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?). 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.