Dear Anthony,
>From ?sem:
"If given as NA, the program will compute a start value, by a slight
modification of the method described by McDonald and Hartmann (1992). Note:
In some circumstances, some start values are selected randomly; this might
produce small differences in the parameter estimates when the program is
rerun."
To see exactly what's done, print out the startvalues function.
Regards,
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-25-09 9:15 PM
> To: r-help at r-project.org
> Subject: [R] sem package: start values
>
> Hello-
>
> If I input a variance-covariance matrix and specify NA for start values,
> how does sem determine the start value? Is there a default?
>
> 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/
>
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