iced_syntax {ICED}

iced_syntax function - generates lavaan syntax for ICED models

Description

The function takes a dataframe describing the data structure and returns lavaan syntax to run the model

Usage

iced_syntax(
  structure,
  fix_lower_bounds = TRUE,
  set_variances = NULL,
  e_label = "e",
  print = TRUE,
  groups = NULL,
  groups_inequality = NULL
)

Arguments

structure

data.frame describing the structure of the data, with each variable covering a design aspect - see example. Note: currently the first variable must be time and include a different value for each repeated measure.

fix_lower_bounds

fixes error variance estimates to be positive, defaults to TRUE

set_variances

allows the user to specify a list of variances for each latent variable

e_label

user defined variable name of the error variance. defaults to "e"

print

option to print the syntax to the console. defaults to TRUE

groups

allows the user to specify a number or list of group names. The syntax will generate separate latent variable variances to estimate for each group

groups_inequality

allows the user to specify which variance components they wish to allow to vary between groups. Useful for model comparisons.

Value

returns a character string for the ICED model following lavaan syntax

Examples

## see online documentation for full examples
# https://github.com/sdparsons/ICED
structure <- data.frame(time = c("T1", "T2", "T3", "T4"),
                        day = c("day1","day1","day2","day2"),
                        session = c("session1", "session1","session2", "session3"))