On May 5, 2011, at 23:30 , Rovinpiper wrote: > Thanks slre, > > I seem to be making some progress now. > > Using a colon instead of an asterisk in the code really changes things. I > had been getting residual SS and MS of zero. Which is ridiculous. Now I get > much more plausible values. > > Also, When I used an asterisk instead of a colon It wouldn't give results > for three way interactions. With colons it will. > > You are correct about plot being nested within treatment. There are six > plots in each of 2 treatments. > > So, I guess I will have to perform a separate analysis to quantify the > effect of treatment. >
Beware that as you have highly significant effects of plot and its interaction with day, and plot being nested in treatment, you can't test for treatment or treatment:day effect with a systematic effect of plot and plot:treatment in the model (you are only getting p values because of the sequential computation of the anova table - if you put plot before treatment, you'd get zero df). More likely, you want to make the "plot" terms random, as in ~treatment*day + Error(plot/day) > Thanks again. > > Analysis of Variance Table > > Response: Combined.Rs > > Df Sum Sq Mean Sq F value Pr(>F) > Combined.Trt 1 > 52.80 52.805 96.2601 < 2.2e-16 *** > Combined.Plot 10 > 677.69 67.769 123.5380 < 2.2e-16 *** > as.factor(Combined.Day) 16 > 2817.47 176.092 321.0041 < 2.2e-16 *** > Combined.Trt:as.factor(Combined.Day) 16 47.82 > 2.989 5.4487 4.048e-10 *** > Combined.Trt:Combined.Plot:as.factor(Combined.Day)80 455.42 5.693 > 10.3776 < 2.2e-16 *** > Residuals > 284 155.79 0.549 > --- > Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > > > -- > View this message in context: > http://r.789695.n4.nabble.com/ANOVA-1-too-few-degrees-of-freedom-tp3493349p3499649.html > Sent from the R help mailing list archive at Nabble.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. -- Peter Dalgaard 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.