latest version v1.9 - last update 24 Nov 2005

lti::fft Namespace Reference

Namespace with all FFT and inverse FFT routines based on code by Takuya Ooura with kind permission ooura@kurims.kyoto-u.ac.jp or ooura@mmm.t.u-tokyo.ac.jp). More...

Functions
template<class T>
T *	alloc_1d (const int &n1)
template<class T>
void	free_1d (T *i)
template<class T>
T **	alloc_2d (const int &n1, const int &n2)
template<class T>
void	free_2d (T **ii)
template<class T>
void	vrdft (int n, int isgn, vector< T > &a, int *ip, T *w)
template<class T>
void	rdft (int n, int isgn, T *a, int *ip, T *w)
template<class T>
void	cdft (int n, int isgn, T *a, int *ip, T *w)

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Detailed Description

Namespace with all FFT and inverse FFT routines based on code by Takuya Ooura with kind permission ooura@kurims.kyoto-u.ac.jp or ooura@mmm.t.u-tokyo.ac.jp).

The code has been adapted to use C++ and LTI-lib conventions. This functions will be used by the functors lti::realFFT and lti::realInvFFT

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Function Documentation

template<class T> T* lti::fft::alloc_1d (  const int &  n1  )

reserve memory for a n-dimensional vector of elements with type T Parameters: n1  dimension of the vector Returns: pointer to the elements of the vector

template<class T> T** lti::fft::alloc_2d (  const int &  n1, const int &  n2 )

reserve memory for a n1xn2-matrix of elementes of type T Parameters: n1  number of rows n2  number of columns Returns: pointer to the elements of the vector

template<class T> void lti::fft::cdft (  int  n, int  isgn, T *  a, int *  ip, T *  w )

complex direct fourier transform Parameters: n  data length (must be power of 2) isgn  transform direction: +1 for transform and -1 for inverse. a  the input/output data. In the frecuency domain the real parts will be stored in the even locations and the imaginary parts in the odd locations. a[1] = real[n/2] ip  work area for bit reversal. ip[0] and ip[1] are pointers to cos/sin table w  cos/sin table. w[] and ip[] will be initialized if ip[0] == 0

template<class T> void lti::fft::free_1d (  T *  i  )

free memory of 1d array of elements with type T

template<class T> void lti::fft::free_2d (  T **  ii  )

free memory of 2d array of elements with type T

template<class T> void lti::fft::rdft (  int  n, int  isgn, T *  a, int *  ip, T *  w )

real discrete fourier transform Parameters: n  data length (must be power of 2) isgn  transform direction: +1 for transform and -1 for inverse. a  the input/output data. In the frecuency domain the real parts will be stored in the even locations and the imaginary parts in the odd locations. a[1] = real[n/2] ip  work area for bit reversal. ip[0] and ip[1] are pointers to cos/sin table w  cos/sin table. w[] and ip[] will be initialized if ip[0] == 0

template<class T> void lti::fft::vrdft (  int  n, int  isgn, vector< T > &  a, int *  ip, T *  w )

real discrete fourier transform for lti::vectors Parameters: n  data length (must be power of 2) isgn  transform direction: +1 for transform and -1 for inverse. a  the input/output data. In the frecuency domain the real parts will be stored in the even locations and the imaginary parts in the odd locations. a[1] = real[n/2] ip  work area for bit reversal. ip[0] and ip[1] are pointers to cos/sin table w  cos/sin table. 3 w[] and ip[] will be initialized if ip[0] == 0

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