FFT.cpp File Reference

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Functions
void	demo_all_types (int nfft)
template<typename T_time , typename T_freq >
void	fwd_inv (size_t nfft)
template<typename T >
T	mag2 (const std::vector< std::complex< T > > &vec)
template<typename T >
T	mag2 (const std::vector< T > &vec)
template<typename T >
T	mag2 (std::complex< T > a)
template<typename T >
T	mag2 (T a)
int	main ()
template<typename T >
vector< T >	operator- (const vector< T > &a, const vector< T > &b)
template<typename T >
void	RandomFill (std::vector< std::complex< T > > &vec)
template<typename T >
void	RandomFill (std::vector< T > &vec)
template<typename T_scalar >
void	two_demos (int nfft)

Function Documentation

demo_all_types()

void demo_all_types

(

int

nfft

)

Definition at line 101 of file FFT.cpp.

{
    cout << "nfft=" << nfft << endl;
    cout << "   float" << endl;
    two_demos<float>(nfft);
    cout << "   double" << endl;
    two_demos<double>(nfft);
    cout << "   long double" << endl;
    two_demos<long double>(nfft);
}

fwd_inv()

template<typename T_time , typename T_freq >

void fwd_inv

(

size_t

nfft

)

Definition at line 75 of file FFT.cpp.

{
    typedef typename NumTraits<T_freq>::Real Scalar;
    vector<T_time> timebuf(nfft);
    RandomFill(timebuf);
 
    vector<T_freq> freqbuf;
    static FFT<Scalar> fft;
    fft.fwd(freqbuf,timebuf);
 
    vector<T_time> timebuf2;
    fft.inv(timebuf2,freqbuf);
 
    T_time rmse = mag2(timebuf - timebuf2) / mag2(timebuf);
    cout << "roundtrip rmse: " << rmse << endl;
}

mag2() [1/4]

template<typename T >

T mag2

(

const std::vector< std::complex< T > > &

vec

)

Definition at line 43 of file FFT.cpp.

{
    T out=0;
    for (size_t k=0;k<vec.size();++k)
        out += mag2(vec[k]);
    return out;
}

mag2() [2/4]

template<typename T >

T mag2

(

const std::vector< T > &

vec

)

Definition at line 34 of file FFT.cpp.

{
    T out=0;
    for (size_t k=0;k<vec.size();++k)
        out += mag2(vec[k]);
    return out;
}

mag2() [3/4]

template<typename T >

T mag2

(

std::complex< T >

a

)

Definition at line 28 of file FFT.cpp.

{
    return norm(a);
}

mag2() [4/4]

template<typename T >

T mag2

(

T

a

)

Definition at line 23 of file FFT.cpp.

{
    return a*a;
}

main()

int main

(

)

Definition at line 112 of file FFT.cpp.

{
    demo_all_types( 2*3*4*5*7 );
    demo_all_types( 2*9*16*25 );
    demo_all_types( 1024 );
    return 0;
}

operator-()

template<typename T >

vector<T> operator-	(	const vector< T > &	a,
		const vector< T > &	b
	)

Definition at line 52 of file FFT.cpp.

{
    vector<T> c(a);
    for (size_t k=0;k<b.size();++k) 
        c[k] -= b[k];
    return c;
}

RandomFill() [1/2]

template<typename T >

void RandomFill

(

std::vector< std::complex< T > > &

vec

)

Definition at line 68 of file FFT.cpp.

{
    for (size_t k=0;k<vec.size();++k)
        vec[k] = std::complex<T> ( T( rand() )/T(RAND_MAX) - T(.5), T( rand() )/T(RAND_MAX) - T(.5));
}

RandomFill() [2/2]

template<typename T >

void RandomFill

(

std::vector< T > &

vec

)

Definition at line 61 of file FFT.cpp.

{
    for (size_t k=0;k<vec.size();++k)
        vec[k] = T( rand() )/T(RAND_MAX) - T(.5);
}

two_demos()

template<typename T_scalar >

void two_demos

(

int

nfft

)

Definition at line 93 of file FFT.cpp.

{
    cout << "     scalar ";
    fwd_inv<T_scalar,std::complex<T_scalar> >(nfft);
    cout << "    complex ";
    fwd_inv<std::complex<T_scalar>,std::complex<T_scalar> >(nfft);
}