Dear R users,
     We have encountered a slight problem when using the lmer()
function:

  1. Data description: 11 locations; Nt: monthly mosquito population
density from 1994-2005 in each location. 
  2. Question: to examine the degree of spatial heterogeneity in the
system by testing model support for single versus multiple intercepts
and slopes for the location effect. We applied the lmer() function and
introduced location as spatial effect. Four different models were
generated as following: 
a.	1 intercept & 1 slope :  lmer(r~log(N)+(1|location)), where r <-
log(Nt/Nt-1) and location is a random effect.
b.	Multi-intercept & 1 slope: lmer(r~location+log(N)+(1|location))
c.	1 slope & multi-intercept: ??????
d.	Multi-intercept & multi-slope:
lmer(r~location*log(N)+(1|location))


As you can see, we have had trouble defining model c. Does anyone know
how to code this using lmer? We really appreciate any response.
Guojing   


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