Hi all,

I am looking for some clarification in the syntax of the random effects
found in a mixed model written in 'lme'.  I have determined that I need
both random intercepts (longitudinal data) and random slopes (investigation
of lattice plots and preliminary model fitting) for a model I'm working
on.  However, where I am unclear is whether to write the fixed effects as:

Option A:  random=~MeanUrban|Male

Option B:  random=~1+MeanUrban|Male

Option C:  random=list(~1|Male, ~0+MeanUrban|Male)

Option D:  random=list(~1|Male, ~MeanUrban-1|Male)

I know this has to do with correlated random effects and part of that
decision is made by visual inspection of the raw data, but part of it has
to be based on some sort of quantitative conclusion based on the results of
the models.  Please advise of how to proceed.  Thank you for your time.

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