= R lavann =

'''lavann''' is a [[Statistics/StructuralEquationModeling|SEM]] fitting software.

<<TableOfContents>>

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== Installation ==

{{{
install.package('lavaan')
}}}

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== Usage ==

{{{
"
Y =~ y1 + y2 + y3
X =~ x1 + x2 + x3
Z =~ z1 + z2 + z3
Y ~ X + Z
" |>
  sem(data = data, std.lv = TRUE) |>
  lavaanPlot(coefs = TRUE)
}}}

This displays:
 * chi-squared test statistic for the model
 * regression coefficients for the measurement model(s), including Z statistics, under the '''Latent Variables''' header.
 * regression coefficients for the structural model, including Z statistics, under the '''Regression''' header
 * covariances among latent variables, including Z statistics
 * variances of observed variables, including Z statistics
   * Note that certain variances are forced to be 1 by assumption; in this case the variances of latent variables (i.e., `X` and `Z`) and the variance of the outcome variable's errors  (i.e. `.Y`; the leading dot indicates a variance).

lavaan estimates latent variances whereas [[Stata/Gsem|gsem]] fits data to a model using maximum likelihood. While regression coefficients can be comparable, the methods are fundamentally not.



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CategoryRicottone