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Diffstat (limited to 'unsupported/Eigen/src/FFT/ei_fftw_impl.h')
| -rw-r--r-- | unsupported/Eigen/src/FFT/ei_fftw_impl.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/unsupported/Eigen/src/FFT/ei_fftw_impl.h b/unsupported/Eigen/src/FFT/ei_fftw_impl.h new file mode 100644 index 000000000..d592bbb20 --- /dev/null +++ b/unsupported/Eigen/src/FFT/ei_fftw_impl.h @@ -0,0 +1,198 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2009 Mark Borgerding mark a borgerding net +// +// Eigen is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 3 of the License, or (at your option) any later version. +// +// Alternatively, you can redistribute it and/or +// modify it under the terms of the GNU General Public License as +// published by the Free Software Foundation; either version 2 of +// the License, or (at your option) any later version. +// +// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public +// License and a copy of the GNU General Public License along with +// Eigen. If not, see <http://www.gnu.org/licenses/>. + +namespace Eigen { + // FFTW uses non-const arguments + // so we must use ugly const_cast calls for all the args it uses + // + // This should be safe as long as + // 1. we use FFTW_ESTIMATE for all our planning + // see the FFTW docs section 4.3.2 "Planner Flags" + // 2. fftw_complex is compatible with std::complex + // This assumes std::complex<T> layout is array of size 2 with real,imag + template <typename T> + T * ei_fftw_cast(const T* p) + { + return const_cast<T*>( p); + } + + fftw_complex * ei_fftw_cast( const std::complex<double> * p) + { + return const_cast<fftw_complex*>( reinterpret_cast<const fftw_complex*>(p) ); + } + + fftwf_complex * ei_fftw_cast( const std::complex<float> * p) + { + return const_cast<fftwf_complex*>( reinterpret_cast<const fftwf_complex*>(p) ); + } + + fftwl_complex * ei_fftw_cast( const std::complex<long double> * p) + { + return const_cast<fftwl_complex*>( reinterpret_cast<const fftwl_complex*>(p) ); + } + + template <typename T> + struct ei_fftw_plan {}; + + template <> + struct ei_fftw_plan<float> + { + typedef float scalar_type; + typedef fftwf_complex complex_type; + fftwf_plan m_plan; + ei_fftw_plan() :m_plan(NULL) {} + ~ei_fftw_plan() {if (m_plan) fftwf_destroy_plan(m_plan);} + + void fwd(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwf_plan_dft_1d(nfft,src,dst, FFTW_FORWARD, FFTW_ESTIMATE); + fftwf_execute_dft( m_plan, src,dst); + } + void inv(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwf_plan_dft_1d(nfft,src,dst, FFTW_BACKWARD , FFTW_ESTIMATE); + fftwf_execute_dft( m_plan, src,dst); + } + void fwd(complex_type * dst,scalar_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwf_plan_dft_r2c_1d(nfft,src,dst,FFTW_ESTIMATE); + fftwf_execute_dft_r2c( m_plan,src,dst); + } + void inv(scalar_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) + m_plan = fftwf_plan_dft_c2r_1d(nfft,src,dst,FFTW_ESTIMATE); + fftwf_execute_dft_c2r( m_plan, src,dst); + } + }; + template <> + struct ei_fftw_plan<double> + { + typedef double scalar_type; + typedef fftw_complex complex_type; + fftw_plan m_plan; + ei_fftw_plan() :m_plan(NULL) {} + ~ei_fftw_plan() {if (m_plan) fftw_destroy_plan(m_plan);} + + void fwd(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftw_plan_dft_1d(nfft,src,dst, FFTW_FORWARD, FFTW_ESTIMATE); + fftw_execute_dft( m_plan, src,dst); + } + void inv(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftw_plan_dft_1d(nfft,src,dst, FFTW_BACKWARD , FFTW_ESTIMATE); + fftw_execute_dft( m_plan, src,dst); + } + void fwd(complex_type * dst,scalar_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftw_plan_dft_r2c_1d(nfft,src,dst,FFTW_ESTIMATE); + fftw_execute_dft_r2c( m_plan,src,dst); + } + void inv(scalar_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) + m_plan = fftw_plan_dft_c2r_1d(nfft,src,dst,FFTW_ESTIMATE); + fftw_execute_dft_c2r( m_plan, src,dst); + } + }; + template <> + struct ei_fftw_plan<long double> + { + typedef long double scalar_type; + typedef fftwl_complex complex_type; + fftwl_plan m_plan; + ei_fftw_plan() :m_plan(NULL) {} + ~ei_fftw_plan() {if (m_plan) fftwl_destroy_plan(m_plan);} + + void fwd(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwl_plan_dft_1d(nfft,src,dst, FFTW_FORWARD, FFTW_ESTIMATE); + fftwl_execute_dft( m_plan, src,dst); + } + void inv(complex_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwl_plan_dft_1d(nfft,src,dst, FFTW_BACKWARD , FFTW_ESTIMATE); + fftwl_execute_dft( m_plan, src,dst); + } + void fwd(complex_type * dst,scalar_type * src,int nfft) { + if (m_plan==NULL) m_plan = fftwl_plan_dft_r2c_1d(nfft,src,dst,FFTW_ESTIMATE); + fftwl_execute_dft_r2c( m_plan,src,dst); + } + void inv(scalar_type * dst,complex_type * src,int nfft) { + if (m_plan==NULL) + m_plan = fftwl_plan_dft_c2r_1d(nfft,src,dst,FFTW_ESTIMATE); + fftwl_execute_dft_c2r( m_plan, src,dst); + } + }; + + template <typename _Scalar> + struct ei_fftw_impl + { + typedef _Scalar Scalar; + typedef std::complex<Scalar> Complex; + + void clear() + { + m_plans.clear(); + } + + void fwd( Complex * dst,const Complex *src,int nfft) + { + get_plan(nfft,false,dst,src).fwd(ei_fftw_cast(dst), ei_fftw_cast(src),nfft ); + } + + // real-to-complex forward FFT + void fwd( Complex * dst,const Scalar * src,int nfft) + { + get_plan(nfft,false,dst,src).fwd(ei_fftw_cast(dst), ei_fftw_cast(src) ,nfft); + int nhbins=(nfft>>1)+1; + for (int k=nhbins;k < nfft; ++k ) + dst[k] = conj(dst[nfft-k]); + } + + // inverse complex-to-complex + void inv(Complex * dst,const Complex *src,int nfft) + { + get_plan(nfft,true,dst,src).inv(ei_fftw_cast(dst), ei_fftw_cast(src),nfft ); + // scaling + Scalar s = 1./nfft; + for (int k=0;k<nfft;++k) + dst[k] *= s; + } + + // half-complex to scalar + void inv( Scalar * dst,const Complex * src,int nfft) + { + get_plan(nfft,true,dst,src).inv(ei_fftw_cast(dst), ei_fftw_cast(src),nfft ); + Scalar s = 1./nfft; + for (int k=0;k<nfft;++k) + dst[k] *= s; + } + + private: + typedef ei_fftw_plan<Scalar> PlanData; + typedef std::map<int,PlanData> PlanMap; + + PlanMap m_plans; + + PlanData & get_plan(int nfft,bool inverse,void * dst,const void * src) + { + bool inplace = (dst==src); + bool aligned = ( (reinterpret_cast<size_t>(src)&15) | (reinterpret_cast<size_t>(dst)&15) ) == 0; + int key = (nfft<<3 ) | (inverse<<2) | (inplace<<1) | aligned; + return m_plans[key]; + } + }; +} |