R/sem_modelcomp.R

In dr-JT/semoutput: SEM Output

#' Model comparison
#'
#' This function will display a table of Model significance tests
#' @param m0 A lavaan model.
#' @param m1 A lavaan model.
#' @param digits How many digits to display? (default = 3)
#' @param print Create a knitr table for displaying as html table.
#' @export
#'

sem_modelcomp <- function(m0, m1, digits = 3, print = TRUE) {
  # Get names of model objects to use in output
  m0_name <- as.character(substitute(m0))
  m1_name <- as.character(substitute(m1))

  # Get values to be used in the table
  stats <- lavaan::anova(m0, m1)

  # Create table
  table <- suppressWarnings(broom::tidy(stats))
  table <- dplyr::rename(table, Model = term,
                         Chi_Square = statistic)
  table <- dplyr::mutate(table, Model = ifelse(Model == "m0",
                                               m0_name, m1_name))
  table <- dplyr::arrange(table, dplyr::desc(df))
  table <- dplyr::mutate(table,
                         row = dplyr::row_number(),
                         Chi_Square_diff = ifelse(row == 2,
                                             dplyr::first(Chisq.diff), NA),
                         df_diff = ifelse(row == 2,
                                          dplyr::first(Df.diff), NA),
                         p = ifelse(row == 2,
                                    dplyr::first(p.value), NA),
                         BF =
                           ifelse(row == 1,
                                  exp((dplyr::last(BIC) -
                                         dplyr::first(BIC)) / 2),
                                  exp((dplyr::first(BIC) -
                                         dplyr::last(BIC)) / 2)),
                         `P(Model|Data)` = BF / (BF + 1))
  table <- dplyr::select(table, Model, df, AIC, BIC, BF, `P(Model|Data)`,
                         Chi_Square, Chi_Square_diff,
                         df_diff, p)

  # Print table
  if (print == TRUE) {

    table_title <- "Model Comparison"

    table <- gt::gt(table) |>
      table_styling() |>
      gt::tab_header(title = table_title) |>
      gt::cols_label(Chi_Square = gt::html("&chi;<sup>2</sup>"),
                     Chi_Square_diff = gt::html("&Delta;&chi;<sup>2</sup>"),
                     df_diff = gt::html("&Delta;df")) |>
      gt::sub_small_vals(columns = p, threshold = .001) |>
      gt::fmt_number(decimals = digits, use_seps = FALSE) |>
      gt::fmt_number(columns = df, decimals = 0, use_seps = FALSE)
  }

  return(table)
}