R help - Nov 2005 - coding nesting in data for nlme example of Wafer data set.

I am trying to understand the proper way to encode the nesting structure
for data in the context of nlme, in the specific case of individuals
nested within species for which each individual is unique.  I have
searched through Pinheiro & Bates and also past postings, but without
success.

 

Take the Wafer data set which has 2 levels: Wafer (8 values) and Site
nested within Wafer (10 values for each value of Wafer)  (Pinheiro &
Bates book).  The data set has Sites coded as values from 1 to 8 for
Wafer 1, values 1 to 8 for Wafer 2 etc.  Does this mean that the SAME
sites are used for each Wafer (i.e. site 1 of water 1 is the same as
site 1 of wafer 2)?  If different sites were chosen for each of the
wafers would one have to code the sites = 1 to 8 for Wafer 1, sites = 9
to 16 for Wafer 2, and so on?

In the case of individuals nested within species, each individual is
unique - analogous to different sites being chosen for each wafter.  

 

Thanks.

 

Bill Shipley

 


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Doug Bates made an important comment that might help you with this. 
I found it via RSiteSearch("nesting in lmer"): 
"http://finzi.psych.upenn.edu/R/Rhelp02a/archive/47423.html".

	  If you still have questions after this, please submit another post, 
preferably illustrating your question with a self-contained example in a 
few lines of R code that illustrate the problem you are having (as 
suggested in the posting guide
"www.R-project.org/posting-guide.html").
  Doing so might increase your chances of getting a quick and useful 
reply.

	  spencer graves

Bill Shipley wrote:
> I am trying to understand the proper way to encode the nesting structure
> for data in the context of nlme, in the specific case of individuals
> nested within species for which each individual is unique.  I have
> searched through Pinheiro & Bates and also past postings, but without
> success.
> 
>  
> 
> Take the Wafer data set which has 2 levels: Wafer (8 values) and Site
> nested within Wafer (10 values for each value of Wafer)  (Pinheiro &
> Bates book).  The data set has Sites coded as values from 1 to 8 for
> Wafer 1, values 1 to 8 for Wafer 2 etc.  Does this mean that the SAME
> sites are used for each Wafer (i.e. site 1 of water 1 is the same as
> site 1 of wafer 2)?  If different sites were chosen for each of the
> wafers would one have to code the sites = 1 to 8 for Wafer 1, sites = 9
> to 16 for Wafer 2, and so on?
> 
> In the case of individuals nested within species, each individual is
> unique - analogous to different sites being chosen for each wafter.  
> 
>  
> 
> Thanks.
> 
>  
> 
> Bill Shipley
> 
>  
> 
> 
> 	[[alternative HTML version deleted]]
> 
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