classify.3

来自「speech signal process tools」· 3 代码 · 共 86 行

.\" Copyright (c) 1987 Entropic Speech, Inc.; All rights reserved
.\" @(#)classify.3	1.3 30 Apr 1997 ESI
.TH CLASSIFY 3\-ESPSsp 30 Apr 1997
.ds ]W "\fI\s+4\ze\h'0.05'e\s-4\v'-0.4m'\fP\(*p\v'0.4m'\ Entropic Speech, Inc.
.SH NAME
classify \- maximum-likelihood or maximum-posterior-probability classification
of feature vector
.SH SYNOPSIS
.ft B
.nf
int
classify(feavec, nfea, nclas, means, invcovars, priors, posteriors)
float	*feavec;
int	nfea, nclas;
float	**means, ***invcovars, *priors;
float	*posteriors;

.fi
.ft
.SH DESCRIPTION
.PP
.I Classify
classifies a vector
.I feavec
of
.I nfea
numerical features into one of
.I nclas
classes, where each class is represented by an
.IR nfea -element
mean vector, an
.IR nfea -by- nfea
inverse covariance matrix, and, for maximum-posterior-probability
classification, a prior probability.
.PP
The input arrays
.I means
and
.I invcovars
should each have
.I nclas
elements, as should
.I priors
for maximum-posterior-probability classification; for
maximum-likelihood classification,
.I priors
should be NULL.
For each index
.I c
in the range
.RI "(0 <= " c " < " nfea "),"
.IR means [ c ]
and
.IR invcovars [ c ]
should point to the mean vector and inverse covariance matrix for one
class, and
.IR priors [ c ],
if defined, should be the prior probability for the same class.
(More precisely,
.IR means [ c ]
points to the first element of the mean vector, and
.IR invcovars [ c ]
points to a pointer to the first row of the inverse covariance matrix.)
.PP
.I Posteriors
should point to the first element of an
.IR nfea -element
output vector, which will receive the posterior probabilities.
If
.I priors
is NULL, these are computed as though all priors had been specified as
.RI 1/ nclas.
.PP
The return value of
.I classify
is the index
.I c
for which the posterior probability is greatest.
How ties are broken is unspecified.
.SH BUGS
None known.
.SH "SEE ALSO"
\fIfea_stats\fR(1\-ESPS),  \fIf_mat_alloc\fR(3\-ESPSu), FEA_STAT(5\-ESPS)
.SH AUTHOR
Rodney Johnson