scriptUni: A Function That Writes, Saves, and Exports Syntax for Fitting Unidimensional Dyadic Factor Models

Description

This function takes the outputted object from scrapeVarCross() and automatically writes, returns, and exports (.txt) lavaan syntax for specifying dyadic configural, loading, intercept, and residual invariant one-factor models.

Usage

scriptUni(
  dvn,
  scaleset = "FF",
  lvname = "X",
  constr_dy_meas = c("loadings", "intercepts", "residuals"),
  constr_dy_struct = "none",
  writeTo = NULL,
  fileName = NULL
)

Value

Character object of lavaan script that can be passed immediately to lavaan functions.

Arguments

dvn: Input dvn list from scrapeVarCross().
scaleset: Input character to specify how to set the scale of the latent variable. Default is "FF" (fixed-factor; see Details for rationale), but user can specify "MV" (Marker Variable).
lvname: Input character to (arbitrarily) name the latent variable in lavaan syntax.
constr_dy_meas: Input character vector detailing which measurement model parameters to constrain across dyad members.
constr_dy_struct: Input character vector detailing which structural model parameters to constrain across dyad members. Note: Within the context of scriptUni(), constr_dy_struct is irrelevant, as the unidimensional dyadic factor model assumes a single latent variable shared by both partners, leaving no structural parameters to constrain across the modeled dyad members. For consistency with other scripter functions, constr_dy_struct is included as an argument, but defaults to "none".
writeTo: A character string specifying a directory path to where a .txt file of the resulting lavaan script should be written. If set to “.”, the .txt file will be written to the current working directory. The default is NULL, and examples use a temporary directory created by tempdir().
fileName: A character string specifying a desired base name for the .txt output file. The default is NULL. The specified name will be automatically appended with the .txt file extension. If a file with the same name already exists in the user's chosen directory, it will be overwritten.

Details

Users do not need to modify constr_dy_struct when using scriptUni().
By default, many dySEM:: functions (including scriptUni()) default to a fixed-factor method of scale-setting, whereby the latent variance of a given factor is constrained to 1 for both partners in the configurally invariant model, and then one of these variances is freely estimated in subsequent models of the invariance testing sequence. We have selected this default for two reasons: (1) the selection of a marker-variable is usually arbitrary, yet can have a large influence on the estimation and testing of of structural parameters (see https://stats.stackexchange.com/questions/402133/in-cfa-does-it-matter-which-factor-loading-is-set-to-1/402732#402732); and (2) the selection of a non-invariant marker-variable can have disastrous down-stream consequences for the identification of non-invariant measurement parameters, following a the rejection of an omnibus invariance constraint set (see Lee, Preacher, & Little, 2011).

Examples

Run this code


dvn <- scrapeVarCross(
  commitmentQ,
  x_order = "spi",
  x_stem = "sat.g",
  x_delim1 = ".",
  x_delim2 = "_",
  distinguish_1 = "1",
  distinguish_2 = "2"
)

sat.resids.script <- scriptUni(
  dvn,
  scaleset = "FF",
  lvname = "Sat",
  constr_dy_meas = c("loadings", "intercepts", "residuals"),
  constr_dy_struct = "none",
  writeTo = tempdir(),
  fileName = "dUni_residual"
)

sat.ints.script <- scriptUni(
  dvn,
  scaleset = "FF",
  lvname = "Sat",
  constr_dy_meas = c("loadings", "intercepts"),
  constr_dy_struct = "none",
  writeTo = tempdir(),
  fileName = "dUni_intercept"
)

sat.loads.script <- scriptUni(
  dvn,
  scaleset = "FF",
  lvname = "Sat",
  constr_dy_meas = c("loadings"),
  constr_dy_struct = "none",
  writeTo = tempdir(),
  fileName = "dUni_loading"
)

sat.config.script <- scriptUni(
  dvn,
  scaleset = "FF",
  lvname = "Sat",
  constr_dy_meas = "none",
  constr_dy_struct = "none",
  writeTo = tempdir(),
  fileName = "dUni_configural"
)