Yes, that works fine too. It likely depends on what you want to show and to whom. The audience might be ready to see the equivalence between t-tests and anova(lm(...)) but not yet prepared for variance components.
- Peter > On 27 Dec 2022, at 18:55 , Greg Snow <538...@gmail.com> wrote: > > Why compute the differences manually when `aov` can do paired > comparisons on this data as is: > > summary(aov(extra ~ factor(group) + Error(ID), data=sleep )) > > gives the same F and P values > > On Tue, Dec 27, 2022 at 3:32 AM Gabor Grothendieck > <ggrothendi...@gmail.com> wrote: >> >> Good idea. >> >> On Mon, Dec 26, 2022 at 12:59 PM peter dalgaard <pda...@gmail.com> wrote: >>> >>> My usual advice on getting nonstandard F tests out of anova() is to fit the >>> models explicitly and compare. >>> >>> So how about this? >>> >>> fit1 <- lm(diff(extra,10) ~ 1, sleep) >>> fit0 <- update(fit1, ~ -1) >>> anova(fit0, fit1) >>> >>> -pd >>> >>>> On 26 Dec 2022, at 13:49 , Gabor Grothendieck <ggrothendi...@gmail.com> >>>> wrote: >>>> >>>> Suppose we want to perform a paired test using the sleep data frame >>>> with anova in R. Then this works and gives the same p value as >>>> t.test(extra ~ group, sleep, paired = TRUE, var.equal = TRUE) >>>> >>>> ones <- rep(1, 10) >>>> anova(lm(diff(extra, 10) ~ ones + 0, sleep) >>>> >>>> This gives output but does not give an F test at all. >>>> >>>> ones <- rep(1, 10) >>>> anova(lm(diff(extra, 10) ~ 1, sleep) >>>> >>>> Maybe there should be some way to force an F test to be produced for >>>> the intercept in anova for consistency with t.test so that the second >>>> code can be used. >>>> >>>> >>>> -- >>>> Statistics & Software Consulting >>>> GKX Group, GKX Associates Inc. >>>> tel: 1-877-GKX-GROUP >>>> email: ggrothendieck at gmail.com >>>> >>>> ______________________________________________ >>>> R-devel@r-project.org mailing list >>>> https://stat.ethz.ch/mailman/listinfo/r-devel >>> >>> -- >>> Peter Dalgaard, Professor, >>> Center for Statistics, Copenhagen Business School >>> Solbjerg Plads 3, 2000 Frederiksberg, Denmark >>> Phone: (+45)38153501 >>> Office: A 4.23 >>> Email: pd....@cbs.dk Priv: pda...@gmail.com >>> >> >> >> -- >> Statistics & Software Consulting >> GKX Group, GKX Associates Inc. >> tel: 1-877-GKX-GROUP >> email: ggrothendieck at gmail.com >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel > > > > -- > Gregory (Greg) L. Snow Ph.D. > 538...@gmail.com -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
