specify_uni_lcsm {lcsm}

Specify lavaan model for univariate latent change score models

Description

Specify lavaan model for univariate latent change score models

Usage

specify_uni_lcsm(timepoints, var, model, add = NULL, change_letter = "g")

Arguments

timepoints

Number if timepoints.

var

String, specifying letter to be used for of variables (Usually x or y).

model

List of model specifications (logical) for the variables specified in variable.

• alpha_constant: Constant change factor,

• alpha_piecewise: Piecewise constant change factors,

• alpha_piecewise_num: Changepoint of piecewise constant change factors,

• alpha_linear: Linear change factor,

• beta: Proportional change factor,

• phi: Autoregression of change scores.

add

String, lavaan syntax to be added to the model

change_letter

String, specifying letter to be used for change factor (Usually g or j).

Value

Lavaan model syntax including comments.

References

Ghisletta, P., & McArdle, J. J. (2012). Latent Curve Models and Latent Change Score Models Estimated in R. Structural Equation Modeling: A Multidisciplinary Journal, 19(4), 651–682. doi:10.1080/10705511.2012.713275.

Grimm, K. J., Ram, N., & Estabrook, R. (2017). Growth Modeling—Structural Equation and Multilevel Modeling Approaches. New York: The Guilford Press.

McArdle, J. J. (2009). Latent variable modeling of differences and changes with longitudinal data. Annual Review of Psychology, 60(1), 577–605. doi:10.1146/annurev.psych.60.110707.163612.

Yves Rosseel (2012). lavaan: An R Package for Structural Equation Modeling. Journal of Statistical Software, 48(2), 1-36. doi:10.18637/jss.v048.i02.

Examples

# Specify univariate LCSM
lavaan_uni_lcsm_01 <- specify_uni_lcsm(timepoints = 10, 
                                       model = list(alpha_constant = TRUE, 
                                                    beta = TRUE, 
                                                    phi = TRUE), 
                                       var = "x",  
                                       change_letter = "g")
                 
#' # To look at string simply return the object                                    
lavaan_uni_lcsm_01

# To get a readable output use cat() function
cat(lavaan_uni_lcsm_01)