On Mon, Aug 9, 2010 at 9:29 AM, David Winsemius <dwinsem...@comcast.net> wrote: > If you look at the output (as I did) you should see that despite whatever > expectations you have developed regarding plyr, that it did not produce a > grouping variable: > >> ldply(dl, function(x) coef(summary(x)) ) > fac Estimate Std. Error t value Pr(>|t|) > 1 0 -0.3563418 0.1438322 -2.477483 1.820555e-02 > 2 1 0.9197772 0.1525900 6.027768 7.097623e-07 > 3 2 3.0481679 0.1331307 22.896050 1.197920e-22 > 4 0 -18.7726473 0.1281064 -146.539553 2.125848e-50 > 5 1 -0.2961841 0.1885210 -1.571093 1.273942e-01 > 6 2 1.2846496 0.1833394 7.006946 1.277086e-07 > 7 0 2.9664816 0.1737222 17.076010 2.448612e-16 > 8 1 -18.7265068 0.2044723 -91.584567 3.048491e-36 > 9 2 0.3993073 0.1979713 2.016996 5.455569e-02 > 10 0 0.7657945 0.2477459 3.091048 4.846678e-03 > 11 1 3.0365005 0.1731814 17.533641 1.470033e-15 > 12 2 -19.2140081 0.1882448 -102.069256 2.741417e-34
cf. > ldply(dl, coef) fac (Intercept) x1 x2 x3 1 0 -0.12051346 1.1391933 3.022287 -19.01828 2 1 -0.08890497 1.0741715 3.219577 -19.14279 3 2 -0.12728421 0.9284263 2.973905 -19.12774 which you can see maintains the original grouping variable fac. The problem is that summary stores the variable names as rownames, which does not make for easy rbinding. Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ 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.