Feature Request: Add support for lavaan objects in equivalence_test()

Fixes #1176

Author: strengejacke

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: parameters
 Title: Processing of Model Parameters
-Version: 0.29.1.4
+Version: 0.29.1.5
 Authors@R:
     c(person(given = "Daniel",
              family = "Lüdecke",
@@ -234,3 +234,4 @@ Config/Needs/website: easystats/easystatstemplate
 Config/Needs/check: stan-dev/cmdstanr
 Config/rcmdcheck/ignore-inconsequential-notes: true
 Config/roxygen2/version: 8.0.0
+Remotes: easystats/insight

NAMESPACE

@@ -152,6 +152,7 @@ S3method(equivalence_test,glm)
 S3method(equivalence_test,glmmTMB)
 S3method(equivalence_test,gls)
 S3method(equivalence_test,hurdle)
+S3method(equivalence_test,lavaan)
 S3method(equivalence_test,lm)
 S3method(equivalence_test,lme)
 S3method(equivalence_test,merMod)
@@ -589,13 +590,6 @@ S3method(plot,parameters_p_function)
 S3method(plot,parameters_pca)
 S3method(plot,parameters_sem)
 S3method(plot,parameters_simulate)
-S3method(predict,cluster_analysis)
-S3method(predict,cluster_meta)
-S3method(predict,kmeans)
-S3method(predict,parameters_clusters)
-S3method(predict,parameters_efa)
-S3method(predict,parameters_pca)
-S3method(predict,parameters_sem)
 S3method(principal_components,data.frame)
 S3method(principal_components,lm)
 S3method(principal_components,merMod)
@@ -710,6 +704,7 @@ S3method(simulate_model,gls)
 S3method(simulate_model,hurdle)
 S3method(simulate_model,iv_robust)
 S3method(simulate_model,ivreg)
+S3method(simulate_model,lavaan)
 S3method(simulate_model,list)
 S3method(simulate_model,lm)
 S3method(simulate_model,lmRob)
@@ -1008,6 +1003,13 @@ export(p_value_satterthwaite)
 export(parameters)
 export(parameters_type)
 export(pool_parameters)
+export(predict.cluster_analysis)
+export(predict.cluster_meta)
+export(predict.kmeans)
+export(predict.parameters_clusters)
+export(predict.parameters_efa)
+export(predict.parameters_pca)
+export(predict.parameters_sem)
 export(principal_components)
 export(print_html)
 export(print_md)

NEWS.md

@@ -1,5 +1,10 @@
 # parameters (devel)
 
+## Changes
+
+* `simulate_model()`, `simulate_parameters()` and `equivalence_test()` now work
+  for `lavaan` objects.
+
 ## Bug fixes
 
 * Fixed issues with extracting wrong standard errors for model with frailty

R/5_simulate_model.R

@@ -64,7 +64,13 @@ simulate_model.default <- function(model, iterations = 1000, component = "all",
   # check for valid input
   .is_model_valid(model)
 
-  out <- .simulate_model(model, iterations, component = "conditional", effects = "fixed", ...)
+  out <- .simulate_model(
+    model,
+    iterations,
+    component = "conditional",
+    effects = "fixed",
+    ...
+  )
 
   class(out) <- c("parameters_simulate_model", class(out))
   attr(out, "object_name") <- insight::safe_deparse_symbol(substitute(model))
@@ -222,18 +228,42 @@ simulate_model.brmultinom <- simulate_model.default
 #' @export
 simulate_model.bracl <- simulate_model.default
 
+#' @export
+simulate_model.lavaan <- function(model, iterations = 1000, ...) {
+  insight::check_if_installed("lavaan")
+  if (is.null(iterations)) {
+    iterations <- 1000
+  }
 
-# helper -----------------------------------------
+  beta_mu <- lavaan::coef(model)
+  varcov <- insight::get_varcov(model, ...)
+  out <- as.data.frame(.mvrnorm(n = iterations, mu = beta_mu, Sigma = varcov))
+
+  class(out) <- c("parameters_simulate_model", class(out))
+  attr(out, "object_name") <- insight::safe_deparse_symbol(substitute(model))
+  out
+}
 
 
-.simulate_model <- function(model,
-                            iterations,
-                            component = "conditional",
-                            effects = "fixed",
-                            ...) {
-  if (is.null(iterations)) iterations <- 1000
+# helper -----------------------------------------
+
+.simulate_model <- function(
+  model,
+  iterations,
+  component = "conditional",
+  effects = "fixed",
+  ...
+) {
+  if (is.null(iterations)) {
+    iterations <- 1000
+  }
 
-  params <- insight::get_parameters(model, effects = effects, component = component, verbose = FALSE)
+  params <- insight::get_parameters(
+    model,
+    effects = effects,
+    component = component,
+    verbose = FALSE
+  )
   beta_mu <- stats::setNames(params$Estimate, params$Parameter) # Transform to named vector
 
   # "..." allow specification of vcov-args (#784)
@@ -268,7 +298,8 @@ simulate_model.bracl <- simulate_model.default
     insight::format_error("`Sigma` is not positive definite.")
   }
 
-  X <- drop(mu) + eS$vectors %*% diag(sqrt(pmax(ev, 0)), p) %*% t(matrix(stats::rnorm(p * n), n))
+  X <- drop(mu) +
+    eS$vectors %*% diag(sqrt(pmax(ev, 0)), p) %*% t(matrix(stats::rnorm(p * n), n))
   nm <- names(mu)
 
   dn <- dimnames(Sigma)