Hi Erik,
I followed following video as example; ANOVA in R http://www.youtube.com/watch?v=Dwd3ha0P8uw&feature=related Now I got it done; > boxplot(test01$count ~ test01$spray) Continued: > InsectSprays.aov <-(test01$count ~ test01$spray) > summary(InsectSprays.aov) Length Class Mode 3 formula call Seems having problem here. > TukeyHSD(InsectSprays.aov) Error in UseMethod("TukeyHSD") : no applicable method for 'TukeyHSD' applied to an object of class "formula" I'm still stuck here. B.R. Stephen L ----- Original Message ---- From: Erik Iverson <er...@ccbr.umn.edu> To: Stephen Liu <sati...@yahoo.com> Cc: r-help@r-project.org Sent: Sat, August 14, 2010 12:15:31 AM Subject: Re: [R] Learning ANOVA > Performed following steps on R:- > > ### to access to the object >> data(InsectSprays) > > ### create a .csv file >> write.csv(InsectSprays, "InsectSpraysCopy.csv") > > > On another terminal > $ sudo updatedb > $ locate InsectSpraysCopy.csv > /home/userA/InsectSpraysCopy.csv > > > ### Read in some data >> test01 <- read.csv(file.choose(), header=TRUE) > > Enter file name: /home/userA/InsectSpraysCopy.csv I either don't understand what you're doing, or you seem very confused. R comes with many sample data sets for you to use. You can see a list of them using the ?data function. Calling data with an argument loads that dataset. So, when you type: > data(InsectSprays) that data object is now available in R, see > objects() You can look at it simply by printing it: > InsectSprays If for some reason it makes sense to do it this way for your use case, then that's fine, I just want to make sure you understand that you don't have to if accessing built-in datasets is all you want. > ### Look at the data >> test01 > X count spray > 1 1 10 A > 2 2 7 A > 3 3 20 A <snip> > ### Create a side-by-side boxplot of the data > boxplot(test01$DO ~ test01$Stream) > Error in model.frame.default(formula = test01$DO ~ test01$Stream) : invalid >type (NULL) for variable 'test01$DO' Why do you think test01 has an element called "D0" or "Stream"?? The column names when you print the data tell you otherwise! ______________________________________________ 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.
