Hi everyone, I'm using lmer and estimable (from packages lme4 and gmodels respectively) and have the disconcerting happening that when I run exactly the same code, I get different results! In checking this out by running the code 50x, it seems to be that answers may be randomly deviating around those which I get from another stats package (GenStat, using the linear mixed models functionality in this). As such, my guess is that perhaps there is a random seed involved somewhere in the estimable function, and that the answer is simply converging to a slightly different place each time, based on a slightly different starting place. But this is only a guess - if anyone could either confirm or otherwise explain this unexpected-to-me happening, that'd be fantastic!!
The code that I'm running is: design.1 = rbind(c(0,0,0,1,0,0,0,0,0,0,0,0)) lme1 <- lmer(var_x~AGE*GENDER*DAM_DIET + (1|CHIP) + (1|LITTER),x_temp) est <- estimable(lme1,design.1) print(est) est <- estimable(lme1,design.1) # Repeat of code print(est) est <- estimable(lme1,design.1) # Another repeat of code print(est) And this is the output - you can see in this that the results vary each time the code is run... > print(est) Estimate Std. Error p value (0 0 0 1 0 0 0 0 0 0 0 0) 0.02241752 0.2185279 0.902 > est <- estimable(lme1,design.1) > print(est) Estimate Std. Error p value (0 0 0 1 0 0 0 0 0 0 0 0) 0.001824573 0.2106973 0.974 > est <- estimable(lme1,design.1) > print(est) Estimate Std. Error p value (0 0 0 1 0 0 0 0 0 0 0 0) 0.01276941 0.2154196 0.938 My SessionInfo is as follows: R version 2.9.2 (2009-08-24) i386-pc-mingw32 locale: LC_COLLATE=English_New Zealand.1252;LC_CTYPE=English_New Zealand.1252;LC_MONETARY=English_New Zealand.1252;LC_NUMERIC=C;LC_TIME=English_New Zealand.1252 attached base packages: [1] splines stats graphics grDevices utils datasets tcltk methods base other attached packages: [1] lme4_0.999375-32 Matrix_0.999375-31 lattice_0.17-25 multcomp_1.1-2 survival_2.35-7 mvtnorm_0.9-7 gmodels_2.15.0 svIDE_0.9-5 loaded via a namespace (and not attached): [1] gdata_2.4.2 grid_2.9.2 gtools_2.6.1 MASS_7.2-48 svMisc_0.9-5 Many thanks for any help or advice that anyone can provide :) Cheers, Zaneta ____________________________ Zaneta Park Biometrician T +64 6 351 8008 E zaneta.park...@agresearch.co.nz AgResearch Limited Grasslands Research Centre Tennent Drive, Private Bag 11008, Palmerston North, New Zealand T +64 6 356 8019 F +64 6 351 8032 www.agresearch.co.nz Farming Food and Health. First Te Ahuwhenua Te Kai me te Whai Ora. Tuatahi ======================================================================= Attention: The information contained in this message and...{{dropped:15}} ______________________________________________ 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.