[R-pkgs] New package: `lavaan' for latent variable analysis (including structural equation modeling)

[Yves Rosseel]

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 syntax' allows users to express their models in a 
compact, elegant and useR-friendly way

- lavaan is robust and reliable: there are no convergence problems and 
numerical results are very close (if not identical) to the commercial 
package Mplus

- many different estimators are available: ML, GLS, WLS, robust ML using 
Satorra-Bentler corrections, and FIML for data with missing values

- full support for meanstructures and multiple groups

- user friendly output including standardized solutions, fit measures, 
modification indices and more

To get a first impression of how the 'lavaan model syntax' looks like, 
below is the full R code for fitting a SEM model:

## begin R Code ##

library(lavaan)

# The industrialization and Political Democracy Example
# Bollen (1989), page 332

model <- '
   # latent variable definitions
      ind60 =~ x1 + x2 + x3
      dem60 =~ y1 + y2 + y3 + y4
      dem65 =~ y5 + y6 + y7 + y8

   # regressions
     dem60 ~ ind60
     dem65 ~ ind60 + dem60

   # residual correlations
     y1 ~~ y5
     y2 ~~ y4 + y6
     y3 ~~ y7
     y4 ~~ y8
     y6 ~~ y8
'

fit <- sem(model, data=PoliticalDemocracy)
summary(fit, fit.measures=TRUE)

## end R code ##


Please feel free to contact me directly with questions and comments.

Best,

Yves Rosseel.



-- 
Yves Rosseel -- http://www.da.ugent.be
Department of Data Analysis, Ghent University
Henri Dunantlaan 1, B-9000 Gent, Belgium
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