For nested, repeated measures of normally distributed data, the best
capability available in R (and perhaps anywhere) is in the 'nlme'
package. Excellent documentation is available in Pinheiro and Bates
(2000) Mixed-Effects Models in S and S-Plus (Springer). This book is
also a superlative research monograph by one of the leading contributors
in this area (Bates) and one of his former graduate students (Pinheiro).
If your data are not normal, you may want to use 'lmer' in the 'lme4'
and 'Matrix' packages; if you need that, please search the archives for
more information on that.
For help getting data into R, if you have R installed, "help.start()"
provides easy access to standard documentation shipped with R and
available without Internet access. See especially "R Data
Import/Export" and "An Introduction to R".
The simplest way I've found to get data into R is to first store it
something like "*.csv" or "*.txt" format, plain text with a unique "sep"
character that is only used to separate fields. Then I store the file
name (with the path if different from 'getwd()') in a variable like
'File'. Note that "\" is an escape character in R, and to get a
character interpreted as "\", you must use either "\" or "/".
Then I use "readLines" to check the format, including identifying the
"sep" character. Then I use "count.fields" to determine the number of
fields in each record and the number of records. If I don't get the
right answer there, I may not have the correct "sep" character. Or I
need to read the file in pieces, because of problems in the file.
Then I use "read.data". It has many arguments that can be used to
modify the "sep" character, skip lines at the beginning of the file and
then read only a certain number of lines, per the output from
"count.fields".
Hope this helps.
Spencer Graves
Doran, Harold wrote:
> You can read the manual, read the FAQs, search the help functions and the
> archives.
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] on behalf of Eric C Merten
> Sent: Fri 7/21/2006 8:51 PM
> To: [email protected]
> Subject: [R] nested repeated measures in R
>
> R help,
>
> How would I input data, verify assumptions, and run a nested repeated
> measures ANOVA using R? I have STATION nested in SITE nested in BLOCK with
> measurements repeated for five YEARs. All are random variables and it's only
> slightly unbalanced. I'm trying to characterize spatiotemporal variation in
> stream habitat variables. Thanks for your help!
>
> Eric Merten
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
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>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
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