Helo everybody, I'm new to R and have some issues with my data in R. My raw data look like that:
ID Day size 1 1 7 1 1 7.2 1 1 7.1 2 1 7.3 2 1 7.4 2 1 7.2 3 1 7 3 1 7.1 3 1 7.5 4 1 7.3 4 1 7.2 4 1 7.6 1 2 7 1 2 7.2 1 2 7.1 2 2 7.1 2 2 7.4 2 2 7.2 3 2 7.5 3 2 7.1 3 2 7.5 4 2 7.2 4 2 7.2 4 2 7.3 1 3 7.4 1 3 7.2 1 3 7.1 2 3 7.2 2 3 7.4 2 3 7.2 3 3 7.4 3 3 7.2 3 3 7.5 4 3 7.4 4 3 7.2 4 3 7.7 What I want to do is: 1) calculate the significant difference of the size for the 4 groups but each day separately!)? E.g. difference in size between ID 1:2, 1:3, 1:4, 2:3, 2:4, 3:4 for each day. I already tried lm() and anova() but just get the difference between day, ID and size. I also tried to separate the data per hand but I think there should be a way in "R" to do that automatically!? Moreover, I was searching the web for similar examples but couln't find anything useful so far. 2) to make a barplot with error bars of the standart error (from the mean). So far I used: barplot(matrix(c(Rtest.dat$pH.mean),nr=3), beside=T, col=c("black","grey","white"), main="pH", names.arg=c("Green", "Yellow", "Blue", "Red"), ylab="pH") legend("topright", c("Day 1","Day 2","Day 3"), cex=0.6, bty="n", fill=c("black","grey","white")) But I have problems to add the error bars. Also here I already searched the web but couldn't manage to get a code working for my data. 3) and the last thing I would need is to add * or letters (a,b,...) to the graph, indicating the significant difference between them. Hope someone can help me! Thanks for your help!! -- View this message in context: http://r.789695.n4.nabble.com/Make-barplot-with-error-bars-anova-out-of-a-table-tp4663979.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.