parraycovarmat

Calculates covariance matrix of arrays items.

Synopsis

parraycovarmat name_in name_out [col_in|-] [col_out|-]

Description

parraycovarmat calculates:

the covariance matrix A,
the inverse covariance matrix A^-1,
the determinant, and the mean array

from a set of arrays in the input collection col_in.

If there exists n arrays of p values each, the input collection col_in must contains p arrays name_in.1, name_in.2, ..., name_in.p of n float values each.

Parameters

name_in specifies the base name of the array from which the covariance matrix will be calculated. It is a string without blank character.
name_out is the base name of the output arrays:
- name_out.mat : p*p covariance matrix.
- name_out.inv : p*p inverse covariance matrix.
- name_out.det : the determinant.
- name_out.mean : mean array of p values.

Inputs

col_in: a collection.

Outputs

col_out: a collection.

Result

Returns SUCCESS or FAILURE.

Examples

Classifies beans into the jellybean.pan image from sample of each bean stored in the directory 'base' (Unix version).

# Learning
classes=1
for i in base/*.pan
do
    pim2array ind $i /tmp/tmp1 
    parray2array ind.1 Float /tmp/tmp1| parray2array ind.2 Float | parray2array ind.3 Float - a.pan
    parraycovarmat ind ind a.pan i-01.pan
    if [ -f base.pan ]
    then pcolcatenateitem i-01.pan base.pan base.pan
    else cp i-01.pan base.pan
    fi
    classes=`expr $classe + 1`
done
rm /tmp/tmp1

# Classification
pim2array ind jellybeans.pan a.pan
parray2array ind.1 Float a.pan| parray2array ind.2 Float | parray2array ind.3 Float - b.pan
pgaussclassification ind ind ind base.pan b.pan | parray2im $ncol $nrow 0 ind | pim2rg - out.pan

C++ prototype

Errc PArrayCovarMat( const Collection &col_in, , Collection &col_out, const std::string &name_in, const std::string &name_out );

Version française

Calcul de la matrice de covariance associée à un ensemble d'éléments.

Author: Alexandre Duret-Lutz