Hi, I tried on this, but couldn't figure it out: Suppose I have a dataframe as follows: dat <- data.frame(Day=rep(rep(c(1,2), each=4),2), Animal = rep(c(1,2), each=8), Count=c(rnorm(8, 100), rnorm(8,90)))
2 animals are being examined on 2 different days. Count is the result. Now I need to point out whether or not there is a difference between the days. I did this by an ANOVA test, while first converting the animal and day to a factor variable: dat$Animal <- as.factor(dat$Animal) dat$Day <- as.factor(dat$Day) mod <- lm(Count ~Animal * Day,dat) anova(mod) Now I have to check for difference within the animal, to see if there is a difference in count for each day. (In my real data, I have 35 animals, with 4 days, and 4 results). I thought about a Tukey HSD test, but this compares every day of every animal with every other day of every other animal. (TukeyHSD(aov(mod))) Any idea about which function (or model for lm) to use to only compare days within every animal? Best regards Bart -- View this message in context: http://r.789695.n4.nabble.com/Help-with-seting-up-comparison-tp2246106p2246106.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
