nested and non-nested random effects
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On 11-03-15 04:37 PM, Iker Vaquero Alba wrote:
Hello: I have a doubt about the syntax for random effects, and I hope you can help me with that. I am fitting a mixed effects model with 3 random factors, let's call them A, B and C for simplicity. A and B are nested factors, B is nested into A, and C is not nested, it's just another random effect independent from the other 2. I guess the correct way to specify this in "lmer" would be something like: model1<-lmer(y~fixed1*fixed2+(1|A/B)+(1|C)) but I am not sure how I could do this with "lme". Maybe: model1<-lme(y~fixed1*fixed2,random=~1|A/B,random=~1/C) ??? or perhaps: model1<-lme(y~fixed1*fixed2,random=~C|A/B) ???
Fitting non-nested (i.e. crossed) random effects can be done in lme, but not easily: the best advice is to go read section 4.2.2 of Pinheiro and Bates 2000, esp. pp. 163-166. Why do you need to use nlme::lme rather than lme4::lmer ? (R-side random effects, p-values, .... ?) Ben Bolker -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk1/3EIACgkQc5UpGjwzenMbIwCfT6oSy43whFrpWNBat+8IUH1N JjEAn1y2HueNyt9ZZBspOAT6QtXya5RG =0cH4 -----END PGP SIGNATURE-----