{ "id": "1306.5294", "version": "v2", "published": "2013-06-22T06:26:46.000Z", "updated": "2013-09-04T15:47:20.000Z", "title": "A Note on Computing Extreme Tail Probabilities of the Noncentral T Distribution with Large Noncentrality Parameter", "authors": [ "Viktor Witkovsky" ], "comment": "Preprint submitted to Acta Universitatis Palackianae Olomucensis, Facultas rerum naturalium, Mathematica, submitted June 21, 2013, revised September 4, 2013", "categories": [ "stat.CO" ], "abstract": "The noncentral $t$-distribution is a generalization of the Student's $t$-distribution. In this paper we suggest an alternative approach for computing the cumulative distribution function (CDF) of the noncentral $t$-distribution which is based on a direct numerical integration of a well behaved function. With a double-precision arithmetic, the algorithm provides highly precise and fast evaluation of the extreme tail probabilities of the noncentral $t$-distribution, even for large values of the noncentrality parameter $\\delta$ and the degrees of freedom $\\nu$. The implementation of the algorithm is available at the MATLAB Central, File Exchange: http://www.mathworks.com/matlabcentral/fileexchange/41790-nctcdfvw.", "revisions": [ { "version": "v2", "updated": "2013-09-04T15:47:20.000Z" } ], "analyses": { "subjects": [ "62E15", "62-04" ], "keywords": [ "computing extreme tail probabilities", "large noncentrality parameter", "distribution", "matlab central", "large values" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1306.5294W" } } }