From: Douglas Bates <dmbates_at_gmail.com>

Date: Sat 28 Jan 2006 - 10:52:45 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Jan 28 10:59:46 2006

Date: Sat 28 Jan 2006 - 10:52:45 EST

On 27 Jan 2006 23:08:28 +0100, Peter Dalgaard <p.dalgaard@biostat.ku.dk> wrote:

> Søren Højsgaard <Soren.Hojsgaard@agrsci.dk> writes:

*>
**> > Along similar lines, I've noticed that the anova() function for lmer
**> > models now only reports the mean squares to go into the numerator
**> > but "nothing for the denominator" of an F-statistic; probably in
**> > recognition of the degree of freedom problem. It could be nice,
**> > however, if anova() produced even an approximate anova table which
**> > can be obtained from Wald tests. The anova function could then print
**> > that "these p-values are large sample ones and hence only
**> > approximate"...
**>
**> I'm reasonably convinced by now that the relevant denominator is
**> always the residual variance, but it is happening via deep magic that
**> I don't quite understand... (and is quite counterintuitive to people
**> who are used to the traditional ANOVA decompositions in orthogonal
**> designs)
*

Not deep magic for you, Peter. The slot called rXy in the fitted model is analogous to the first p components of the "effects" component in an lm model. Cut it up according to the terms and sum the squares.

> While we're on the subject: It would be desirable to have Wald tests

*> for specific terms rather than the "Type 1" (sorry, Bill) progressive
**> ANOVA table. Just like we already have in lme().
*

I think this is the point where I mention the Open Source nature of project. Sorry to say that it is not a priority for me right now.

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Jan 28 10:59:46 2006

*
This archive was generated by hypermail 2.1.8
: Fri 03 Mar 2006 - 03:42:14 EST
*