Displaying 20 results from an estimated 6000 matches similar to: "Changed results in analyses run in sem and nlme ??"
2011 Dec 01
3
FIML with missing data in sem package
Is there a way to use full information maximum likelihood (FIML) to
estimate missing data in the sem package? For example, suppose I have a
dataset with complete information on X1-X3, but missing data (MAR) on X4.
Is there a way to use FIML in this case? I know lavaan and openmx allow you
to do it, but I couldn't find anything in the documentation for the sem
package. Thanks!
--
Dustin Fife
2006 Jul 13
1
sem question
Dear all,
I am trying to estimate simultaneous equation model concerning growth in russian regions.
I run the analysis by means of FIML in R sem package.
I am not familiar with SEM yet, but I've just got several suitable estimated specifications.
Nevertheless, sometimes R gives the following warning message:
Warning message:
Negative parameter variances.
Model is probably underidentified.
2012 Jul 12
1
easy way to fit saturated model in sem package?
Hi,
I am wondering if anyone knows of an easy way to fit a saturated model
using the sem package on raw data? Say the data were:
mtcars[, c("mpg", "hp", "wt")]
The model would estimate the three means (intercepts) of c("mpg",
"hp", "wt"). The variances of c("mpg", "hp", "wt"). The covariance
of mpg with
2011 Nov 07
0
new version 2.0-0 of the sem package
Dear R users,
Jarrett Byrnes and I would like to announce version 2.0-0 of the sem package
for fitting observed- and latent-variable structural equation models. This
is a general reworking of the original sem package (which is still available
on R-Forge as package sem1).
Some highlights of sem 2.0-0 include:
o More convenient and compact model specification, including the default
automatic
2011 Nov 07
0
new version 2.0-0 of the sem package
Dear R users,
Jarrett Byrnes and I would like to announce version 2.0-0 of the sem package
for fitting observed- and latent-variable structural equation models. This
is a general reworking of the original sem package (which is still available
on R-Forge as package sem1).
Some highlights of sem 2.0-0 include:
o More convenient and compact model specification, including the default
automatic
2013 Apr 23
2
Frustration to get help R users group
Dear R users/developers
I requested help to solve the problem of formulating Multivariate Sample
selection model by using Full Information Maximum Likelihood
(FIML)estimation method. I could not get any response. I formulated the
following code of FIML to analyse univariate sample selection problem.
Would you please advise me where is my problem
library (sem)
library(nrmlepln)
Selection
2012 Mar 29
1
FIML in R
Does anyone know if someone is developing full-information maximum likelihood (FIML) estimation algorithms for basic regression functions, like glm()? I think that having FIML options for workhorse functions that typically use ML would give R an edge over other statistical software, given how well FIML performs in missing data situations compared to ML.
While my current level of programming
2013 Apr 17
0
Full Information Maximum Likelihood estimation method for multivariate sample selection problem
Dear R experts/ users
Full Information Maximum Likelihood (FIML) estimation approach is
considered robust over Seemingly Unrelated Regression (SUR) approach
for analysing data of multivariate sample selection problem. The zero
cases in my dependent variables are resulted from three sources:
Irreverent options, not choosing due to negative utility and not used
in the reported time. FIML can
2011 Feb 08
1
SEM: question regarding how standard errors are calculated
Sorry if this question has been asked previously, I searched but found
little. There also doesn't seem to be a dedicated SEM list-serv so hopefully
this will find its way to the appropriate audience.
In discussing SEM with a colleague I mentioned that a model they were
fitting in AMOS was equivalent to a linear regression and that the
coefficients would be the same. This of course was the
2012 Jul 20
1
FIML using lavaan returns zeroes for coefficients
Hello!
I am trying to reproduce (for a publication) analyses that I ran several months ago using lavaan, I'm not sure which version, probably 0.4-12. A sample model is given below:
pathmod='mh30days.log.w2 ~ mh30days.log + joingroup + leavegroup + alwaysgroup + grp.partic.w2 + black + age + bivoc + moved.conf + local.noretired + retired + ds + ministrytime + hrswork + nomoralescore.c +
2006 Jul 17
1
sem: negative parameter variances
Dear Spencer and Prof. Fox,
Thank you for your replies. I'll very appreciate, if you have any ideas concerning the problem described below.
First, I'd like to describe the model in brief.
In general I consider a model with three equations.
First one is for annual GRP growth - in general it looks like:
1) GRP growth per capita = G(investment, migration, initial GRP per
2004 Aug 27
4
FIML in lme
Hi
I was asked if lme can use FIML (Full Information Maximum Likelihood)
instead of REML or ML but I don't know the answer. Does anybody know if
this is implemented in R?
Thanks
Francisco
2009 Feb 02
1
sem package and AMOS
Hello-
I am using R to build my initial models, but need to use AMOS to compare
the models of two groups (adults vs. kids). The problem is I am getting
different results with R and AMOS for the initial models of the separate
groups (and the R results make more sense).
The parameter estimates (path coefficients and variances) from both
programs are nearly identical, but the model chi-squares
2002 Jul 18
1
sem: incorrect parameter estimates
Hello.
I am getting results from sem that are not correct (that's assuming
that the results from my AMOS 4.0 software are correct). sem does not
vary some of the parameters substantially from their starting values,
and the final estimates of those parameters as well as the model
chisquare value are incorrect. I've attached some code that
replicates the problem. The parameters in
2008 Jun 03
0
Summarizing dummy coefficients in sem package
Greetings,
I am working in the sem package on a model with 3 exogenous variables (2
are nominal-categorical), and 4 endogenous, continuous variables. To
use sem with the nominal variables, I created dummy variables. Now, in
my sem output I have estimates for path coefficients for the
relationship between each level of the nominal variables and the
endogenous variables they are associated
2008 Dec 11
0
Equivalent to Full Information Maximum Likelihood (FIML) in R?
Is there an equivalent to MPlus's Full Information Maximum Likelihood (FIML)
missing data estimator for R? If so, is there a way to take covariance
structures produced by such a package and perform multiple regression with
these?
If you are unfamiliar with Mplus' FIML below is a link to their manual.
Their estimation technology is discussed on page 25. I have asked the
developer of the
2010 May 19
0
New package: `lavaan' for latent variable analysis (including structural equation modeling)
Dear R-users,
A new package called `lavaan' (for latent variable analysis) has been
uploaded to CRAN. The current version of lavaan (0.3-1) can be used for
path analysis, confirmatory factor analysis, structural equation
modeling, and growth curve modeling.
More information can be found on the website: http://lavaan.org
Some notable features of lavaan:
- the 'lavaan model
2010 May 19
0
New package: `lavaan' for latent variable analysis (including structural equation modeling)
Dear R-users,
A new package called `lavaan' (for latent variable analysis) has been
uploaded to CRAN. The current version of lavaan (0.3-1) can be used for
path analysis, confirmatory factor analysis, structural equation
modeling, and growth curve modeling.
More information can be found on the website: http://lavaan.org
Some notable features of lavaan:
- the 'lavaan model
2002 May 30
2
Systems of equations in glm?
I have a student that I'm encouraging to use R rather than SAS or Stata
and within just 2 weeks he has come up with a question that stumps me.
What does a person do about endogeneity in generalized linear models?
Suppose Y1 and Y2 are 5 category ordinal dependent variables. I see
that MASS has polr for estimation of models like that, as long as they
are independent. But what if the
2006 Nov 20
1
sem package subscript out of bounds error
I'm having the most curious error while using the sem package. For
the model I'm working with, I keep getting the following error:
Error in J[cbind(1:n, observed)] <- 1 : subscript out of bounds
I''ve used debug=TRUE with sem, and there don't appear to be any
problems with model - there are no latent variables in this model.
The variables in the covariance matrix