Created
July 24, 2022 10:56
-
-
Save argahsuknesib/185daef95343dc11ceba51654f6af4db to your computer and use it in GitHub Desktop.
PostHoc tests
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
posthoc.tgh <- function(y, x, method=c("games-howell", "tukey"), digits=2) { | |
### Based on http://www.psych.yorku.ca/cribbie/6130/games_howell.R | |
method <- tolower(method); | |
tryCatch(method <- match.arg(method), error=function(err) { | |
stop("Argument for 'method' not valid!"); | |
}); | |
res <- list(input = list(x=x, y=y, method=method, digits=digits)); | |
res$intermediate <- list(x = factor(x[complete.cases(x,y)]), | |
y = y[complete.cases(x,y)]); | |
res$intermediate$n <- tapply(y, x, length); | |
res$intermediate$groups <- length(res$intermediate$n); | |
res$intermediate$df <- sum(res$intermediate$n) - res$intermediate$groups; | |
res$intermediate$means <- tapply(y, x, mean); | |
res$intermediate$variances <- tapply(y, x, var); | |
res$intermediate$pairNames <- combn(levels(res$intermediate$x), | |
2, paste0, collapse=":"); | |
res$intermediate$descriptives <- cbind(res$intermediate$n, | |
res$intermediate$means, | |
res$intermediate$variances); | |
rownames(res$intermediate$descriptives) <- levels(res$intermediate$x); | |
colnames(res$intermediate$descriptives) <- c('n', 'means', 'variances'); | |
### Start on Tukey | |
res$intermediate$errorVariance <- | |
sum((res$intermediate$n-1) * res$intermediate$variances) / | |
res$intermediate$df; | |
res$intermediate$t <- combn(res$intermediate$groups, 2, function(ij) { | |
abs(diff(res$intermediate$means[ij]))/ | |
sqrt(res$intermediate$errorVariance*sum(1/res$intermediate$n[ij])); | |
} ); | |
res$intermediate$p.tukey <- ptukey(res$intermediate$t*sqrt(2), | |
res$intermediate$groups, | |
res$intermediate$df, | |
lower.tail=FALSE); | |
res$output <- list(); | |
res$output$tukey <- cbind(res$intermediate$t, | |
res$intermediate$df, | |
res$intermediate$p.tukey) | |
rownames(res$output$tukey) <- res$intermediate$pairNames; | |
colnames(res$output$tukey) <- c('t', 'df', 'p'); | |
### Start on Games-Howell | |
res$intermediate$df.corrected <- combn(res$intermediate$groups, 2, function(ij) { | |
sum(res$intermediate$variances[ij] / | |
res$intermediate$n[ij])^2 / | |
sum((res$intermediate$variances[ij] / | |
res$intermediate$n[ij])^2 / | |
(res$intermediate$n[ij]-1)); | |
} ); | |
res$intermediate$t.corrected <- combn(res$intermediate$groups, 2, function(ij) { | |
abs(diff(res$intermediate$means[ij]))/ | |
sqrt(sum(res$intermediate$variances[ij] / | |
res$intermediate$n[ij])); | |
} ); | |
res$intermediate$p.gameshowell <- ptukey(res$intermediate$t.corrected*sqrt(2), | |
res$intermediate$groups, | |
res$intermediate$df.corrected, | |
lower.tail=FALSE) | |
res$output$games.howell <- cbind(res$intermediate$t.corrected, | |
res$intermediate$df.corrected, | |
res$intermediate$p.gameshowell); | |
rownames(res$output$games.howell) <- res$intermediate$pairNames; | |
colnames(res$output$games.howell) <- c('t', 'df', 'p'); | |
### Set class and return object | |
class(res) <- 'posthocTukeyGamesHowell'; | |
return(res); | |
} | |
print.posthocTukeyGamesHowell <- function(x, digits=x$input$digits, ...) { | |
print(x$intermediate$descriptives, digits=digits); | |
cat('\n'); | |
if (x$input$method == 'tukey') { | |
print(x$output$tukey); | |
} | |
else if (x$input$method == 'games-howell') { | |
print(x$output$games.howell, digits=digits); | |
} | |
} | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment