[R-sig-ME] Binary variables used with lme model

[ONKELINX, Thierry]

Hi Igor,

If your response is binary, you must treat it as binary. Lme only works
with continuous data. Use glmer() from the lme4 package instead.

HTH,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen
Belgium

Research Institute for Nature and Forest
team Biometrics & 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-sig-mixed-models-bounces at r-project.org 
> [mailto:r-sig-mixed-models-bounces at r-project.org] Namens Igor Blanco
> Verzonden: woensdag 21 juli 2010 18:23
> Aan: r-sig-mixed-models at r-project.org
> Onderwerp: [R-sig-ME] Binary variables used with lme model
> 
> Hi there,
> 
> I am trying to analyze some data using the lme package.
> My data contains continuous variables but there is one 
> specific variable called Newmarker that can only take 2 
> values (number 1 or number 2).
> I am interested in using this as a "flag" when I apply a lme 
> model I have used the as.factor trying to remark this fact 
> but an error message appears stating: attempt to set rownames 
> on object with no dimensions.
> 
> Here is the code I have used:
> 
> *Dataset <-   read.table("Data2.txt", header=TRUE, sep="", 
> na.strings="NA",
> dec=".", strip.white=TRUE)
> 
> Dataset$Newmarker <- as.factor(Dataset$Newmarker)
> 
> lme.1 <- lme(Newmarker ~ Age, data=Dataset,  random= ~1|ID)
> 
> summary(lme.1)*
> 
> If I don't use the as.factor I have no problems but the 
> results don't reflect the fact of my "binary" variable Newmarker..
> 
> Can anybody help me please?
> 
> Thanking you in advance,
> 
> Much appreciated,
> 
> Igor Blanco
> 
> 	[[alternative HTML version deleted]]
> 
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> 

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