[R-sig-ME] What is the lmer/nlme equivalent of the REPEATED subcommand in SPSS's MIXED procedure?

[Phillip Alday]

Perhaps somebody with a better understanding of the covariance structure
in lme4 can comment, but I thought that lmer used an unstructured
covariance structure.  This seems to be one of the "bigger" nlme
features missing from lme4 -- there's no way to specify a structured
covariance such as AR1, etc.

(If I'm wrong, I would love to be corrected as it will only help my own
understanding of these things!)

Phillip



On 20/03/18 17:30, Maarten Jung wrote:
> Dear Ben, dear Phillip,
> 
> comparing [1] with [2] I think the /REPEATED command specifies the error
> (co)variance structure of the model. Would you agree with that?
> If so, AFAIK this is not possible with lmer and thus the answer on Stack
> Overflow [3] would be wrong.
> 
> [1] https://stats.idre.ucla.edu/r/examples/alda/r-applied-longitudinal-data-analysis-ch-7/
> [2] https://stats.idre.ucla.edu/spss/examples/alda/chapter7/applied-longitudinal-data-analysis-modeling-change-and-event-occurrenceby-judith-d-singer-and-john-b-willett-chapter-7-examining-the-multilevel-model-s-erro/
> [3]
> https://stackoverflow.com/questions/48518514/what-is-the-lmer-nlme-equivalent-of-the-repeated-subcommand-in-spsss-mixed-proc
> 
> Regards,
> Maarten
> 
> On Tue, Mar 20, 2018 at 2:10 PM, Ben Pelzer <b.pelzer at maw.ru.nl
> <mailto:b.pelzer at maw.ru.nl>> wrote:
> 
>     Dear Maarten,
> 
>     Take a look at
> 
>     https://stats.idre.ucla.edu/r/examples/alda/r-applied-longitudinal-data-analysis-ch-7/
>     <https://stats.idre.ucla.edu/r/examples/alda/r-applied-longitudinal-data-analysis-ch-7/>
> 
>     which shows you a number of covariance structures, among which is
>     the unstructured matrix, for repeated measures in R with lme. It
>     refers to chapter 7 of Singer and Willett where they discuss all
>     these different structures and how to choose among them. Regards,
> 
>     Ben.
> 
>     On 20-3-2018 9:00, Maarten Jung wrote:
> 
>         Dear list,
>         I came across a SPSS syntax like this
> 
>         MIXED value BY factor1
>              /CRITERIA=CIN(95) MXITER(100) MXSTEP(10) SCORING(1)
>         SINGULAR(0.000000000001)
>              HCONVERGE(0, ABSOLUTE) LCONVERGE(0, ABSOLUTE)
>         PCONVERGE(0.000001,
>              ABSOLUTE)
>              /FIXED=factor1 | SSTYPE(3)
>              /METHOD=REML
>              /REPEATED=factor1 | SUBJECT(participant) COVTYPE(UN).
> 
>         and struggle to find an equivalent lmer/nlme (or R in general)
>         formulation
>         for this kind of models.
>         Does anybody know how to convert the REPEATED subcommand into R
>         code?
> 
>         Please note that I asked the question on Stack Overflow about
>         two month ago:
>         https://stackoverflow.com/questions/48518514/what-is-the-lmer-nlme-equivalent-of-the-repeated-subcommand-in-spsss-mixed-proc
>         <https://stackoverflow.com/questions/48518514/what-is-the-lmer-nlme-equivalent-of-the-repeated-subcommand-in-spsss-mixed-proc>
> 
>         Best regards,
>         Maarten
> 
>                 [[alternative HTML version deleted]]
> 
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