This function is used by the 'oneway' function for oneway analysis of variance in case a user requests post-hoc tests using the Tukey or Games-Howell methods.
posthocTGH(y, x, method=c("games-howell", "tukey"), conf.level = 0.95, digits=2, p.adjust="holm", formatPvalue = TRUE)
- y has to be a numeric vector.
- x has to be vector that either is a factor or can be converted into one.
- Which post-hoc tests to conduct. Valid values are "tukey" and "games-howell".
- Confidence level of the confidence intervals.
- The number of digits to show in the output.
- Whether to format the p values according to APA standards (i.e. replace all values lower than .001 with '<.001'). This only applies to the printing of the object, not to the way the p values are stored in the object.
A list of three elements:
This function is based on a file that was once hosted at http://www.psych.yorku.ca/cribbie/6130/games_howell.R, but has been removed since. It was then adjusted for implementation in the
userfriendlyscience package. Jeffrey Baggett needed the confidence intervals, and so emailed them, after which his updated functions was used. In the meantime, it appears Aaron Schlegel (https://rpubs.com/aaronsc32) independently developed a version with confidence intervals and posted it on RPubs at https://rpubs.com/aaronsc32/games-howell-test.
### Compute post-hoc statistics using the tukey method posthocTGH(y=ChickWeight$weight, x=ChickWeight$Diet, method="tukey"); ### Compute post-hoc statistics using the games-howell method posthocTGH(y=ChickWeight$weight, x=ChickWeight$Diet);