[R] path analysis

[Manel Salamero]

This solves part of my problem with the independent ordinal variables, but my dependent variable is truly categorial (illness/no illness). Polychoric correlation implies that data are continuous, which in not the case. Is possible to implement logistic regression in the path model?

Thanks,

Manel Salamero

---------- Original Message ----------------------------------
De: "John Fox" <jfox at mcmaster.ca>
Data:  Sat, 13 Aug 2005 19:35:24 -0400

Dear Manel,

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of 
> SALAMERO BARO, MANUEL
> Sent: Saturday, August 13, 2005 2:02 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] path analysis
> 
> Someone knows if it is possible to perform a path analysis 
> with sem package (or any other) to explain a dependent 
> *dichotomus* variable?
> 

Yes -- you can use the hetcor() function in the polycor package to generate
a correlation matrix and boot.sem() in the sem package to get standard
errors or confidence intervals. Make sure that the dichotomous variables are
represented as factors. See ?boot.sem for an example.

I hope this helps,
 John