str() is again your friend. > str(asummary) List of 2 $ Error: subject :List of 1 ..$ :Classes ‘anova’ and 'data.frame': 1 obs. of 5 variables: .. ..$ Df : num 9 .. ..$ Sum Sq : num 943 .. ..$ Mean Sq: num 105 .. ..$ F value: num NA .. ..$ Pr(>F) : num NA ..- attr(*, "class")= chr [1:2] "summary.aov" "listof" $ Error: subject:condition:List of 1 ..$ :Classes ‘anova’ and 'data.frame': 2 obs. of 5 variables: .. ..$ Df : num [1:2] 2 18 .. ..$ Sum Sq : num [1:2] 52.3 11.1 .. ..$ Mean Sq: num [1:2] 26.133 0.615 .. ..$ F value: num [1:2] 42.5 NA .. ..$ Pr(>F) : num [1:2] 1.52e-07 NA ..- attr(*, "class")= chr [1:2] "summary.aov" "listof" - attr(*, "class")= chr "summary.aovlist"
So asummary is a list, each element of which contains yet another list which in turn contains a single data frame element. So, asummary[[2]][[1]]$'F value'[1] gives you the F value of the condition effect. On Mon, Jun 1, 2009 at 9:12 PM, tsunhin wong <thjw...@gmail.com> wrote: > As another follow-up related to aov, I want to extract values > (Residual interaction mean square & interaction DF) from the results: > asummary<-summary(aov.recall) > The results are in a list() format with 3 lists, and contents within > each list are without "names". > > I am not able to do something like in other statistics such as in t.test: >>as.numeric(t.test(serie1,serie2,na.rm=TRUE)$statistic) > > What method should I use to extract, or is it simpler to write compute > the figures that I need directly in this case? > Thanks a lot! > > - John > > On Mon, Jun 1, 2009 at 7:08 PM, Mike Lawrence <mike.lawre...@dal.ca> wrote: >> On Mon, Jun 1, 2009 at 7:50 PM, tsunhin wong <thjw...@gmail.com> wrote: >>> But I have some follow-up questions: >>> 1. In aov, why IVs (subject & condition) cannot be in number format? >> >> Put simply, because that's the only way to obtain the values you >> observe in the paper you're reading. :Op Factorizing tells the ANOVA >> that the labels associated with each level of the factor aren't really >> meaningful. This is particularly evident in the case of Subject >> numbers, which (typically) have no numeric interpretation (Ss #6 is >> not 2 times Ss #3). The original authors' choice to treat condition as >> a factor was a less clear choice given that it clearly refers to a >> measurable ratio quantity (seconds). I presume the paper to which >> you're referring is the Masson & Loftus 1994 paper (be sure to read >> their 2003 follow-up and 2004 correction). In that case the authors >> come from a field where it's commonplace to treat even ratio >> independent variables as factored. >> >>> 2. Why I need to use factor() on IVs (subject & condition) but I >>> cannot use factor() on DV (recall)? >> >> As noted above, factoring prohibits R from interpreting the labels of >> a value as numerically meaningful, something you surely do not want to >> do with your DV in this example. >> >> >> -- >> Mike Lawrence >> Graduate Student >> Department of Psychology >> Dalhousie University >> >> Looking to arrange a meeting? Check my public calendar: >> http://tr.im/mikes_public_calendar >> >> ~ Certainty is folly... I think. ~ >> > -- Mike Lawrence Graduate Student Department of Psychology Dalhousie University Looking to arrange a meeting? Check my public calendar: http://tr.im/mikes_public_calendar ~ Certainty is folly... I think. ~ ______________________________________________ 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.
