MplusAutomation

The MplusAutomation package leverages the flexibility of the R language to automate latent variable model estimation and interpretation using Mplus, a powerful latent variable modeling program developed by Muthén and Muthén (www.statmodel.com). Specifically, MplusAutomation provides routines for creating related groups of models, running batches of models, and extracting and tabulating model parameters and fit statistics.

Installation

You can install the latest release of MplusAutomation directly from CRAN by running

install.packages("MplusAutomation")

Alternately, if you want to try out the latest development MplusAutomation code, you can install it straight from github using Hadley Wickham's devtools package. If you do not have devtools installed, first install it and then install MplusAutomation.

#install.packages("devtools")
require(devtools)

install_github("MplusAutomation", "michaelhallquist")

Questions

For questions, answers, and updates on the status of the MplusAutomation package, email or subscribe to the Google group list.

Examples

You can find a detailed example of how to use the MplusAutomation package in the vignette .

Here is an example of using the package to run a simple path model using the mtcars dataset built into R.

library(MplusAutomation)

pathmodel <- mplusObject(
   TITLE = "MplusAutomation Example - Path Model;",
   MODEL = "
     mpg ON hp;
     wt ON disp;",
   rdata = mtcars)

## No R variables to use specified.
## Selected automatically as any variable name that occurs in the MODEL or DEFINE section.

fit <- mplusModeler(pathmodel, "mtcars.dat", modelout = "model1.inp", run = 1L)

## Wrote model to: model1.inp
## Wrote data to: mtcars.dat

##
## Running model: model1.inp
## Reading model:  model1.out

That is all it takes to run Mplus! MplusAutomation takes care of figuring out which variables from your R dataset are used in the model and which are not (if it get's confused, you can also specify usevariables). It creates a dataset suitable for Mplus, calls Mplus to run the model on the dataset, and reads it back into R.

There is even pretty printing now. To see the results:

library(texreg)
screenreg(fit, summaries = c("Observations", "CFI", "SRMR"), single.row=TRUE)

==================================
                  Model 1
----------------------------------
 MPG<-HP          -0.06 (0.01) ***
 WT<-DISP          0.01 (0.00) ***
 WT<->MPG         -1.02 (0.38) **
 MPG<-Intercepts  29.59 (1.53) ***
 WT<-Intercepts    1.82 (0.18) ***
 MPG<->MPG        14.04 (3.52) ***
 WT<->WT           0.21 (0.06) ***
----------------------------------
Observations      32
CFI                0.87
SRMR               0.14
==================================
*** p < 0.001, ** p < 0.01, * p < 0.05

The fit is not great, to add some extra paths we can update the model.

pathmodel2 <- update(pathmodel, MODEL = ~ . + "
    mpg ON disp;
    wt ON hp;")

fit2 <- mplusModeler(pathmodel2, "mtcars2.dat", modelout = "model2.inp", run = 1L)

## Wrote model to: model2.inp
## Wrote data to: mtcars2.dat

## Warning: The file 'mtcars2.dat' currently exists and will be overwritten

##
## Running model: model2.inp
## Reading model:  model2.out

We can make some pretty output of both models:

screenreg(list(
  extract(fit, summaries = c("Observations", "CFI", "SRMR")),
  extract(fit2, summaries = c("Observations", "CFI", "SRMR"))),
  single.row=TRUE)

====================================================
                  Model 1           Model 2
----------------------------------------------------
 MPG<-HP          -0.06 (0.01) ***  -0.02 (0.01)
 WT<-DISP          0.01 (0.00) ***   0.01 (0.00) ***
 WT<->MPG         -1.02 (0.38) **   -0.73 (0.26) **
 MPG<-Intercepts  29.59 (1.53) ***  30.74 (1.27) ***
 WT<-Intercepts    1.82 (0.18) ***   1.68 (0.19) ***
 MPG<->MPG        14.04 (3.52) ***   8.86 (2.21) ***
 WT<->WT           0.21 (0.06) ***   0.19 (0.05) ***
 MPG<-DISP                          -0.03 (0.01) ***
 WT<-HP                              0.00 (0.00)
----------------------------------------------------
Observations      32                32
CFI                0.87              1.00
SRMR               0.14              0.00
====================================================
*** p < 0.001, ** p < 0.01, * p < 0.05

How to Help

If you have a tutorial or examples using MplusAutomation, please add them to the github Wiki.

In addition, on the Wiki, is a list of publications that cite or use MplusAutomation. If you use MplusAutomation in your own work --- papers, posters, presentations, etc. --- please add a citation to the list, and if possible, include an abstract or link to the full text. This helps us get to know our users and how MplusAutomation is being used.

Finally, if you find bugs or have suggestions for new features or ways to enhance MplusAutomation, please let us know! Just click the 'Issues' button at the top of the github page or go here and open a New Issue.

Lastly, if you use MplusAutomation and have space, we greatly appreciating citations. In addition to being easier to track, the recognition and credit help make it easier for us to continue putting our time into developing and sharing this software!