Is it possible to implement the Jonckheere-Terpstra test for ordered alternatives using the coin package: Conditional Inference Procedures in a Permutation Test Framework?
I found jonckheere.test{clinfun}, but it uses a normal approximation when ties are present in the data. To make this concrete, I've include a small dataset. Thanks. --Dale Hollander and Wolfe, 1999 Table 6.6, pg 205 control <- c(40, 35, 38, 43, 44, 41) rough <- c(38, 40, 47, 44, 40, 42) accurate <- c(48, 40, 45, 43, 46, 44) pieces <- list(control, rough, accurate) n <- c(6, 6, 6) grp <- as.ordered(factor(rep(1:length(n),n))) library(clinfun) jonckheere.test(unlist(pieces), grp, alternative="increasing") Output below ... > jonckheere.test(unlist(pieces), grp, alternative="increasing") Jonckheere-Terpstra test data: JT = 79, p-value = 0.02163 alternative hypothesis: increasing Warning message: In jonckheere.test(unlist(pieces), grp, alternative = "increasing") : TIES: p-value based on normal approximation ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.