[R-sig-eco] ci's for fixed effects in lme

[Philip Dixon]

  Manuel,

The problem is that tempo is declared as both a fixed effect and a 
random effect in modelo2.  If tempo were a factor, that would be a 
disaster because the same effect (differences among groups) would be 
modeled two ways simultaneously.

In your model, tempo (fixed effect) defines a regression while tempo 
(random effect) defines deviations of tempo group means from that 
regression.  That should not be a problem (I say should only because I 
haven't checked that this model is correctly fit by lme).

The solution is to create a copy of tempo and use one variable to define 
the fixed effect and the second to define the random effect:

ipa$tempog <- ipa$tempo
modelo2 = lme(ipa ~ tempo, random = ~1 | tempog/localidad, data=ipa)

Best wishes,
Philip Dixon