R/cfa_invariance_test.r

In masurp/pmstats: Customized Functions for Statistical Computations, Result Extractions, and Reporting

#' SEM model comparison (Chisquare-test)
#' 
#' This function creates a data frame that display a classical Chisqare-test of differently configured SEM/CFA models. This function is similarly written as \code{\link[pmstats]{cfa_invariance_fit}}. Both functions are meant to be used together.
#' 
#' @param ... Objects objects of class \code{lavaan} (e.g., with base, weak, strong and strict invariance constraints). 
#' @param model_names Do you want to rename the models? Provide a vector with the respective model names.
#' @param print A logical value indicating whether table shoud be formatted according to APA-guidelines.
#' @examples 
#' library(lavaan)
#' d <- PoliticalDemocracy %>% na.omit
#' model_1 <- '
#'   # latent variables
#'   ind60 =~ x1 + x2 + x3
#'   dem60 =~ y1 + y2 + y3 + y4
#'   dem65 =~ y5 + y6 + y7 + y8
#' '
#' fit_1 <- cfa(model_1, data = d)
#' 
#' model_2 <- '
#'   # latent variables
#'   ind60 =~ x1 + x2 + x3
#'   dem60 =~ y1 + y2 + y3
#'   dem65 =~ y5 + y6 + y7 + y8
#' '
#' fit_2 <- cfa(model_2, data = d)
#' 
#' # Model comparison
#' cfa_invariance_test(fit_1, fit_2)
#' 
#' # Renaming model names
#' cfa_invariance_test(fit_1, fit_2, model_names = c("Model 1: All variables", "Model 2: Some omissions"), print = TRUE)
#' @export
cfa_invariance_test <- function(...,
                                model_names = NULL,
                                print = FALSE){
  # dependencies
  library(lavaan)
  library(tidyverse)
  library(magrittr)
  library(papaja)
  
  # subfunctions
  names_from_dots <- function(...) sapply(substitute(list(...))[-1], deparse)
  
  # Getting model names
  model <- names_from_dots(...)
  
  ## Length of dots
  length_dots <- length(list(...))
  
  # function
  temp <- anova(...) %>%
    as.tibble %>%
    set_colnames(c("df", "aic", "bic", "chisq", "chisq_diff", "df_diff", "p"))
  
  temp <- temp %>%
    bind_cols(model = model) %>%
    select(model, everything())
  
  if (!is.null(model_names)) {
    temp <- temp %>%
      mutate(model = model_names)
  }
  
  if (isTRUE(print)) {
    temp2 <- temp %>%
      mutate(p = as.character(p),
             chisq_diff = printnum(chisq_diff))
    temp2[2:length_dots,8] <- temp[2:length_dots,8] %>% 
      mutate(p = printp(p))
    temp2[1, 6:8] <- ""
    
    return(temp2)
    
  } else {
  
  return(temp)
    
  }
  
}