From: Sunil W <sunnyw_at_hotmail.com>

Date: Thu 01 Dec 2005 - 14:07:44 EST

m1<->m1, v1,NA

m2<->m2, v2,NA

y<->y, v3,NA

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 Thu Dec 01 14:14:45 2005

Date: Thu 01 Dec 2005 - 14:07:44 EST

Hi

I am running a structural equation model with R using the sem command; am getting the following error:

"Error in sem.default : The model has negative degrees of freedom = -4"

My model is as follows:

s_model = specify.model()

x1->m1, b1,NA x2->m1, b2,NA x3->m2, b3,NA x4->m2, b4,NA x5->m2, b5,NA x6->m2, b6,NA m1->y, a1,NA m2->y, a2,NA

m1<->m1, v1,NA

m2<->m2, v2,NA

y<->y, v3,NA

x1-x6 are observed independent variables, m1 and m2 are the latent variables and y is the observed dependent variable. I use the raw.moments command for calculating the covariance matrix, based on a data with 147 observations.

The command that I use is as follows:

s = sem(s_model,S=R,obs.variables=colnames(R), fixed.x=c('x1','x2','x3','x4','x5','x6'), raw=TRUE)

I would appreciate any help on this; I am new to structural equation models and realize that I may be making a silly error.

Thanks

Sunil

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 Thu Dec 01 14:14:45 2005

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