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Merge pull request #12 from steffen-kiess/cpp-fix-precision

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Use std::acos() instead of acos() in C++ version
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mborgerding 2018-11-26 12:45:36 -05:00 committed by GitHub
commit 07e6dd04aa
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1 changed files with 6 additions and 6 deletions
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12
kissfft.hh
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@ -27,9 +27,9 @@ class kissfft
{
// fill twiddle factors
_twiddles.resize(_nfft);
const scalar_t phinc = (_inverse?2:-2)* acos( (scalar_t) -1) / _nfft;
const scalar_t phinc = (_inverse?2:-2)* std::acos( (scalar_t) -1) / _nfft;
for (std::size_t i=0;i<_nfft;++i)
_twiddles[i] = exp( cpx_t(0,i*phinc) );
_twiddles[i] = std::exp( cpx_t(0,i*phinc) );
//factorize
//start factoring out 4's, then 2's, then 3,5,7,9,...
@ -166,9 +166,9 @@ class kissfft
dst[0].real() - dst[0].imag() );
// post processing for all the other k = 1, 2, ..., N-1
const scalar_t pi = acos( (scalar_t) -1);
const scalar_t pi = std::acos( (scalar_t) -1);
const scalar_t half_phi_inc = ( _inverse ? pi : -pi ) / N;
const cpx_t twiddle_mul = exp( cpx_t(0, half_phi_inc) );
const cpx_t twiddle_mul = std::exp( cpx_t(0, half_phi_inc) );
for ( std::size_t k = 1; 2*k < N; ++k )
{
const cpx_t w = (scalar_t)0.5 * cpx_t(
@ -182,10 +182,10 @@ class kissfft
_twiddles[k/2] :
_twiddles[k/2] * twiddle_mul;
dst[ k] = w + twiddle * z;
dst[N-k] = conj( w - twiddle * z );
dst[N-k] = std::conj( w - twiddle * z );
}
if ( N % 2 == 0 )
dst[N/2] = conj( dst[N/2] );
dst[N/2] = std::conj( dst[N/2] );
}
private: