[R] R SEM package

[John Fox]

Dear Anthony,

As I said, the sem package won't do multiple-group analysis. I would like at
some point to add multiple-group analysis to the capabilities of the package
but I can't say when I might find time to do that.

Sorry,
 John

------------------------------
John Fox, Professor
Department of Sociology
McMaster University
Hamilton, Ontario, Canada
web: socserv.mcmaster.ca/jfox


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
> Behalf Of Anthony Dick
> Sent: January-06-09 3:57 PM
> Cc: r-help at r-project.org
> Subject: Re: [R] R SEM package
> 
> Hi John-
> 
> Thanks for responding so quickly. Love the package by the way.
> 
> I am using R sem to model fMRI data, and I want to compare models
> between conditions (i.e., to see if there is a significant difference
> between specific path coefficients of two models). I believe this
> amounts to what is commonly referred to as a multi-group analysis, where
> two models are run simultaneously, allowing some coefficients to vary
> while others are maintained. The procedure is described briefly in the
> Appendix of: Pugesek & Tomer (1996). Evolutionary Ecology, 10, 387-404.
> 
> I am not sure if anova() does what I want it to.
> 
> Anthony
> 
> John Fox wrote:
> > Dear Anthony,
> >
> > I'm not sure what you mean by a "stacked model comparison." If you mean
a
> > model fit to multiple groups, then the answer is no. If you mean
comparison
> > of nested models, then anova() can be used to get a LR test. See
> ?anova.sem.
> >
> > I hope this helps,
> >  John
> >
> > ------------------------------
> > John Fox, Professor
> > Department of Sociology
> > McMaster University
> > Hamilton, Ontario, Canada
> > web: socserv.mcmaster.ca/jfox
> >
> >
> >
> >> -----Original Message-----
> >> From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]
> >>
> > On
> >
> >> Behalf Of Anthony Dick
> >> Sent: January-06-09 2:56 PM
> >> To: r-help at r-project.org
> >> Subject: [R] R SEM package
> >>
> >> Does anyone know if the sem package in R can implement a stacked model
> >> comparison, for example as in LISREL or AMOS?
> >>
> >> Thanks,
> >>
> >> Anthony
> >>
> >> --
> >> Anthony Steven Dick, Ph.D.
> >> Post-Doctoral Fellow
> >> Human Neuroscience Laboratory
> >> Department of Neurology
> >> The University of Chicago
> >> 5841 S. Maryland Ave. MC-2030
> >> Chicago, IL 60637
> >> Phone: (773)-834-7770
> >> Email: adick at uchicago.edu
> >> Web: http://home.uchicago.edu/~adick/
> >>
> >> ______________________________________________
> >> R-help at 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.
> >>
> >
> >
> >
> 
> 
> --
> Anthony Steven Dick, Ph.D.
> Post-Doctoral Fellow
> Human Neuroscience Laboratory
> Department of Neurology
> The University of Chicago
> 5841 S. Maryland Ave. MC-2030
> Chicago, IL 60637
> Phone: (773)-834-7770
> Email: adick at uchicago.edu
> Web: http://home.uchicago.edu/~adick/
> 
> ______________________________________________
> R-help at 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.