];
|
||||
k += m;
|
||||
/*
|
||||
* for some reason this does not work
|
||||
*
|
||||
typedef typename std::map<int,PlanData>::iterator MapIt;
|
||||
MapIt it;
|
||||
it = m_plans.find( PlanKey(nfft,inverse) );
|
||||
if (it == m_plans.end() ) {
|
||||
// create new entry
|
||||
it = m_plans.insert( make_pair( PlanKey(nfft,inverse) , PlanData() ) );
|
||||
MapIt it2 = m_plans.find( PlanKey(nfft,!inverse) );
|
||||
if (it2 != m_plans.end() ) {
|
||||
it->second = it2.second;
|
||||
it->second.invert();
|
||||
}else{
|
||||
it->second.make_twiddles(nfft,inverse);
|
||||
it->second.factorize(nfft);
|
||||
}
|
||||
}
|
||||
|
||||
k=u;
|
||||
for ( q1=0 ; q1<p ; ++q1 ) {
|
||||
int twidx=0;
|
||||
Fout[ k ] = scratchbuf[0];
|
||||
for (q=1;q<p;++q ) {
|
||||
twidx += fstride * k;
|
||||
if (twidx>=Norig) twidx-=Norig;
|
||||
t=scratchbuf[q] * twiddles[twidx];
|
||||
Fout[ k ] += t;
|
||||
}
|
||||
k += m;
|
||||
return it->second;
|
||||
*/
|
||||
PlanData & pd = m_plans[ PlanKey(nfft,inverse) ];
|
||||
if ( pd.m_twiddles.size() == 0 ) {
|
||||
pd.make_twiddles(nfft,inverse);
|
||||
pd.factorize(nfft);
|
||||
}
|
||||
}
|
||||
return pd;
|
||||
}
|
||||
|
||||
int m_nfft;
|
||||
bool m_inverse;
|
||||
std::vector<Complex> m_twiddles;
|
||||
std::vector<Complex> m_realTwiddles;
|
||||
std::vector<int> m_stageRadix;
|
||||
std::vector<int> m_stageRemainder;
|
||||
/*
|
||||
enum {FORWARD,INVERSE,REAL,COMPLEX};
|
||||
|
||||
struct PlanKey
|
||||
Complex * real_twiddles(int ncfft2)
|
||||
{
|
||||
PlanKey(int nfft,bool isinverse,bool iscomplex)
|
||||
{
|
||||
_key = (nfft<<2) | (isinverse<<1) | iscomplex;
|
||||
std::vector<Complex> & twidref = m_realTwiddles[ncfft2];// creates new if not there
|
||||
if ( (int)twidref.size() != ncfft2 ) {
|
||||
twidref.resize(ncfft2);
|
||||
int ncfft= ncfft2<<1;
|
||||
Scalar pi = acos( Scalar(-1) );
|
||||
for (int k=1;k<=ncfft2;++k)
|
||||
twidref[k-1] = exp( Complex(0,-pi * ((double) (k) / ncfft + .5) ) );
|
||||
}
|
||||
return &twidref[0];
|
||||
}
|
||||
|
||||
bool operator<(const PlanKey & other) const
|
||||
{
|
||||
return this->_key < other._key;
|
||||
}
|
||||
int _key;
|
||||
};
|
||||
|
||||
struct PlanData
|
||||
void scale(Complex *dst,int n,Scalar s)
|
||||
{
|
||||
std::vector<Complex> m_twiddles;
|
||||
};
|
||||
|
||||
std::map<PlanKey,
|
||||
*/
|
||||
for (int k=0;k<n;++k)
|
||||
dst[k] *= s;
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
@ -44,7 +44,7 @@ complex<long double> promote(long double x) { return complex<long double>( x);
|
||||
{
|
||||
long double totalpower=0;
|
||||
long double difpower=0;
|
||||
cerr <<"idx\ttruth\t\tvalue\n";
|
||||
cerr <<"idx\ttruth\t\tvalue\t|dif|=\n";
|
||||
for (size_t k0=0;k0<fftbuf.size();++k0) {
|
||||
complex<long double> acc = 0;
|
||||
long double phinc = -2.*k0* M_PIl / timebuf.size();
|
||||
@ -55,7 +55,7 @@ complex<long double> promote(long double x) { return complex<long double>( x);
|
||||
complex<long double> x = promote(fftbuf[k0]);
|
||||
complex<long double> dif = acc - x;
|
||||
difpower += norm(dif);
|
||||
cerr << k0 << "\t" << acc << "\t" << x << endl;
|
||||
cerr << k0 << "\t" << acc << "\t" << x << "\t" << sqrt(norm(dif)) << endl;
|
||||
}
|
||||
cerr << "rmse:" << sqrt(difpower/totalpower) << endl;
|
||||
return sqrt(difpower/totalpower);
|
||||
@ -127,8 +127,9 @@ void test_FFT()
|
||||
#endif
|
||||
|
||||
#if 1
|
||||
CALL_SUBTEST( test_scalar<float>(45) ); CALL_SUBTEST( test_scalar<double>(45) ); CALL_SUBTEST( test_scalar<long double>(45) );
|
||||
CALL_SUBTEST( test_scalar<float>(32) ); CALL_SUBTEST( test_scalar<double>(32) ); CALL_SUBTEST( test_scalar<long double>(32) );
|
||||
CALL_SUBTEST( test_scalar<float>(45) ); CALL_SUBTEST( test_scalar<double>(45) ); CALL_SUBTEST( test_scalar<long double>(45) );
|
||||
CALL_SUBTEST( test_scalar<float>(50) ); CALL_SUBTEST( test_scalar<double>(50) ); CALL_SUBTEST( test_scalar<long double>(50) );
|
||||
CALL_SUBTEST( test_scalar<float>(256) ); CALL_SUBTEST( test_scalar<double>(256) ); CALL_SUBTEST( test_scalar<long double>(256) );
|
||||
CALL_SUBTEST( test_scalar<float>(2*3*4*5*7) ); CALL_SUBTEST( test_scalar<double>(2*3*4*5*7) ); CALL_SUBTEST( test_scalar<long double>(2*3*4*5*7) );
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user