R Users, We would like to announce that Version 1.0.1 of the energy package is now available on CRAN. The energy package introduces a new class of statistical tests based on the concept of Newton's potential energy. Included in the package are * mvnorm.etest (test) and mvnorm.e (statistic) A rotation invariant multivariate goodness-of-fit test, implemented for testing multivariate normality with estimated parameters * eqdist.etest (test) and ksample.e (statistic) A k-sample multivariate nonparametric test of equal distributions (arbitrary number of samples and arbitrary dimension) with optional incomplete statistics to support testing arbitrarily large samples * energy.hclust and edist Hierarchical clustering based on e-distances and cluster distance function * poisson.mtest (test) and poisson.m (statistic) Mean distance test of Poisson distribution, estimated mean Here is a brief summary of the potential energy background of the tests in the energy package: Newton's gravitational force is inversely proportional to squared Euclidean distances between pairs of objects, and the potential energy is inversely proportional to their Euclidean distances. The simplest choice for the absolute value of the force is constant, and then the potential energy is proportional to the Euclidean distances between pairs of objects. In statistics, the objects are the observed random vectors, and thus our energy terms are Euclidean distances between the pairs of sample elements: ||x_i - x_j||. Tests are based on the Theorem that a suitable linear combination of these distances (the potential energy of the 'statistical situation') is always nonnegative, and equals 0 if and only if the null hypothesis holds. Comments and suggestions are welcome. The description file is below. Gabor Szekely and Maria Rizzo ---------------------------------------------------------------------- Description: Package: energy Title: E-statistics (energy statistics) tests of fit, clustering Version: 1.0.1 Date: March 24, 2004 Author: Maria L. Rizzo <rizzo at math.ohiou.edu> and Gabor J. Szekely <gabors at bgnet.bgsu.edu> Description: E-statistics (energy) tests for comparing distributions: multivariate normality, Poisson test, multivariate k-sample test for equal distributions, hierarchical clustering by e-distances. Energy-statistics concept based on a generalization of Newton's potential energy is due to Gabor J. Szekely. Maintainer: Maria Rizzo <rizzo at math.ohiou.edu> License: GPL 2.0 or later -- **************************************** Gabor J. Szekely Professor Department of Mathematics and Statistics Math Science Building Bowling Green State University Bowling Green, OH 43403-0221 E-mail: gabors at bgnet.bgsu.edu Tel: 419-372-7474 Fax: 419-372-6092 http://www-math.bgsu.edu/~gabors/ _______________________________________________ R-packages mailing list R-packages at stat.math.ethz.ch https://www.stat.math.ethz.ch/mailman/listinfo/r-packages