Hello all,
I have an issue where I am generating data and trying to confirm the
estimates using a sem.  I keep getting an error about the degree of freedom
being negative "Error in sem.default(ram, S = S, N = N, raw = raw, data =
data, pattern.number = pattern.number,  : The model has negative degrees of
freedom = -6"

Can someone explain this error or tell me what is wrong with my model?
Thank you.
Here is the code:




model.ram1 <- specifyModel()
UNIT -> Y1, ty,0.3
UNIT -> Z1, tz1,-0.1
UNIT -> Z2, tz2,0.1
CF -> Y1, lamy,0.5
CF -> Z1, lamz1,0.85
CF -> Z2, lamz2,0.2
UNIT -> CF, k
Y1 <-> Y1, psi3, NA
Z1 <-> Z1, psi1, NA
Z2 <-> Z2, psi2, NA
CF <-> CF,vCF1,NA

sem.m1<-sem(model=model.ram1,S=S2,N=500,fixed.x="UNIT",raw=T)

-- 

I.J. Williams

Ph.D. Student in Education Measurement and Statistics
Statistics MS

Mathematics BS

Rutgers University

	[[alternative HTML version deleted]]

