choplump-package {choplump} | R Documentation |
This package has basically one important function, choplump
for performing the choplump test,
which is for comparing two groups with some positive response and many zero responses. These tests can often be
more powerful than simpler permutation tests. Exact and approximation methods are available for calculating p-values.
Package: | choplump |
Type: | Package |
Version: | 0.9-1 |
Date: | 2007-08-06 |
License: | GPL |
See example below. There is also two vignettes. The vignette computation
(see vignette("choplumpComputation")
)
gives computational details, and the vignette validation (see vignette("choplumpValidation")
) details the
way we have validated the function.
Michael P. Fay
Maintainer: M.P. Fay <mfay@niaid.nih.gov>
Follmann, DA, Fay, MP, and Proschan, MA. ''Chop-lump tests for Vaccine trials'' (unpublished manuscript, see /doc/choplump.pdf)
set.seed(13921) Ntotal<-200 Mtotal<-54 Z<-rep(0,Ntotal) Z[sample(1:Ntotal,Ntotal/2,replace=FALSE)]<-1 test<-data.frame(W=c(rep(0,Ntotal-Mtotal),abs(rnorm(Mtotal))),Z=Z) ## defaults to asymptotic approximation if the number of calculations of the test statistic is >methodRuleParms=10^4 choplump(W~Z,data=test,use.ranks=TRUE,exact=FALSE)