Hi JesperHybel, Thanks for your advice.
>If you're trying to follow the youtube video you have a typing mistake here: >InsectSprays.aov <-(test01$count ~ test01$spray) >I think this should be: >InsectSprays.aov <-aov(test01$count ~ test01$spray) Your advice works for me. Sorry I missed "aov" before(test01$count ~ test01$spray) > InsectSprays.aov <- aov(test01$count ~ test01$spray) > summary(InsectSprays.aov) Df Sum Sq Mean Sq F value Pr(>F) test01$spray 5 2668.8 533.77 34.702 < 2.2e-16 *** Residuals 66 1015.2 15.38 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > TukeyHSD(InsectSprays.aov) Tukey multiple comparisons of means 95% family-wise confidence level Fit: aov(formula = test01$count ~ test01$spray) $`test01$spray` diff lwr upr p adj B-A 0.8333333 -3.866075 5.532742 0.9951810 C-A -12.4166667 -17.116075 -7.717258 0.0000000 D-A -9.5833333 -14.282742 -4.883925 0.0000014 E-A -11.0000000 -15.699409 -6.300591 0.0000000 F-A 2.1666667 -2.532742 6.866075 0.7542147 C-B -13.2500000 -17.949409 -8.550591 0.0000000 D-B -10.4166667 -15.116075 -5.717258 0.0000002 E-B -11.8333333 -16.532742 -7.133925 0.0000000 F-B 1.3333333 -3.366075 6.032742 0.9603075 D-C 2.8333333 -1.866075 7.532742 0.4920707 E-C 1.4166667 -3.282742 6.116075 0.9488669 F-C 14.5833333 9.883925 19.282742 0.0000000 E-D -1.4166667 -6.116075 3.282742 0.9488669 F-D 11.7500000 7.050591 16.449409 0.0000000 F-E 13.1666667 8.467258 17.866075 0.0000000 I made a comparison of my result with "example(InsectSprays). They looks the same. I also compared "plot(InsectSprays.aov)". A further question how to plot 4 graphs simultaneously? Instead of reading them, individually. I read ?plot but unable to resolve. Also how to save InsectSprays.aov? I think I can only save it as InsectSprays.csv. I can't find "write.aov" command. Thanks TIA B.R. satimis ----- Original Message ---- From: JesperHybel <jesperhy...@hotmail.com> To: r-help@r-project.org Sent: Sat, August 14, 2010 2:09:48 AM Subject: Re: [R] Learning ANOVA If you're trying to follow the youtube video you have a typing mistake here: InsectSprays.aov <-(test01$count ~ test01$spray) I think this should be: InsectSprays.aov <-aov(test01$count ~ test01$spray) youre missing the functioncall "aov" on the right hand side of the assignment operator '<-'. the results of the application of function aov() is stored in InsectSprays.aov and is accessed through summary(InsectSprays.aov) since you missed the functioncall you cannot apply TukeyHSD() to InsectSprays.aov I think -- View this message in context: http://r.789695.n4.nabble.com/Learning-ANOVA-tp2323660p2324590.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. ______________________________________________ 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.