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 model statements: mod1 <- lmer(y ~ category + subcomp + (1 | id), data=prepchiefs08rm) mod2 <- lmer(y ~ category + subcomp + category*subcomp + (1 | id), data=prepchiefs08rm) Thanks. On Wed, Oct 22, 2008 at 2:41 PM, Douglas Bates <[EMAIL PROTECTED]> wrote: > On Wed, Oct 22, 2008 at 4:18 PM, Lawrence Hanser <[EMAIL PROTECTED]> 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) >> >> where: >> 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[[1]] : >> 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? >> >> Thanks. >> >> ______________________________________________ >> R-help@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. >> > > ______________________________________________ > R-help@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. > ______________________________________________ R-help@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.
