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authorGravatar Mark Borgerding <mark@borgerding.net>2009-10-31 00:13:22 -0400
committerGravatar Mark Borgerding <mark@borgerding.net>2009-10-31 00:13:22 -0400
commitec70f8006be1e46055a0d65850c8c60c3bebf6ed (patch)
tree32621c8a9a67827165cd02e3caefa45347c8f411 /unsupported
parent4c3345364e079429dcfc17da63364ee75b9c0636 (diff)
added inlines to a bunch of functions
Diffstat (limited to 'unsupported')
-rw-r--r--unsupported/Eigen/FFT12
-rw-r--r--unsupported/Eigen/src/FFT/ei_fftw_impl.h3
-rw-r--r--unsupported/Eigen/src/FFT/ei_kissfft_impl.h695
3 files changed, 365 insertions, 345 deletions
diff --git a/unsupported/Eigen/FFT b/unsupported/Eigen/FFT
index b1d3d9f0e..8f7a2fcae 100644
--- a/unsupported/Eigen/FFT
+++ b/unsupported/Eigen/FFT
@@ -85,6 +85,7 @@ class FFT
inline
void ClearFlag(Flag f) { m_flag &= (~(int)f);}
+ inline
void fwd( Complex * dst, const Scalar * src, int nfft)
{
m_impl.fwd(dst,src,nfft);
@@ -92,12 +93,14 @@ class FFT
ReflectSpectrum(dst,nfft);
}
+ inline
void fwd( Complex * dst, const Complex * src, int nfft)
{
m_impl.fwd(dst,src,nfft);
}
template <typename _Input>
+ inline
void fwd( std::vector<Complex> & dst, const std::vector<_Input> & src)
{
if ( NumTraits<_Input>::IsComplex == 0 && HasFlag(HalfSpectrum) )
@@ -108,6 +111,7 @@ class FFT
}
template<typename InputDerived, typename ComplexDerived>
+ inline
void fwd( MatrixBase<ComplexDerived> & dst, const MatrixBase<InputDerived> & src)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(InputDerived)
@@ -125,6 +129,7 @@ class FFT
fwd( &dst[0],&src[0],src.size() );
}
+ inline
void inv( Complex * dst, const Complex * src, int nfft)
{
m_impl.inv( dst,src,nfft );
@@ -132,6 +137,7 @@ class FFT
scale(dst,1./nfft,nfft);
}
+ inline
void inv( Scalar * dst, const Complex * src, int nfft)
{
m_impl.inv( dst,src,nfft );
@@ -140,6 +146,7 @@ class FFT
}
template<typename OutputDerived, typename ComplexDerived>
+ inline
void inv( MatrixBase<OutputDerived> & dst, const MatrixBase<ComplexDerived> & src)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(OutputDerived)
@@ -157,6 +164,7 @@ class FFT
}
template <typename _Output>
+ inline
void inv( std::vector<_Output> & dst, const std::vector<Complex> & src)
{
if ( NumTraits<_Output>::IsComplex == 0 && HasFlag(HalfSpectrum) )
@@ -171,18 +179,22 @@ class FFT
// TODO: handle Eigen MatrixBase
// ---> i added fwd and inv specializations above + unit test, is this enough? (bjacob)
+ inline
impl_type & impl() {return m_impl;}
private:
template <typename _It,typename _Val>
+ inline
void scale(_It x,_Val s,int nx)
{
for (int k=0;k<nx;++k)
*x++ *= s;
}
+ inline
void ReflectSpectrum(Complex * freq,int nfft)
{
+ // create the implicit right-half spectrum (conjugate-mirror of the left-half)
int nhbins=(nfft>>1)+1;
for (int k=nhbins;k < nfft; ++k )
freq[k] = conj(freq[nfft-k]);
diff --git a/unsupported/Eigen/src/FFT/ei_fftw_impl.h b/unsupported/Eigen/src/FFT/ei_fftw_impl.h
index 18473a29b..a66b7398c 100644
--- a/unsupported/Eigen/src/FFT/ei_fftw_impl.h
+++ b/unsupported/Eigen/src/FFT/ei_fftw_impl.h
@@ -166,6 +166,7 @@
m_plans.clear();
}
+ // complex-to-complex forward FFT
inline
void fwd( Complex * dst,const Complex *src,int nfft)
{
@@ -208,3 +209,5 @@
return m_plans[key];
}
};
+/* vim: set filetype=cpp et sw=2 ts=2 ai: */
+
diff --git a/unsupported/Eigen/src/FFT/ei_kissfft_impl.h b/unsupported/Eigen/src/FFT/ei_kissfft_impl.h
index 091e730d1..5c958d1ec 100644
--- a/unsupported/Eigen/src/FFT/ei_kissfft_impl.h
+++ b/unsupported/Eigen/src/FFT/ei_kissfft_impl.h
@@ -27,379 +27,384 @@
// This FFT implementation was derived from kissfft http:sourceforge.net/projects/kissfft
// Copyright 2003-2009 Mark Borgerding
- template <typename _Scalar>
- struct ei_kiss_cpx_fft
+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;
+ std::vector<Complex> m_scratchBuf;
+ bool m_inverse;
+
+ inline
+ void make_twiddles(int nfft,bool inverse)
{
- typedef _Scalar Scalar;
- typedef std::complex<Scalar> Complex;
- std::vector<Complex> m_twiddles;
- std::vector<int> m_stageRadix;
- std::vector<int> m_stageRemainder;
- std::vector<Complex> m_scratchBuf;
- bool m_inverse;
-
- 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) );
+ 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 factorize(int nfft)
+ {
+ //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);
+ if ( p > 5 )
+ m_scratchBuf.resize(p); // scratchbuf will be needed in bfly_generic
+ }while(n>1);
+ }
+
+ template <typename _Src>
+ inline
+ 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;
- void factorize(int nfft)
- {
- //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);
- if ( p > 5 )
- m_scratchBuf.resize(p); // scratchbuf will be needed in bfly_generic
- }while(n>1);
+ 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 );
}
-
- 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;
- }
- }
-
- inline
- 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;
- }
+ 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;
}
+ }
- inline
- 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];
- }
+ inline
+ 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;
}
+ }
- inline
- 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);
+ inline
+ 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];
}
+ }
- inline
- 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())
+ inline
+ 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);
+ }
+
+ inline
+ 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())
);
- *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())
- );
+ 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];
+ *Fout2=scratch[11]+scratch[12];
+ *Fout3=scratch[11]-scratch[12];
- ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
- }
+ ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
}
+ }
+
+ /* perform the butterfly for one stage of a mixed radix FFT */
+ inline
+ 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 = &m_scratchBuf[0];
+
+ for ( u=0; u<m; ++u ) {
+ k=u;
+ for ( q1=0 ; q1<p ; ++q1 ) {
+ scratchbuf[q1] = Fout[ k ];
+ k += m;
+ }
- /* perform the butterfly for one stage of a mixed radix FFT */
- inline
- 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 = &m_scratchBuf[0];
-
- 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;
+ 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
+ }
+};
+
+template <typename _Scalar>
+struct ei_kissfft_impl
+{
+ typedef _Scalar Scalar;
+ typedef std::complex<Scalar> Complex;
+
+ void clear()
+ {
+ m_plans.clear();
+ m_realTwiddles.clear();
+ }
+
+ inline
+ void fwd( Complex * dst,const Complex *src,int nfft)
{
- typedef _Scalar Scalar;
- typedef std::complex<Scalar> Complex;
-
- void clear()
- {
- m_plans.clear();
- m_realTwiddles.clear();
+ get_plan(nfft,false).work(0, dst, src, 1,1);
+ }
+
+ // real-to-complex forward FFT
+ // perform two FFTs of src even and src odd
+ // then twiddle to recombine them into the half-spectrum format
+ // then fill in the conjugate symmetric half
+ inline
+ void fwd( Complex * dst,const Scalar * src,int nfft)
+ {
+ if ( nfft&3 ) {
+ // use generic mode for odd
+ m_tmpBuf1.resize(nfft);
+ get_plan(nfft,false).work(0, &m_tmpBuf1[0], src, 1,1);
+ std::copy(m_tmpBuf1.begin(),m_tmpBuf1.begin()+(nfft>>1)+1,dst );
+ }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);
+ Complex dc = dst[0].real() + dst[0].imag();
+ Complex nyquist = dst[0].real() - dst[0].imag();
+ int k;
+ for ( k=1;k <= ncfft2 ; ++k ) {
+ Complex fpk = dst[k];
+ Complex fpnk = conj(dst[ncfft-k]);
+ Complex f1k = fpk + fpnk;
+ Complex f2k = fpk - fpnk;
+ Complex tw= f2k * rtw[k-1];
+ dst[k] = (f1k + tw) * Scalar(.5);
+ dst[ncfft-k] = conj(f1k -tw)*Scalar(.5);
+ }
+ dst[0] = dc;
+ dst[ncfft] = nyquist;
}
+ }
- inline
- void fwd( Complex * dst,const Complex *src,int nfft)
- {
- get_plan(nfft,false).work(0, dst, src, 1,1);
- }
+ // inverse complex-to-complex
+ inline
+ void inv(Complex * dst,const Complex *src,int nfft)
+ {
+ get_plan(nfft,true).work(0, dst, src, 1,1);
+ }
- // real-to-complex forward FFT
- // perform two FFTs of src even and src odd
- // then twiddle to recombine them into the half-spectrum format
- // then fill in the conjugate symmetric half
- inline
- void fwd( Complex * dst,const Scalar * src,int nfft)
- {
- if ( nfft&3 ) {
- // use generic mode for odd
- m_tmpBuf1.resize(nfft);
- get_plan(nfft,false).work(0, &m_tmpBuf1[0], src, 1,1);
- std::copy(m_tmpBuf1.begin(),m_tmpBuf1.begin()+(nfft>>1)+1,dst );
- }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);
- Complex dc = dst[0].real() + dst[0].imag();
- Complex nyquist = dst[0].real() - dst[0].imag();
- int k;
- for ( k=1;k <= ncfft2 ; ++k ) {
- Complex fpk = dst[k];
- Complex fpnk = conj(dst[ncfft-k]);
- Complex f1k = fpk + fpnk;
- Complex f2k = fpk - fpnk;
- Complex tw= f2k * rtw[k-1];
- dst[k] = (f1k + tw) * Scalar(.5);
- dst[ncfft-k] = conj(f1k -tw)*Scalar(.5);
- }
- dst[0] = dc;
- dst[ncfft] = nyquist;
+ // half-complex to scalar
+ inline
+ void inv( Scalar * dst,const Complex * src,int nfft)
+ {
+ if (nfft&3) {
+ m_tmpBuf1.resize(nfft);
+ m_tmpBuf2.resize(nfft);
+ std::copy(src,src+(nfft>>1)+1,m_tmpBuf1.begin() );
+ for (int k=1;k<(nfft>>1)+1;++k)
+ m_tmpBuf1[nfft-k] = conj(m_tmpBuf1[k]);
+ inv(&m_tmpBuf2[0],&m_tmpBuf1[0],nfft);
+ for (int k=0;k<nfft;++k)
+ dst[k] = m_tmpBuf2[k].real();
+ }else{
+ // optimized version for multiple of 4
+ int ncfft = nfft>>1;
+ int ncfft2 = nfft>>2;
+ Complex * rtw = real_twiddles(ncfft2);
+ m_tmpBuf1.resize(ncfft);
+ m_tmpBuf1[0] = Complex( src[0].real() + src[ncfft].real(), src[0].real() - src[ncfft].real() );
+ for (int k = 1; k <= ncfft / 2; ++k) {
+ Complex fk = src[k];
+ Complex fnkc = conj(src[ncfft-k]);
+ Complex fek = fk + fnkc;
+ Complex tmp = fk - fnkc;
+ Complex fok = tmp * conj(rtw[k-1]);
+ m_tmpBuf1[k] = fek + fok;
+ m_tmpBuf1[ncfft-k] = conj(fek - fok);
}
+ get_plan(ncfft,true).work(0, reinterpret_cast<Complex*>(dst), &m_tmpBuf1[0], 1,1);
}
+ }
- // inverse complex-to-complex
- inline
- void inv(Complex * dst,const Complex *src,int nfft)
- {
- get_plan(nfft,true).work(0, dst, src, 1,1);
- }
+ protected:
+ typedef ei_kiss_cpx_fft<Scalar> PlanData;
+ typedef std::map<int,PlanData> PlanMap;
- // half-complex to scalar
- inline
- void inv( Scalar * dst,const Complex * src,int nfft)
- {
- if (nfft&3) {
- m_tmpBuf1.resize(nfft);
- m_tmpBuf2.resize(nfft);
- std::copy(src,src+(nfft>>1)+1,m_tmpBuf1.begin() );
- for (int k=1;k<(nfft>>1)+1;++k)
- m_tmpBuf1[nfft-k] = conj(m_tmpBuf1[k]);
- inv(&m_tmpBuf2[0],&m_tmpBuf1[0],nfft);
- for (int k=0;k<nfft;++k)
- dst[k] = m_tmpBuf2[k].real();
- }else{
- // optimized version for multiple of 4
- int ncfft = nfft>>1;
- int ncfft2 = nfft>>2;
- Complex * rtw = real_twiddles(ncfft2);
- m_tmpBuf1.resize(ncfft);
- m_tmpBuf1[0] = Complex( src[0].real() + src[ncfft].real(), src[0].real() - src[ncfft].real() );
- for (int k = 1; k <= ncfft / 2; ++k) {
- Complex fk = src[k];
- Complex fnkc = conj(src[ncfft-k]);
- Complex fek = fk + fnkc;
- Complex tmp = fk - fnkc;
- Complex fok = tmp * conj(rtw[k-1]);
- m_tmpBuf1[k] = fek + fok;
- m_tmpBuf1[ncfft-k] = conj(fek - fok);
- }
- get_plan(ncfft,true).work(0, reinterpret_cast<Complex*>(dst), &m_tmpBuf1[0], 1,1);
- }
- }
+ PlanMap m_plans;
+ std::map<int, std::vector<Complex> > m_realTwiddles;
+ std::vector<Complex> m_tmpBuf1;
+ std::vector<Complex> m_tmpBuf2;
- protected:
- typedef ei_kiss_cpx_fft<Scalar> PlanData;
- typedef std::map<int,PlanData> PlanMap;
-
- PlanMap m_plans;
- std::map<int, std::vector<Complex> > m_realTwiddles;
- std::vector<Complex> m_tmpBuf1;
- std::vector<Complex> m_tmpBuf2;
-
- inline
- int PlanKey(int nfft,bool isinverse) const { return (nfft<<1) | isinverse; }
-
- inline
- PlanData & get_plan(int nfft,bool inverse)
- {
- // TODO look for PlanKey(nfft, ! inverse) and conjugate the twiddles
- PlanData & pd = m_plans[ PlanKey(nfft,inverse) ];
- if ( pd.m_twiddles.size() == 0 ) {
- pd.make_twiddles(nfft,inverse);
- pd.factorize(nfft);
- }
- return pd;
+ inline
+ int PlanKey(int nfft,bool isinverse) const { return (nfft<<1) | isinverse; }
+
+ inline
+ PlanData & get_plan(int nfft,bool inverse)
+ {
+ // TODO look for PlanKey(nfft, ! inverse) and conjugate the twiddles
+ PlanData & pd = m_plans[ PlanKey(nfft,inverse) ];
+ if ( pd.m_twiddles.size() == 0 ) {
+ pd.make_twiddles(nfft,inverse);
+ pd.factorize(nfft);
}
+ return pd;
+ }
- inline
- Complex * real_twiddles(int ncfft2)
- {
- 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];
+ inline
+ Complex * real_twiddles(int ncfft2)
+ {
+ 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];
+ }
+};
+
+/* vim: set filetype=cpp et sw=2 ts=2 ai: */
+