Hi Douglas. So you want to check for correlation or regression ? how many levels does "pre" have ? you could subset the variables you want to check correlation on, by the pre levels.
for example: Let's say pre has two levels: 1 and 2. then you can do: cor(y[pre == 1], x[pre == 1]) cor(y[pre == 2], x[pre == 2]) Also, If you want to go for regression, you can go to something like: summary(lm(y ~ x + pre)) But I suggest getting much more understanding of what linear regression is before using it's methods... Good luck, Tal On Sat, Apr 25, 2009 at 1:26 PM, drmh <douglasrmhol...@googlemail.com>wrote: > > Hi, thanks for your prompt reply > > In my situation, the dependent variable is "post-test" and the independent > variables are "pre" and "coh". > Howw would I find the correlation between coh and post with the effect of > "pre" regressed using your commands? > > > > Tal Galili wrote: > > > > Hi Douglas > > I would go for a different command then aov. > > something like: > > ?cor > > or > > ?cor.test > > To also get the p value of the correlation. > > > > Cheers, > > Tal > > > > > > > > On Sat, Apr 25, 2009 at 8:27 AM, drmh > > <douglasrmhol...@googlemail.com>wrote: > > > >> > >> (Have searched for this already) > >> > >> Hi, > >> > >> How do you find the strength of correlation between two variables using > >> an > >> ANOVA table? "Pr(>F)" gives the statistical significance of the > >> association, but not the strength of the correlation. > >> > >> See data (from R) below > >> > >> Readable: > >> "Df" "Sum Sq" "Mean Sq" "F > >> value" > >> "Pr(>F)" > >> "pre" 1 0.00593 0.00593936 > >> 0.7450563 0.401636958677004 > >> "coh" 1 0.04311 0.04311302 > >> 5.4082639 > >> 0.0344751749542619 > >> "Residuals" 15 0.11957 0.00797169 NA > >> NA > >> > >> Original: > >> "Df" "Sum Sq" "Mean Sq" "F value" "Pr(>F)" > >> "pre" 1 0.0059393604629317 0.0059393604629317 0.745056336657567 > >> 0.401636958677004 > >> "coh" 1 0.0431130207164516 0.0431130207164516 5.40826398359156 > >> 0.0344751749542619 > >> "Residuals" 15 0.119575396598395 0.00797169310655964 NA NA > >> > >> Any help would be greatly appreciated, > >> Douglas Holmes > >> -- > >> View this message in context: > >> > http://www.nabble.com/ANOVA-statistics-question-tp23231563p23231563.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. > >> > > > > > > > > -- > > ---------------------------------------------- > > > > > > My contact information: > > Tal Galili > > Phone number: 972-50-3373767 > > FaceBook: Tal Galili > > My Blogs: > > http://www.r-statistics.com/ > > http://www.talgalili.com > > http://www.biostatistics.co.il > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > > > > > -- > View this message in context: > http://www.nabble.com/ANOVA-statistics-question-tp23231563p23234421.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. > -- ---------------------------------------------- My contact information: Tal Galili Phone number: 972-50-3373767 FaceBook: Tal Galili My Blogs: http://www.r-statistics.com/ http://www.talgalili.com http://www.biostatistics.co.il [[alternative HTML version deleted]] ______________________________________________ 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.
