I would like to add some more information concerning the patch C to the function choose() proposed in the email https://stat.ethz.ch/pipermail/r-devel/2009-December/056177.html
The patch uses transformations of choose(n, k), which are described in http://www.cs.cas.cz/~savicky/R-devel/formulas_choose.pdf The accuracy of the modified function choose(n, k) may be verified on randomly generated examples using Rmpfr package http://cran.at.r-project.org/web/packages/Rmpfr/index.html and the script http://www.cs.cas.cz/~savicky/R-devel/test_choose_2.R The output, which i obtained, is > source("test_choose_2.R") k <= 9 max rel err = 9.41734e-16 k <= 19 max rel err = 2.084412e-15 k <= 29 max rel err = 3.170754e-15 k <= 39 max rel err = 4.99284e-14 k <= 49 max rel err = 5.927749e-14 k <= 59 max rel err = 6.526895e-14 k <= 69 max rel err = 6.526895e-14 k <= 79 max rel err = 8.783232e-14 k <= 89 max rel err = 1.051950e-13 k <= 99 max rel err = 1.051950e-13 k <= 109 max rel err = 1.072878e-13 k <= 119 max rel err = 1.072878e-13 k <= 129 max rel err = 1.179829e-13 k <= 139 max rel err = 1.247080e-13 k <= 149 max rel err = 1.247080e-13 k <= 159 max rel err = 1.255064e-13 k <= 169 max rel err = 1.255064e-13 k <= 179 max rel err = 1.267402e-13 k <= 189 max rel err = 1.311689e-13 k <= 199 max rel err = 1.573155e-13 k <= 209 max rel err = 1.844756e-13 Patch C also passes make check-all in the current development version 2.11.0 (2010-02-01). I appreciate comments. Petr Savicky. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
