phyper returns 1 if x==k (PR#8499)
On Wed, 18 Jan 2006 utz.pape at molgen.mpg.de wrote:
Full_Name: Utz J. Pape Version: 2.2.0 OS: linux Submission from: (NULL) (141.14.23.12) If I use phyper and set parameter x equal to k (meaning that all balls I draw are white) phyper returns 1 which is not (always) correct:
I think you are confusing this with dhyper. How can you possibly get more white balls than exist in the urn? That you cannot is what p = 1 is telling you. We do quite specifically ask you not to report on obselete versions of R. Of course, as this is NOT A BUG, it is the same in the current R.
pape at xxx:~> R2.2.0 --vanilla R : Copyright 2005, The R Foundation for Statistical Computing Version 2.2.0 (2005-10-06 r35749) ISBN 3-900051-07-0 R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for a HTML browser interface to help. Type 'q()' to quit R.
x <- 10; m <- 20; n <- 5; k <- 10 phyper(x,m,n,k)
[1] 1
choose(m,x) * choose(n,k-x) / choose(m+n,k)
[1] 0.05652174
version
_ platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status major 2 minor 2.0 year 2005 month 10 day 06 svn rev 35749 language R
sessionInfo()
R version 2.2.0, 2005-10-06, i686-pc-linux-gnu attached base packages: [1] "methods" "stats" "graphics" "grDevices" "utils" "datasets" [7] "base"
______________________________________________ R-devel at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595