LPCM (version 0.43)

LPCM-package: Local principal curve methods

Description

Fitting multivariate data patterns with local principal curves; including simple tools for data compression (projection), bandwidth selection, and measuring goodness-of-fit.

This package implements the techniques introduced in Einbeck, Tutz & Evers (2005), and successive related papers.

The main functions to be called by the user are

• lpc, for the estimation of the local centers of mass which make up the principal curve;
• lpc.spline, which is a smooth and fully parametrized cubic spline respresentation of the latter;
• lpc.project, which enables to compress data by projecting them orthogonally onto the curve;
• lpc.coverageandlpc.Rcfor assessing goodness-of-fit;
• lpc.self.coveragefor bandwidth selection;
• the genericplotandprintfunctions for objects of classlpcandlpc.spline.

This package also contains some code for density mode detection and mean shift clustering (as well as bandwidth selection in this context), which implements the methods presented in Einbeck (2011). See the help file for ms.

A second R package which will implement the extension of local principal curves to local principal surfaces and manifolds, as proposed in Einbeck, Evers & Powell (2010), is in preparation.

Details

ll{ Package: LPCM Type: Package License: GPL 2.0 or newer. LazyLoad: yes }

References

Einbeck, J., Tutz, G., & Evers, L. (2005), Local principal curves, Statistics and Computing 15, 301-313.

Einbeck, J., Evers, L., & Powell, B. (2010): Data compression and regression through local principal curves and surfaces, International Journal of Neural Systems, 20, 177-192.

Einbeck, J. (2011): Bandwidth selection for nonparametric unsupervised learning techniques -- a unified approach via self-coverage. Journal of Pattern Recognition Research, to appear.

See Also

pcurve, princurve