Comparing self-subsetting models

I was wondering if pymer4 has a way to compare two models varying in the presence/absence of a given variable in the formula. In R, this can be easily done with the command anova(). E.g.:

model1 <- lmer(DV + IV1 + (IV1 | Group), data=data)
model2 <- lmer(DV + IV1*IV2 + (IV1 + IV2 | Group), data=data)

anova(model1, model2)

The command Lmer.anova() in pymer4 does not seem to do the same, though. Is there a way to accomplish this?

P.S.: I am aware this is not a “bug” properly said, but opening a bug issue on Githus seems to be the only way to get in touch with the developers to ask this. Thanks!

[dramanica]

@ejolly Actually, I had a bit of spare time, so tests are now fully implemented. Whilst I was at it, I also added a wrapper to confint for the Lmer class, so that it is now possible to bootstrap and profile the variances of the random components. It’s an additional feature that I will need to use pymer4 in a course I plan to teach next year.

[ejolly]

Unfortunately not at this time. It’s on the short term todo list, so some time this year given my work commitments: https://trello.com/c/XOxtVjX0

I had started this functionality with the hope to compute it in pure Python rather than relying on R calls to keep things a bit speedy as can be seen in this commented code on the master branch: https://github.com/ejolly/pymer4/blob/master/pymer4/stats.py#L552

And this utility function: https://github.com/ejolly/pymer4/blob/master/pymer4/utils.py#L460

If memory serves, I wasn’t quite getting matching results with R and I’m sure some of the stats are probably being computed incorrectly and may end up requiring an R call.

Always happy to receive code contributions as PRs!