Principal component analysis – Multichannel Systems NeuroExplorer User Manual

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2.25. Principal Component Analysis


This analysis calculates eigenvalues and eigenvectors (principal components) of the matrix of
correlations of rate histograms. The analysis creates

population vectors

corresponding to the principal

components.

Parameters

Parameter

Description

Bin

Bin size in seconds.

Vectors Prefix

A string specifying how the population vector names will be generated. For
example, if prefix is pca1, the vector names will be pca1_01, pca1_02,
etc.

Select Data

If Select Data is From Time Range, only the data from the specified (by
Select Data From and Select Data To parameters) time range will be used
in analysis. See also

Data Selection Options

.

Select Data From

Start of the time range in seconds.

Select Data To

End of the time range in seconds.

Interval filter

Specifies the interval filter that will be used to preselect data before
analysis. See also

Data Selection Options

.

Send to Matlab

An option to send the matrix of numerical results to Matlab. See also

Matlab Options

.

Matrix Name

Specifies the name of the results matrix in Matlab workspace.

Matlab command

Specifies a Matlab command that is executed after the numerical results
are sent to Matlab.

Send to Excel

An option to send numerical results or summary of numerical results to
Excel. See also

Excel Options

.

Sheet Name

The name of the worksheet in Excel where to copy the numerical results.

TopLeft

Specifies the Excel cell where the results are copied. Should be in the form
CR where C is Excel column name, R is the row number. For example, A1
is the top-left cell in the worksheet.

Summary of Numerical Results


The following information is available in the Summary of Numerical Results

Column

Description

Variable

Variable name and PCA statistics name.

pca1_N

The weight of the variable in the N-th eigenvector. The rows at the bottom
of the table also show Eigenvalue of this eigenvector, % of variance it
explains, and the cumulative percent of the variance explained by this and
preceding eigenvectors.

Corr with VAR

Correlation with the specified variable.

Numerical Results

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