R package lavaan.survey: Complex survey Structural Equation Modeling (SEM). Fit structural equation models (SEM) including factor analysis, multivariate regression models with latent variables and many other latent variable models while correcting estimates, standard errors, and chi-square-derived fit measures for a complex sampling design. Incorporate clustering, stratification, sampling weights, and finite population corrections into a SEM analysis. Wrapper around packages lavaan and survey.