On Sat, 29 Nov 2003 [EMAIL PROTECTED] wrote: > Hi all, > > I'd like to extract a value from an ANOVA table, but experience the following > problem: > > ### This works: > > > s.pseudo <- summary(aov(m ~ block + mix*graz,data=split1)) > > s.pseudo > Df Sum Sq Mean Sq F value Pr(>F) > block 2 1114.66 557.33 4.4296 0.04192 * > mix 1 6.14 6.14 0.0488 0.82956 > graz 2 1.45 0.72 0.0057 0.99427 > mix:graz 2 3.82 1.91 0.0152 0.98495 > Residuals 10 1258.19 125.82 > --- > Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 > > s.pseudo[[1]]["mix ","Pr(>F)"] > [1] 0.8295556 > > ### But this doesn't -- why?
Why should it? > > s.split <- summary(aov(m ~ block + mix*graz + Error(Plot),data=split1)) > > s.split > > Error: Plot > Df Sum Sq Mean Sq F value Pr(>F) > block 2 1114.66 557.33 0.8994 0.5265 > mix 1 6.14 6.14 0.0099 0.9298 > Residuals 2 1239.37 619.68 > > Error: Within > Df Sum Sq Mean Sq F value Pr(>F) > graz 2 1.4464 0.7232 0.3073 0.7437 > mix:graz 2 3.8206 1.9103 0.8117 0.4776 > Residuals 8 18.8278 2.3535 > > s.split[["Error: Plot"]] ## extracting first list element works > Df Sum Sq Mean Sq F value Pr(>F) > block 2 1114.66 557.33 0.8994 0.5265 > mix 1 6.14 6.14 0.0099 0.9298 > Residuals 2 1239.37 619.68 > > s.split[["Error: Plot"]]["mix ","Pr(>F)"] ### <== FAILS > Error in s.split[["Error: Plot"]]["mix ", "Pr(>F)"] : > incorrect number of dimensions You should have written s.split[["Error: Plot"]][[1]]["mix ","Pr(>F)"] > So where is the difference between the two? One is an "aov" object, the other an "aovlist" object. Take a closer look at print.summary.aov, for example. More generally, learn how to look at R objects instead of assuming you know what you are doing: unclass(s.split[["Error: Plot"]]) would have been informative. -- 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 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help