Displaying 20 results from an estimated 120 matches similar to: "path analysis (misspecification?)"
2009 Mar 09
1
[sem package] path.diagram() ignores the edge.label argument ..?
hi,
I plot path diagrams with the path.diagram() function of the sem
package in combination with the graphviz application.
Now I want the graphviz code for a path-plot with the actual
standardized coefficients on the arrows (not the names).
I tried to add edge.labels="values" as an argument to path.diagram()
but it's just ignored.
can anyone help me on that?
p.s.;
2008 Dec 26
3
Simulating dataset using Parallel Latent CTT model?
I am trying to simulate a dataset using Parallel Latent CTT model and this is what i have done so far:
(START)
#Importing psych library for all the simulation related functions
library(psych)
# Settting the working directory path to C:/NCME
path="C:/NCME"
setwd(path)
#Using the function to generate the data
GenData <- congeneric.sim(N=500, loads =
2009 Jul 13
3
Help With Fleiss Kappa
Hi All,
I am using fleiss kappa for inter rater agreement. Are there any know
issues with Fleiss kappa calculation in R? Even when I supply mock data
with total agreement among the raters I do not get a kappa value of 1.
instead I am getting negative values.
I am using the irr package version 0.70
Any help is much appreciated.
Thanks and Regards
M
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2009 Jan 30
3
princomp - varimax - factanal
Hi!
I am trying to analyse with R a database that I have previously analysed
with SPSS.
Steps with SPSS:
Factorial analysis
Extraction options : I select = Principal component analysis
Rotation: varimax
Steps with R:
I have tried it with varimax function with factanal or with princomp...and
the results are different of what I have with SPSS. I think that varimax
function is incorporated in
2009 Jun 14
1
estimate the reliability of a scale with dichotomous items
hi,
How can I compute a reliability score of a scale consisting only of
dichotomous items?
thanks for any help!
2008 Aug 15
2
Multiple Regression with Correlation Matrix
Hello,
In SPSS, a multiple regression can be conducted by inputting the means, standard deviations, sample size, and correlation matrix without actually using the raw dataset. Is it possible to do the same in R?
Thanks in advance for your assistance.
Linda
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2009 Jan 23
1
Outputing residuals
Hello,
I was wondering if someone could tell me how to output, to file, the residuals from a REML model-fit. The type of residuals I am interested in are the simple "original raw values - model fit" type.
Thanks in advance,
Josh B.
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2008 Jul 12
1
How to build a package which loads Rgraphviz (if installed)...
Dear List,
I use Rgraphviz for display of graphs in some packages. Since Rgraphviz is no longer on CRAN it needs to be installed from Bioconductor and that is fine, but I have trouble figureing out the following: I create a plot method which - if Rgraphviz is installed - uses Rgraphviz for displaying and otherwise does nothing. This is implemented as:
if (!("package:Rgraphviz" %in%
2008 Jul 23
8
sequential sum of a vector...
Hi R,
Let,
x=1:80
I want to sum up first 8 elements of x, then again next 8 elements of x,
then again another 8 elements..... So, my new vector should look like:
c(36,100,164,228,292,356,420,484,548,612)
I used:
aggregate(x,list(rep(1:10,each=8)),sum)[-1]
or
rowsum(x,group=rep(1:10,each=8))
But without grouping, can I achieve the required? Any other ways of
doing
2009 Mar 31
3
Factor Analysis Output from R and SAS
Dear Users,
I ran factor analysis using R and SAS. However, I had different outputs from
R and SAS.
Why they provide different outputs? Especially, the factor loadings are
different.
I did real dataset(n=264), however, I had an extremely different from R and
SAS.
Why this things happened? Which software is correct on?
Thanks in advance,
- TY
#R code with example data
# A little
2007 Mar 07
1
No fit statistics for some models using sem
Hi,
New to both R and SEM, so this may be a very simple question. I am
trying to run a very simple path analysis using the sem package.
There are 2 exogenous (FARSCH, LOCUS10) and 2 endogenous (T_ATTENT,
RMTEST) observed variables in the model. The idea is that T_ATTENT
mediates the effect of FARSCH and LOCUS10 on RMTEST. The RAM
specification I used is
FARSCH -> T_ATTENT, y1x1, NA
2009 Feb 02
1
Fit indexes in SEM with categorical data + ML estimation
Hello,
It has been found that SEM analysis using polychoric correlations + maximum
likelihood estimator produces incorrect test statistics and standard errors
(e.g., Flora, D. B., & Curran, P. J. (2004). An Empirical Evaluation of
Alternative Methods of Estimation for Con?rmatory Factor Analysis With
Ordinal Data. Psychological Methods, 9(4), 466-491).
Standard errors can be dealt with by
2007 Jun 27
1
SEM model fit
I wonder if someone could explain why, when I perform confirmatory
factor-analysis model using polychoric correlations why I do not get an
estimated confidence interval for the RMSEA. My experience with these type
models is that I would obtain a confidence interval estimate. I did not get
any warning messages with the output.
RESULTS:
Model Chisquare = 1374 Df = 185 Pr(>Chisq) = 0
2009 May 27
1
Multivariate Transformations
Hello folks,
many multivariate anayses (e.g., structural equation modeling) require
multivariate normal distributions.
Real data, however, most often significantly depart from the multinormal
distribution. Some researchers (e.g., Yuan et al., 2000) have proposed a
multivariate transformation of the variables.
Can you tell me, if and how such a transformation can be handeled in R?
Thanks in
2006 Aug 16
1
Specifying Path Model in SEM for CFA
I'm using specify.model for the sem package. I can't figure out how to
represent the residual errors for the observed variables for a CFA
model. (Once I get this working I need to add some further constraints.)
Here is what I've tried:
model.sa <- specify.model()
F1 -> X1,l11, NA
F1 -> X2,l21, NA
F1 -> X3,l31, NA
F1 -> X4,l41, NA
F1 -> X5, NA, 0.20
2007 Feb 20
0
Standardized residual variances in SEM
Hello,
I'm using the "sem" package to do a confirmatory factor analysis on data
collected with a questionnaire. In the model, there is a unique factor G
and 23 items. I would like to calculate the standardized residual
variance of the observed variables. "Sem" only gives the residual
variance with the "summary" function, or the standardized loadings with
the
2004 Jul 13
5
Help with factanal and missing values
Hi list,
I'm performing a series of confirmatory factor analysis on different
groupings of items from data collected with questionnaires. There are some
missing values.
For those sets with no missing values I call
factanal(datamatrix,factors=n)
where datamatrix is a table of all observations for the items under
investigation.
This call fails when there are missing values.
help(factanal)
2006 Aug 22
1
Total (un)standardized effects in SEM?
Hi there,
as a student sociology, I'm starting to learn about SEM. The course I
follow is based on LISREL, but I want to use the SEM-package on R
parallel to it.
Using LISREL, I found it to be very usable to be able to see the
total direct and total indirect effects (standardized and
unstandardized) in the output. Can I create these effects using R? I
know how to calculate them
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