Hi, I am sorry to post the message again but I really need some advise on that. I am using the R version 2.11.0 and the version of sem package: sem_0.9-20 under Windows XP. I read the questions: http://r.789695.n4.nabble.com/computationally-singular-and-lack-of-variance-parameters-in-SEM-td891081.html#a891082
and http://r.789695.n4.nabble.com/computationally-singular-and-lack-of-variance-parameters-in-SEM-td891081.html#a891081 but it does not seem to be my problem. I try to replicate the sem model (see the attacheted image) but i got stuck with the problem while computing the estimates of the model: The error message: Error in nlm(if (analytic.gradient) objective.2 else objective.1, start, : probable coding error in analytic gradient In addition: Warning message: In sem.default(ram = ram, S = S, N = N, param.names = pars, var.names = vars, : The following variables have no variance or error-variance parameter (double-headed arrow): Fugural1 The model is almost surely misspecified; check also for missing covariances. Here is my script: cov.matrix <- matrix(c(56.21,0,0,0,0,0,0,0,0,31.55,75.55,0,0,0,0,0,0,0,23.27,28.30,44.45,0,0,0,0,0,0,24.48,32.24,22.56,84.64,0,0,0,0,0,22.51,29.54,20.61,57.61,78.93,0,0,0,0,22.65,27.56,15.33,53.57,49.27,73.76,0,0,0,33.24,46.49,31.44,67.81,54.76,54.58,141.77,0,0,32.56,40.37,25.58,55.82,55.33,47.74,98.62,117.33,0,30.32,40.44,27.69,54.78,53.44,59.52,96.95,84.87,106.35),nrow=9,ncol=9,byrow=FALSE) rownames(cov.matrix) <- colnames(cov.matrix) <- c("IND1","IND2","IND3","FR11","FR12","FR13","FR21","FR22","FR23") # options(nlm=(check.analyticals = TRUE)); I tried to set the nlm on different option, but did not work either m1 <- specify.model() Induction -> IND1, NA, 1 Induction -> IND2, y2, NA Induction -> IND3, y3, NA Fugural1 -> FR11, NA, 1 Figural1 -> FR12, y5, NA Figural1 -> FR13, y6, NA Figural2 -> FR21, NA, 1 Figural2 -> FR22, y8, NA Figural2 -> FR23, y9, NA Induction -> Figural1, x1, NA Figural1 -> Figural2,x2, NA Induction -> Figural2, x3, NA IND1 <-> IND1, e1, NA IND2 <-> IND2, e2, NA IND3 <-> IND3, e3, NA FR11 <-> FR11, e4, NA FR12 <-> FR12, e5, NA FR13 <-> FR13, e6, NA FR21 <-> FR21,e7, NA FR22 <-> FR22, e8, NA FR23 <-> FR23, e9, NA Figural1 <-> Figural1, e10, NA Figural2 <-> Figural2, e11, NA Induction <-> Induction, NA, 1 sem1 <- sem(m1,cov.matrix,N=220,debug=T) # I added the Induction <-> Induction, NA, 1 fixed parametr after reading the help from John Fox, that every variable should have an error variance Can anybody please advise me what I am doing wrong? Many thanks! Jan Schubert Institute of Social Science Charles University, Prague -- View this message in context: http://r.789695.n4.nabble.com/sem-error-no-variance-or-error-variance-parameter-tp2221804p2221804.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.
