Hi: Try this:
test.summary[[1]][, 5] It should return a vector of p-values, the last being NA. In your case, since there is only one non-NA p-value, it is enough to do test.summary[[1]][, 5][1] You mean that wasn't obvious? :) Explanation: summary(aovobj) actually returns a list, but that's not obvious from looking at the print method. If you ask for its names, as in names(summary(aovobj)), it returns NULL, further adding to the confusion. However, since it is a list, summary(aovobj)[[1]] returns the ANOVA table, and ANOVA tables in R's modeling functions are typically matrices. The model terms are the rownames of the matrix (although that isn't obvious at first, either). That being the case, the p-values are in column 5 (whose column name is 'Pr(>F)' ), so we can extract that column with summary(aovobj)[[1]][, 5] or summary(aovobj)[[1]][, 'Pr(>F)'] To get the first element of that p-value vector, use summary(aovobj)[[1]][, 5][1] HTH, Dennis On Wed, Sep 29, 2010 at 3:47 AM, syrvn <ment...@gmx.net> wrote: > > Hi, > > I did a aov and used summary to obtain the p-value. I tried many ways to > extract the p-value from > the summary result but failed. Among others I tried the following: > > > > > test.summary <- > > summary(aov(data[,1]~time.points+Error(subject/time.points))) > > test.summary > > Error: subject > Df Sum Sq Mean Sq F value Pr(>F) > Residuals 9 0.27467 0.030518 > > Error: subject:time.points > Df Sum Sq Mean Sq F value Pr(>F) > time.points 2 0.018563 0.0092814 3.1777 0.06578 . > Residuals 18 0.052574 0.0029208 > --- > Signif. codes: 0 *** 0.001 ** 0.01 * 0.05 . 0.1 1 > > > > as.matrix(test.summary[[1]][,5]) > Error in `[.default`(test.summary[[1]], , 5) : > incorrect number of dimensions > > test.summary$"Error: Within"[[1]]$"Pr(>F)" > NULL > > test.summary[[2]][,5] > Error in `[.default`(test.summary[[2]], , 5) : > incorrect number of dimensions > > > > > Any advise? > Cheers > -- > View this message in context: > http://r.789695.n4.nabble.com/Problems-extracting-p-value-from-summary-aov-tp2718726p2718726.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. > [[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.
