[R-sig-ME] contrasts for generalized linear model
robert.espesser at lpl-aix.fr
Wed May 25 18:16:00 CEST 2011
If I understand well your data, year (in fact, TSB) is the (main ?)
fixed effect, and is not a random term.
I suppose there are levels enough for pop.
I think your model would be something like :
lmer(flowering ~ TSB +(1|pop) ,family=binomial, data=....)
I would use successive difference contrast for the 3 levels factor TSB.
see contr.sdif() in library(MASS).
Le 25/05/2011 17:15, Wade Wall a écrit :
> Hi all,
> This question has perhaps been answered before, but I can't find a reference
> to it. I have a data set that consists of binomial data (plant flowering)
> and time since the plant was last burned (1, 2, or 3 years ago). There
> appears to be a main effect ( flowering is reduced in year 1), but I want to
> compare years 2 and 3 to see if flowering is decreasing by year three. The
> model that I included random effects of Year (year data collected) and
> population (multiple pops).
> The data set basically looks like this:
> Pop Year TSB Flowering
> 1 2008 1 1
> 1 2008 1 0
> . . . . .
> 24 2010 3 0
> 24 2010 3 1
> What is the best way to set up contrasts for binomial data in R? Is it
> basically the same as with an ANOVA?
> Thanks for any information.
> [[alternative HTML version deleted]]
> R-sig-mixed-models at r-project.org mailing list
CNRS UMR 6057 - Université de Provence
5 Avenue Pasteur
Tel: +33 (0)442 95 36 26
More information about the R-sig-mixed-models