Dear Peter, On Mon, 5 Mar 2012 17:28:32 +0100 peter dalgaard <pda...@gmail.com> wrote: > > On Mar 5, 2012, at 16:05 , Tamre Cardoso wrote: > > > Thank you. > > > > I have attached the data: > > The list software seems to have scrubbed it though... > > > The error message from Anova is: > > > >> pressure.aov = Anova(multmodel, idata=fact.idata, idesign = ~Shoe * > >> Region, type="III") > > Error in linearHypothesis.mlm(mod, hyp.matrix, SSPE = SSPE, idata = idata, > > : > > The error SSP matrix is apparently of deficient rank = 9 < 14 > > Oho. Yes that can be a problem. I it is not actually required to have a full > rank SSP to do the F tests, but the design of Anova() is such that it tries > to do multivariate analyses somewhere along the way, and I don't think > there's a way to tell it not to (John?). >
Yes, that's right: Anova() starts with the multivariate repeated-measures analysis and derives the univariate tests from that. When I have a chance, I'll take a look to see whether I can change that, reporting the error only when the MANOVA is requested. Best, John > I don't think plain anova.mlm has this particular restriction. It's basically > the same issue as this: > > > X <- matrix(rnorm(12),3,4) > > idata <- data.frame(gg = factor(1:4)) > > anova(m,idata=idata, X=~1, test="Spherical") > Analysis of Variance Table > > > Contrasts orthogonal to > ~1 > > Greenhouse-Geisser epsilon: 0.4312 > Huynh-Feldt epsilon: 0.8876 > > Df F num Df den Df Pr(>F) G-G Pr H-F Pr > (Intercept) 1 0.3376 3 6 0.79935 0.66045 0.77968 > Residuals 2 > > Anova(m,idata=idata, idesign=~gg, type="III") > Error in linearHypothesis.mlm(mod, hyp.matrix, SSPE = SSPE, idata = idata, : > The error SSP matrix is apparently of deficient rank = 2 < 3 > > anova(m,idata=idata, X=~1) # Full MV test fails here too > Error in anova.mlm(m, idata = idata, X = ~1) : residuals have rank 2 < 3 > > > -- > Peter Dalgaard, Professor > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Email: pd....@cbs.dk Priv: pda...@gmail.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.
