Create syntax for a batch of mixture models

Source: R/mixtures.R

Dynamically creates syntax for a batch of mixture models, with intelligent defaults. This function is a wrapper around mplusObject and mplusModeler, and the respective arguments of those functions can be passed on using .... For instance, passing the argument run = 1L means that the models will be evaluated and returned.

createMixtures(
  classes = 1L,
  filename_stem = NULL,
  model_overall = NULL,
  model_class_specific = NULL,
  rdata = NULL,
  usevariables = NULL,
  OUTPUT = "TECH11 TECH14;",
  SAVEDATA = "FILE IS {filename_stem}_{C}.dat;  SAVE = cprobabilities;",
  quiet = TRUE,
  ...
)

Arguments

classes

A vector of integers, indicating which class solutions to generate. Defaults to 1L. E.g., classes = 1:6, classes = c(1:4, 6:8).
filename_stem

Character. A stem for the automatically generated filenames of the syntax and data files.
model_overall

Character. Mplus syntax for the overall model (across classes).
model_class_specific

Character vector. Mplus syntax for the class-specific model(s) of one or more categorical latent variables. Each element of model_class_specific is used as the class-specific syntax of a different categorical latent variable. This allows one to easily specify latent transition analyses (see second example). The character string “{C}” is substituted with the correct class number, for example to set unique parameter labels for each class, or to specify equality constraints.
rdata

Data.frame. An R dataset to be used for the model.
usevariables

Character vector, specifying the names of variables in the rdata object which should be included in the Mplus data file and model.
OUTPUT

Character. Syntax for Mplus' OUTPUT option. Highly recommended when determining the appropriate number of latent classes. TECH11 is required to obtain the VLMR-test; TECH14 is required for the BLR-test.
SAVEDATA

Character. Syntax for Mplus' savedata option. Highly recommended when conducting mixture models. The default option will often be adequate.
quiet

optional. If TRUE, show status messages in the console.
...

Additional arguments, passed to mplusObject, such as syntax for other Mplus options.

Value

None, unless the argument run = 1L is specified. In that case, a list with elements of class mplusObject is returned. Otherwise, this function is used for its side effects (generating syntax).

Details

In the arguments model_class_specific and SAVEDATA, the character string “{C}” is substituted with the correct class number. The character string “{filename_stem}” is substituted with the filename stem, for example, to name savedata in line with the input files.

In all arguments to mplusObject, a double space (“ ”) is replaced with a newline character. This can be used to obtain nicely formatted Mplus syntax.

See also

mplusObject, mplusModeler

Author

Caspar J. van Lissa

Examples

if (FALSE) {
createMixtures(classes = 1:3, filename_stem = "iris", rdata = iris)
}
if (FALSE) {
data <- read.table("http://statmodel.com/usersguide/chap8/ex8.13.dat")[,c(1:10)]
names(data) <- c("u11", "u12", "u13", "u14", "u15", "u21", "u22", "u23", "u24", "u25")
createMixtures(
classes = 2,
filename_stem = "dating",
model_overall = "c2 ON c1;",
model_class_specific = c(
"[u11$1] (a{C});  [u12$1] (b{C});  [u13$1] (c{C});  [u14$1] (d{C});  [u15$1] (e{C});",
"[u21$1] (a{C});  [u22$1] (b{C});  [u23$1] (c{C});  [u24$1] (d{C});  [u25$1] (e{C});"
),
rdata = data,
ANALYSIS = "PROCESSORS IS 2;  LRTSTARTS (0 0 40 20);  PARAMETERIZATION = PROBABILITY;",
VARIABLE = "CATEGORICAL = u11-u15 u21-u25;"
)
}