Re: [R] sem error message

Hi, You did a really good job providing a reproducible example, except that you didn't mention which package sem() comes from. (sem, I'm assuming). I don't know how you came up with your covariance matrix, but it *isn't* symmetric: > isSymmetric(S.Seed.BB) [1] FALSE > S.Seed.BB[6, 2] [1] 37.758

[R] sem error message

Hello, I tried to do a 'sem' analysis for data of how blueberry consumption by birds is influenced by a pollution gradient, using distance and vegetation structural and composition variables, but I got the following error message: Error in sem.default(ram = ram, S = S, N = N, param.names = pars, v

Re: [R] SEM error

Dear Kesinee, > -Original Message- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of Kes > Sent: March-07-11 9:51 PM > To: r-help@r-project.org > Subject: [R] SEM error > > Dear All, > I am new for R and SEM. I try to fi

[R] SEM error

Dear All, I am new for R and SEM. I try to fit the model with Y (ordinal outcome), X (4 categorical data), M1-M3 (continuous), and 2 covariates (Age&sex) as a diagram. library(polycor) model.ly <-specify.model() 1: x -> m1, gam11, NA 2: x -> m2, gam12, NA 3: x -> m3, gam13, NA 4: age -> m1, gam1

Re: [R] sem error "no variance or error-variance parameter"

Hi, many thanks for the help (i would swear I controlled the model specification like 15 times...). It runs correctly now! Best wishes, 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

Re: [R] sem error "no variance or error-variance parameter"

> -Original Message- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Jan Schubert > Sent: Tuesday, May 18, 2010 12:51 PM > To: r-help@r-project.org > Subject: [R] sem error "no variance or error-variance parameter" >

[R] sem error "no variance or error-variance parameter"

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.

[R] sem error "no variance or error-variance parameter"

Hi, 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-a

Re: [R] SEM error

Dear Jarret, Uwe, and Dan, Sorry -- I missed the initial question. What's a bit odd here is that the singularity occurs only in the computation of the modification indices. It might help to look at the conditioning of the covariance matrix of the parameter estimates (i.e., the eigenvalues or si

Re: [R] SEM error

I have often found this to happen if the scale of one variable is orders of magnitude different than the scale of other variables. Have you tried inspecting the covariance matrix and log transforming any such variables? On Feb 22, 2010, at 8:14 AM, Uwe Ligges wrote: On 20.02.2010 08:51

Re: [R] SEM error

On 20.02.2010 08:51, Dan Edgcumbe wrote: I'm trying to do some confirmatory factor analysis on some data. My SEM model solves in 22 iterations, but when I try to look at the modification indices, using mod.indices, I get the following error message: Error in solve.default(hessian) : system

[R] SEM error

I'm trying to do some confirmatory factor analysis on some data. My SEM model solves in 22 iterations, but when I try to look at the modification indices, using mod.indices, I get the following error message: Error in solve.default(hessian) : system is computationally singular: reciprocal condit