R help - May 2009 - Help with lme4 model specification

I am new to R and am trying to specify a model for mixed model analysis. 
When I run the following model I get an error:

AAT<- lmer(Y ~ S + A + (1|S:A/H), data=AT, REML=True)

The error looks like this:

Error in Spar_loc:`:` : NA/NaN argument
In addition: Warning messages:
1: In model.matrix.default(mt, mf, contrasts) :
  variable 'Spar_loc' converted to a factor
2: In Spar_loc:`:` :
  numerical expression has 720 elements: only the first used

I am having trouble specifying th random component.  It should reflect the
random term as H nested within the interaction of S & A.  What am I doing
wrong?
:confused:
-- 
View this message in context:
http://www.nabble.com/Help-with-lme4-model-specification-tp23415908p23415908.html
Sent from the R help mailing list archive at Nabble.com.

Le mercredi 06 mai 2009 ? 15:21 -0700, boeinguy2 a ?crit
:
> I am new to R and am trying to specify a model for mixed model analysis. 
> When I run the following model I get an error:
> 
> AAT<- lmer(Y ~ S + A + (1|S:A/H), data=AT, REML=True)
> 
> The error looks like this:
> 
> Error in Spar_loc:`:` : NA/NaN argument
> In addition: Warning messages:
> 1: In model.matrix.default(mt, mf, contrasts) :
>   variable 'Spar_loc' converted to a factor
This is suspicious : Spar_loc doesn't appear in your statement...
> 2: In Spar_loc:`:` :
>   numerical expression has 720 elements: only the first used
Ditto...
> I am having trouble specifying th random component.  It should reflect the
> random term as H nested within the interaction of S & A.  What am I
doing
> wrong?
The precedence of modelling operators is not very clear (and does not
seem to be formally defined in the "standard" documentation...). In
doubt, use parentheses.

So try ...+(1|(S:A)/H), just in case...

You might also try to define it outside the model by adding variables :

AT<-within(AT,{SA=S:A, SAH=SA:H[,drop=TRUE]})
AAT<-lmer(y~S+A+(1|SAH),data=AT,REML=TRUE)
> :confused:
Enlightened ?

					Emmanuel Charpentier

Please note that the case of characters is important in R. Hence
"True"
differs from "TRUE". You need to use REML = TRUE instead of REML =
True!
The only valid logical values are TRUE, FALSE, T and F. But I recommend
to use only TRUE and FALSE. Because you can overwrite T and F. You could
do something like T <- FALSE, which is ofcourse not a good idea. TRUE
and FALSE can not be overwritten.

HTH,

Thierry


------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium 
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be 
www.inbo.be 

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
Namens boeinguy2
Verzonden: donderdag 7 mei 2009 0:21
Aan: r-help at r-project.org
Onderwerp: [R] Help with lme4 model specification


I am new to R and am trying to specify a model for mixed model analysis.

When I run the following model I get an error:

AAT<- lmer(Y ~ S + A + (1|S:A/H), data=AT, REML=True)

The error looks like this:

Error in Spar_loc:`:` : NA/NaN argument
In addition: Warning messages:
1: In model.matrix.default(mt, mf, contrasts) :
  variable 'Spar_loc' converted to a factor
2: In Spar_loc:`:` :
  numerical expression has 720 elements: only the first used

I am having trouble specifying th random component.  It should reflect
the
random term as H nested within the interaction of S & A.  What am I
doing
wrong?
:confused:
-- 
View this message in context:
http://www.nabble.com/Help-with-lme4-model-specification-tp23415908p2341
5908.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer 
en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is
door een geldig ondertekend document. The views expressed in  this message 
and any annex are purely those of the writer and may not be regarded as stating 
an official position of INBO, as long as the message is not confirmed by a duly 
signed document.