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found out about little-documented FFTW_PRESERVE_INPUT which has effect on c2r transforms

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This commit is contained in:
Mark Borgerding
2010-02-16 20:44:48 -05:00
parent 1d342e135c
commit 8f51a4ac90
5 changed files with 208 additions and 100 deletions
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151
unsupported/test/FFTW.cpp
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@@ -23,7 +23,7 @@
// Eigen. If not, see <http://www.gnu.org/licenses/>.
#include "main.h"
#include <fftw3.h>
#include <iostream>
#include <unsupported/Eigen/FFT>
template <typename T>
@@ -44,31 +44,30 @@ complex<long double> promote(double x) { return complex<long double>( x); }
complex<long double> promote(long double x) { return complex<long double>( x); }
template <typename T1,typename T2>
long double fft_rmse( const vector<T1> & fftbuf,const vector<T2> & timebuf)
template <typename VT1,typename VT2>
long double fft_rmse( const VT1 & fftbuf,const VT2 & timebuf)
{
long double totalpower=0;
long double difpower=0;
long double pi = acos((long double)-1 );
cerr <<"idx\ttruth\t\tvalue\t|dif|=\n";
for (size_t k0=0;k0<fftbuf.size();++k0) {
for (size_t k0=0;k0<(size_t)fftbuf.size();++k0) {
complex<long double> acc = 0;
long double phinc = -2.*k0* pi / timebuf.size();
for (size_t k1=0;k1<timebuf.size();++k1) {
for (size_t k1=0;k1<(size_t)timebuf.size();++k1) {
acc += promote( timebuf[k1] ) * exp( complex<long double>(0,k1*phinc) );
}
totalpower += norm(acc);
complex<long double> x = promote(fftbuf[k0]);
complex<long double> dif = acc - x;
difpower += norm(dif);
cerr << k0 << "\t" << acc << "\t" << x << "\t" << sqrt(norm(dif)) << endl;
//cerr << k0 << "\t" << acc << "\t" << x << "\t" << sqrt(norm(dif)) << endl;
}
cerr << "rmse:" << sqrt(difpower/totalpower) << endl;
return sqrt(difpower/totalpower);
}
template <typename T1,typename T2>
long double dif_rmse( const vector<T1> buf1,const vector<T2> buf2)
template <typename VT1,typename VT2>
long double dif_rmse( const VT1 buf1,const VT2 buf2)
{
long double totalpower=0;
long double difpower=0;
@@ -80,46 +79,132 @@ complex<long double> promote(long double x) { return complex<long double>( x);
return sqrt(difpower/totalpower);
}
template <class T>
void test_scalar(int nfft)
enum { StdVectorContainer, EigenVectorContainer };
template<int Container, typename Scalar> struct VectorType;
template<typename Scalar> struct VectorType<StdVectorContainer,Scalar>
{
typedef typename Eigen::FFT<T>::Complex Complex;
typedef typename Eigen::FFT<T>::Scalar Scalar;
typedef vector<Scalar> type;
};
template<typename Scalar> struct VectorType<EigenVectorContainer,Scalar>
{
typedef Matrix<Scalar,Dynamic,1> type;
};
template <int Container, typename T>
void test_scalar_generic(int nfft)
{
typedef typename FFT<T>::Complex Complex;
typedef typename FFT<T>::Scalar Scalar;
typedef typename VectorType<Container,Scalar>::type ScalarVector;
typedef typename VectorType<Container,Complex>::type ComplexVector;
FFT<T> fft;
vector<Scalar> inbuf(nfft);
vector<Complex> outbuf;
ScalarVector tbuf(nfft);
ComplexVector freqBuf;
for (int k=0;k<nfft;++k)
inbuf[k]= (T)(rand()/(double)RAND_MAX - .5);
fft.fwd( outbuf,inbuf);
VERIFY( fft_rmse(outbuf,inbuf) < test_precision<T>() );// gross check
tbuf[k]= (T)( rand()/(double)RAND_MAX - .5);
vector<Scalar> buf3;
fft.inv( buf3 , outbuf);
VERIFY( dif_rmse(inbuf,buf3) < test_precision<T>() );// gross check
cout << "tbuf=["; for (size_t i=0;i<(size_t) tbuf.size();++i) {cout << tbuf[i] << " ";} cout << "];\n";
// make sure it DOESN'T give the right full spectrum answer
// if we've asked for half-spectrum
fft.SetFlag(fft.HalfSpectrum );
fft.fwd( freqBuf,tbuf);
VERIFY((size_t)freqBuf.size() == (size_t)( (nfft>>1)+1) );
VERIFY( fft_rmse(freqBuf,tbuf) < test_precision<T>() );// gross check
fft.ClearFlag(fft.HalfSpectrum );
fft.fwd( freqBuf,tbuf);
VERIFY( (size_t)freqBuf.size() == (size_t)nfft);
VERIFY( fft_rmse(freqBuf,tbuf) < test_precision<T>() );// gross check
if (nfft&1)
return; // odd FFTs get the wrong size inverse FFT
ScalarVector tbuf2;
cout << "freqBuf=["; for (size_t i=0;i<(size_t) freqBuf.size();++i) {cout << freqBuf[i] << " ";} cout << "];\n";
fft.inv( tbuf2 , freqBuf);
cout << "tbuf2=["; for (size_t i=0;i<(size_t) tbuf2.size();++i) {cout << tbuf2[i] << " ";} cout << "];\n";
VERIFY( dif_rmse(tbuf,tbuf2) < test_precision<T>() );// gross check
// verify that the Unscaled flag takes effect
ScalarVector tbuf3;
fft.SetFlag(fft.Unscaled);
cout << "freqBuf=["; for (size_t i=0;i<(size_t) freqBuf.size();++i) {cout << freqBuf[i] << " ";} cout << "];\n";
fft.inv( tbuf3 , freqBuf);
cout << "tbuf3=["; for (size_t i=0;i<(size_t) tbuf3.size();++i) {cout << tbuf3[i] << " ";} cout << "];\n";
for (int k=0;k<nfft;++k)
tbuf3[k] *= T(1./nfft);
//for (size_t i=0;i<(size_t) tbuf.size();++i)
// cout << "freqBuf=" << freqBuf[i] << " in2=" << tbuf3[i] << " - in=" << tbuf[i] << " => " << (tbuf3[i] - tbuf[i] ) << endl;
cout << "dif_rmse = " << dif_rmse(tbuf,tbuf3) << endl;
cout << "test_precision = " << test_precision<T>() << endl;
VERIFY( dif_rmse(tbuf,tbuf3) < test_precision<T>() );// gross check
// verify that ClearFlag works
fft.ClearFlag(fft.Unscaled);
fft.inv( tbuf2 , freqBuf);
VERIFY( dif_rmse(tbuf,tbuf2) < test_precision<T>() );// gross check
}
template <class T>
void test_complex(int nfft)
template <typename T>
void test_scalar(int nfft)
{
typedef typename Eigen::FFT<T>::Complex Complex;
test_scalar_generic<StdVectorContainer,T>(nfft);
//test_scalar_generic<EigenVectorContainer,T>(nfft);
}
template <int Container, typename T>
void test_complex_generic(int nfft)
{
typedef typename FFT<T>::Complex Complex;
typedef typename VectorType<Container,Complex>::type ComplexVector;
FFT<T> fft;
vector<Complex> inbuf(nfft);
vector<Complex> outbuf;
vector<Complex> buf3;
ComplexVector inbuf(nfft);
ComplexVector outbuf;
ComplexVector buf3;
for (int k=0;k<nfft;++k)
inbuf[k]= RandomCpx<T>();
inbuf[k]= Complex( (T)(rand()/(double)RAND_MAX - .5), (T)(rand()/(double)RAND_MAX - .5) );
fft.fwd( outbuf , inbuf);
VERIFY( fft_rmse(outbuf,inbuf) < test_precision<T>() );// gross check
fft.inv( buf3 , outbuf);
VERIFY( dif_rmse(inbuf,buf3) < test_precision<T>() );// gross check
// verify that the Unscaled flag takes effect
ComplexVector buf4;
fft.SetFlag(fft.Unscaled);
fft.inv( buf4 , outbuf);
for (int k=0;k<nfft;++k)
buf4[k] *= T(1./nfft);
VERIFY( dif_rmse(inbuf,buf4) < test_precision<T>() );// gross check
// verify that ClearFlag works
fft.ClearFlag(fft.Unscaled);
fft.inv( buf3 , outbuf);
VERIFY( dif_rmse(inbuf,buf3) < test_precision<T>() );// gross check
}
template <typename T>
void test_complex(int nfft)
{
test_complex_generic<StdVectorContainer,T>(nfft);
test_complex_generic<EigenVectorContainer,T>(nfft);
}
/*
template <typename T,int nrows,int ncols>
void test_complex2d()
{
@@ -142,16 +227,16 @@ void test_complex2d()
dst2.row(k) = tmpOut;
}
fft.fwd2(dst.data(),src.data(),nrows,ncols);
fft.inv2(src2.data(),dst.data(),nrows,ncols);
fft.fwd2(dst.data(),src.data(),ncols,nrows);
fft.inv2(src2.data(),dst.data(),ncols,nrows);
VERIFY( (src-src2).norm() < test_precision<T>() );
VERIFY( (dst-dst2).norm() < test_precision<T>() );
}
*/
void test_FFTW()
{
CALL_SUBTEST( ( test_complex2d<float,4,8> () ) );
CALL_SUBTEST( ( test_complex2d<double,4,8> () ) );
//CALL_SUBTEST( ( test_complex2d<float,4,8> () ) ); CALL_SUBTEST( ( test_complex2d<double,4,8> () ) );
//CALL_SUBTEST( ( test_complex2d<long double,4,8> () ) );
CALL_SUBTEST( test_complex<float>(32) ); CALL_SUBTEST( test_complex<double>(32) ); CALL_SUBTEST( test_complex<long double>(32) );
CALL_SUBTEST( test_complex<float>(256) ); CALL_SUBTEST( test_complex<double>(256) ); CALL_SUBTEST( test_complex<long double>(256) );