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Fit a List of Models

Source: R/fit_many.R
fit_many.Rd

Fit a list of models to a dataset.

Usage

fit_many(
  model_list,
  sem_out,
  original = NULL,
  parallel = FALSE,
  ncores = max(parallel::detectCores(logical = FALSE) - 1, 1),
  make_cluster_args = list(),
  progress = TRUE,
  verbose = TRUE
)

Arguments

model_list

A list of parameter tables to be used by lavaan::lavaan() or update(). Usually generated by get_add() or get_drop().

sem_out

The output from an structural equation modeling function. It currently supports lavaan::lavaan objects only. Usually the one used in model_set(), get_add() or get_drop() to generate the list of models.

original

String. If provided, it should be a name of a model in model_list, with which differences in model degrees of freedom will be computed for other models. If NULL, the default, then the model in sem_out will be used to computed the differences in model degrees of freedom. If NA, then differences in model df will not be computed.

parallel

If TRUE, parallel processing will be used to fit the models. Default is FALSE.

ncores

Numeric. The number of CPU cores to be used if parallel is TRUE.

make_cluster_args

A list of named arguments to be passed to parallel::makeCluster(). Used by advanced users to configure the cluster if parallel is TRUE. Default is list().

progress

Whether a progress bar will be displayed, implemented by the pbapply package. Default is TRUE.

verbose

Whether additional messages will be displayed, such as the expected processing time. Default is TRUE.

Value

An object of the class sem_outs, a list with the following major elements:

  • fit: A named list of lavaan::lavaan() output objects or update() for fitting a model with the added parameters.

  • change: A numeric vector, of the same length as fit. The change in model df for each fit compared to the original model. A positive number denotes one less free parameter. A negative number denotes one more free parameter or one less constraint.

  • converged: A named vector of boolean values, of the same length as fit. Indicates whether each fit converged or not.

  • post_check: A named vector of boolean values, of the same length as fit. Indicates whether the solution of each fit is admissible or not. Checked by lavaan::lavInspect() with the what argument set to "post.check".

Details

It receives a list of models, defined by lavaan parameter tables (usually generated by model_set(), get_add() or get_drop()), and fit them to a dataset stored in a lavaan-class object.

This function is called by model_set() and usually users do not need to call it. It is exported for advanced users.

Author

Shu Fai Cheung https://orcid.org/0000-0002-9871-9448

Examples


library(lavaan)
#> This is lavaan 0.6-18
#> lavaan is FREE software! Please report any bugs.
dat <- dat_path_model
mod <-
"
x3 ~ a*x1 + b*x2
x4 ~ a*x1
ab := a*b
"
fit <- sem(mod, dat_path_model, fixed.x = TRUE)
mod_to_add <- get_add(fit)
fit_many(mod_to_add, fit)
#> 
#> Fit the 2 model(s) (duplicated models removed):
#> 
#> Call:
#> fit_many(model_list = mod_to_add, sem_out = fit)
#> 
#> Number of model(s) fitted: 2
#> Number of model(s) converged: 2
#> Number of model(s) passed post.check: 2
#> 
#> The modification(s)/model(s):
#> add: x4~x2
#> add: (x3~x1),(x4~x1)