moved real-half-spectrum reflection into Eigen::FFT

This commit is contained in:
Mark Borgerding 2009-10-30 20:26:30 -04:00
parent a26b729cc9
commit d659fd9b14
3 changed files with 22 additions and 15 deletions

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@ -88,6 +88,8 @@ class FFT
void fwd( Complex * dst, const Scalar * src, int nfft)
{
m_impl.fwd(dst,src,nfft);
if ( HasFlag(HalfSpectrum) == false)
ReflectSpectrum(dst,nfft);
}
void fwd( Complex * dst, const Complex * src, int nfft)
@ -108,15 +110,19 @@ class FFT
template<typename InputDerived, typename ComplexDerived>
void fwd( MatrixBase<ComplexDerived> & dst, const MatrixBase<InputDerived> & src)
{
EIGEN_STATIC_ASSERT_VECTOR_ONLY(InputDerived)
EIGEN_STATIC_ASSERT_VECTOR_ONLY(ComplexDerived)
EIGEN_STATIC_ASSERT_SAME_VECTOR_SIZE(ComplexDerived,InputDerived) // size at compile-time
EIGEN_STATIC_ASSERT((ei_is_same_type<typename ComplexDerived::Scalar, Complex>::ret),
YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
EIGEN_STATIC_ASSERT(int(InputDerived::Flags)&int(ComplexDerived::Flags)&DirectAccessBit,
THIS_METHOD_IS_ONLY_FOR_EXPRESSIONS_WITH_DIRECT_MEMORY_ACCESS_SUCH_AS_MAP_OR_PLAIN_MATRICES)
dst.derived().resize( src.size() );
fwd( &dst[0],&src[0],src.size() );
EIGEN_STATIC_ASSERT_VECTOR_ONLY(InputDerived)
EIGEN_STATIC_ASSERT_VECTOR_ONLY(ComplexDerived)
EIGEN_STATIC_ASSERT_SAME_VECTOR_SIZE(ComplexDerived,InputDerived) // size at compile-time
EIGEN_STATIC_ASSERT((ei_is_same_type<typename ComplexDerived::Scalar, Complex>::ret),
YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
EIGEN_STATIC_ASSERT(int(InputDerived::Flags)&int(ComplexDerived::Flags)&DirectAccessBit,
THIS_METHOD_IS_ONLY_FOR_EXPRESSIONS_WITH_DIRECT_MEMORY_ACCESS_SUCH_AS_MAP_OR_PLAIN_MATRICES)
if ( NumTraits< typename InputDerived::Scalar >::IsComplex == 0 && HasFlag(HalfSpectrum) )
dst.derived().resize( (src.size()>>1)+1);
else
dst.derived().resize(src.size());
fwd( &dst[0],&src[0],src.size() );
}
void inv( Complex * dst, const Complex * src, int nfft)
@ -160,7 +166,6 @@ class FFT
inv( &dst[0],&src[0],dst.size() );
}
// TODO: multi-dimensional FFTs
// TODO: handle Eigen MatrixBase
@ -176,6 +181,13 @@ class FFT
*x++ *= s;
}
void ReflectSpectrum(Complex * freq,int nfft)
{
int nhbins=(nfft>>1)+1;
for (int k=nhbins;k < nfft; ++k )
freq[k] = conj(freq[nfft-k]);
}
impl_type m_impl;
int m_flag;
};

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@ -177,9 +177,6 @@
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

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@ -322,8 +322,6 @@
// place conjugate-symmetric half at the end for completeness
// TODO: make this configurable ( opt-out )
for ( k=1;k < ncfft ; ++k )
dst[nfft-k] = conj(dst[k]);
dst[0] = dc;
dst[ncfft] = nyquist;
}