R help - Apr 2009 - qqnorm.lme & pairs.lme

Hello,

I am trying to do some plotting to check random effect assumptions for a
model I fit using lme.

I want to use qqnorm and pairs (similarly to examples given in Pinheiro &
Bates p. 188), but it's not working.  Here's some relevant code and the
error message:

library(nlme)
data(Machines)
m1 <- lme(fixed=score~Machine,random=~1|Worker/Machine, data=Machines)
qqnorm(m1, ~ranef(.))

Error in rep(names(fData), rep(nr, nc)) : invalid 'times' argument
In addition: Warning message:
In data.frame(Worker = list("(Intercept)" = c(-7.51429457896346,  :
  row names were found from a short variable and have been discarded

I also tried changing the last line to qqnorm(m1, form=~ranef(.))

Any advice?

Thanks,
Pat Zimmerman

	[[alternative HTML version deleted]]

The model has multiple levels of random effects, so you need to tell
qqnorm.lme which one you're interested in.

e.g.

qqnorm(m1, ~ranef(., level=1))



hth,
Kingsford Jones



On Thu, Apr 23, 2009 at 11:03 AM, Patrick Zimmerman <patzimm at gmail.com>
wrote:
> Hello,
>
> I am trying to do some plotting to check random effect assumptions for a
> model I fit using lme.
>
> I want to use qqnorm and pairs (similarly to examples given in Pinheiro
&
> Bates p. 188), but it's not working. ?Here's some relevant code and
the
> error message:
>
> library(nlme)
> data(Machines)
> m1 <- lme(fixed=score~Machine,random=~1|Worker/Machine, data=Machines)
> qqnorm(m1, ~ranef(.))
>
> Error in rep(names(fData), rep(nr, nc)) : invalid 'times' argument
> In addition: Warning message:
> In data.frame(Worker = list("(Intercept)" = c(-7.51429457896346,
?:
> ?row names were found from a short variable and have been discarded
>
> I also tried changing the last line to qqnorm(m1, form=~ranef(.))
>
> Any advice?
>
> Thanks,
> Pat Zimmerman
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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