mvg_eval.c File Reference

Computations of gaussian probabilities with diagonal covariance. More...

Functions
void	spr_mvg_mg_prob (const float *data, const SprHmmMvgs *mvgs, int start, int stop)
void	spr_mvg_mg_floor (SprHmmMvgs *mvgs, int nsel, double logminout)
void	spr_mvg_mg_sort (double *pvec, int start, int stop, int top_n, int *index, double *ptop)

Detailed Description

Computations of gaussian probabilities with diagonal covariance.

Author

Jacques Duchateau

Date

20 Jan 1994

The basic formula for all computations is:

   S       = PROD(sigmas)
   lnprob  = -0.5 ( ovlen*ln(2PI) + 2.0*ln|S|
                                  + SUM( [(data-mu)/sigma]^2 )
   pvec[i] = exp(lnprob[i]) )

Revision History:

Jan 1994 - Jacques Duchateau

created from g_prob()

Apr 1994 - Jacques Duchateau

added mg_log_prob()

May 1994 - Jacques Duchateau

only top_n densities calculated in mg_prob

May 1994 - Jacques Duchateau

removed mvg_eval()

Aug 1994 - Jacques Duchateau

changed code to use logsigprod

Aug 1994 - Jacques Duchateau

removed mg_log_prob()

Aug 1994 - Jacques Duchateau

adapted for selected_gauss vector

Sep 1994 - Jacques Duchateau

max of pvec set in first place

Aug 1995 - Kris Demuynck

max of pvec no longer set in first place as another flooring mechanism is used

Aug 1995 - Jacques Duchateau

moved mg_floor() from output_prob.c to here

Aug 1995 - Jacques Duchateau

splitted up mg_prob() in mg_prob() (only probability calculation) and mg_sort() (selecting the largest probabilities)

Aug 1995 - Jacques Duchateau

changes for new hmm structures

Aug 2004 - Kris Demuynck

made mg_sort() more efficient + other small changes