Exteriorpts

Purpose

Finds pts on the exterior of a data space after data are normalized.

Synopsis

[loads,isel] = exteriorpts(x,ncomp,options)

Description

The data (X) are assumed to be all >0 and to be modelable as: X = CS' + E

Inputs

• x = MxN matrix.
• ncomp = number of components to extract.

Outputs

• loads = cell array with extracted pts/factors. Non-selectdim modes are determined via projection.
• isel = cell array with isel{options.selectdim} containing indices of selected pts.

Options

options = a structure array with the following fields:

• display : [ 'off' | {'on'} ] governs level of display to command window.
• samplemode : [ 1 ] mode that contains variance (factors for other modes are normalized to unit 2-norm).
• distmeasure : [ {'Euclidian'} | 'Mahalanobis' ]
• minnorm : [ 0.03 ] approximate noise level, points with 1-Norm <minnorm*max(norm(x)) are not used.

See Also

als, mcr, parafac, purity, purityengine