Here P is already nested in Q, so s:P suffices. You are getting the warning because most of the cells of s:P:Q are empty.
On Tue, 14 Mar 2006, John Vokey wrote: > The following dummy data frame has factor Q (with 2 levels) nesting > factor P (with levels p1 and p2 nested under q1, and p3 and p4 nested > under q2), but both crossing the random variate s, which has 8 > levels. The dependent measure is dv. > > # The data frame: > > testnest > dv s P Q > 1 1 s1 p1 q1 > 2 2 s2 p1 q1 > 3 1 s3 p1 q1 > 4 2 s4 p1 q1 > 5 1 s5 p1 q1 > 6 3 s6 p1 q1 > 7 3 s7 p1 q1 > 8 4 s8 p1 q1 > 9 2 s1 p2 q1 > 10 3 s2 p2 q1 > 11 3 s3 p2 q1 > 12 1 s4 p2 q1 > 13 1 s5 p2 q1 > 14 2 s6 p2 q1 > 15 2 s7 p2 q1 > 16 3 s8 p2 q1 > 17 3 s1 p3 q2 > 18 3 s2 p3 q2 > 19 4 s3 p3 q2 > 20 1 s4 p3 q2 > 21 1 s5 p3 q2 > 22 1 s6 p3 q2 > 23 2 s7 p3 q2 > 24 2 s8 p3 q2 > 25 4 s1 p4 q2 > 26 3 s2 p4 q2 > 27 1 s3 p4 q2 > 28 2 s4 p4 q2 > 29 4 s5 p4 q2 > 30 1 s6 p4 q2 > 31 3 s7 p4 q2 > 32 1 s8 p4 q2 > > # The following aov() call is structurally correct with respect > # to the design, and appropriate error-terms, but, as can be seen, > # returns an error: > > > testnest.aov=aov(dv~Q+P%in%Q+Error(s+s:Q+s:P:Q),data=testnest) > Warning message: > Error() model is singular in: aov(dv ~ Q + P %in% Q + Error(s + s:Q + > s:P:Q), data = testnest) > > # However, applying the summary() method to the aov output, produces > the correct analysis: > > > summary(testnest.aov) > > Error: s > Df Sum Sq Mean Sq F value Pr(>F) > Residuals 7 5.8750 0.8393 > > Error: s:Q > Df Sum Sq Mean Sq F value Pr(>F) > Q 1 0.1250 0.1250 0.068 0.8018 > Residuals 7 12.8750 1.8393 > > Error: s:Q:P > Df Sum Sq Mean Sq F value Pr(>F) > Q:P 2 0.250 0.125 0.1111 0.8956 > Residuals 14 15.750 1.125 > > I have tried many different ways of denoting the Error() > partitioning, but can't find one that produces both the correct > analysis *AND* no singularity error on the aov() call. Any suggestions? > > -- > Please avoid sending me Word or PowerPoint attachments. > See <http://www.gnu.org/philosophy/no-word-attachments.html> > > -Dr. John R. Vokey > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html