Thank you for the correction and the code. I had just discovered the repeated measure error myself yesterday :-). I had not thought of using a manova. This may work better than what I was going to do. Thanks again. ----- Original Message -----
> From: "c06n [via R]" <ml-node+s789695n4706293...@n4.nabble.com> > To: "Darcy Trimpe" <darcy.m.tri...@wmich.edu> > Sent: Thursday, April 23, 2015 2:47:35 AM > Subject: Re: Two Factorial Experiment with a Single Control Group > Hi, > do you mean you didn't take any measurements before treatment, only > after the fact? If so you used an inappropriate design. > It should have been a repeated measures design ( > https://en.wikipedia.org/wiki/Repeated_measures_design ) and looked > like this: > no treatment | acute | 3 weeks > day 1 measurement t1 | measurement t1 | measurements t1 > ... > day 27 measurement t2 | measurement t2 | measurement t2 > Coming back to your question: Of course you can test the group > differences from the measurements with a MANOVA ( > https://en.wikipedia.org/wiki/Multivariate_analysis_of_variance , > http://statmethods.net/stats/anova.html ). Treatment (acute, 3 week, > no treatment) would be the 3-level-factor. > Below the R code: > # make data frame > dataset <- data.frame( > "treatment" = c("acute", "acute", "acute", > "3weeks", "3weeks", "3weeks", > "no", "no", "no"), > "noTX" = c(7, 5, 4, 21, 28, 26, 3, 4, 7), > "TX" = c(9, 8, 7, 23, 27, 29, 2, 5, 9), > stringsAsFactors = TRUE > ) > # plot > # http://www.statmethods.net/advgraphs/ggplot2.html > install.packages("ggplot2") > require(ggplot2) > p1 <- qplot(treatment, noTX, data = dataset, geom = c("boxplot", > "jitter"), > fill = treatment, main = "noTX", ylab = "Value") > p2 <- qplot(treatment, TX, data = dataset, geom = c("boxplot", > "jitter"), > fill = treatment, main = "TX", ylab = "Value") > p1; p2 > # MANOVA > # http://statmethods.net/stats/anova.html > # > http://cran.r-project.org/web/packages/HSAUR/vignettes/Ch_analysis_of_variance.pdf > fit <- manova(cbind(noTX, TX) ~ treatment, data = dataset) > summary(fit) > If you reply to this email, your message will be added to the > discussion below: > http://r.789695.n4.nabble.com/Two-Factorial-Experiment-with-a-Single-Control-Group-tp4706153p4706293.html > To unsubscribe from Two Factorial Experiment with a Single Control > Group, click here . > NAML -- View this message in context: http://r.789695.n4.nabble.com/Two-Factorial-Experiment-with-a-Single-Control-Group-tp4706153p4706299.html Sent from the R help mailing list archive at Nabble.com. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
