[R] lme4 question
larry at hanser.net
Wed Oct 22 23:57:03 CEST 2008
Re Doug's comment:
I apologize for being incomplete--I do know better.
I did explicitly include a data statement in the models, but didn't
write the model statements properly in my post. Here are the actual
mod1 <- lmer(y ~ category + subcomp + (1 | id), data=prepchiefs08rm)
mod2 <- lmer(y ~ category + subcomp + category*subcomp + (1 | id),
On Wed, Oct 22, 2008 at 2:41 PM, Douglas Bates <bates at stat.wisc.edu> wrote:
> On Wed, Oct 22, 2008 at 4:18 PM, Lawrence Hanser <larry at hanser.net> wrote:
>> Dear R Colleagues,
>> I run the following two models:
>> mod1 <- lmer(y ~ category + subcomp + (1 | id))
>> mod2 <- lmer(y ~ category + subcomp + category*subcomp + (1 | id)
>> category has 4 possible values
>> subcomp has 24 possible values
>> id has approx 120 values (id is nested within category, and in unequal
>> numbers--i.e., unbalanced)
>> Then to look for differences in the models I run:
>> anova(mod1, mod2)
>> I receive this warning message after the last command:
>> In data != data[] :
>> longer object length is not a multiple of shorter object length
> That piece of code is comparing the values of the data arguments in
> the call slot of the fitted models. These are what are known as
> matched calls (produced by the function match.call). The second model
> you show seems incomplete. Did you miss a closing parenthesis or did
> you have an explicit data argument?
> I always use an explicit data argument and I probably implicitly
> thought that others would do that when I wrote the piece of code in
> question. I suppose I could remove that check or replace it with a
> better one. The purpose of the code is to determine if it is
> reasonable to compare the model fits by checking if the models were
> fit to the same data.
>> I think I know why this is happening (i.e., the two models are of
>> different length). Is my surmise correct? If I am correct I don't
>> think I should worry. Should I?
>> R-help at r-project.org mailing list
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> R-help at r-project.org mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
More information about the R-help