README.md

In brandmaier/onyxR: Interface to call Onyx from R

onyxR

An R package for calling Onyx GUI from R when using OpenMx or lavaan packages for Structural Equation Modelling. The package provides a simple onyx() function that takes either an OpenMx model or a lavaan model (either a fitted lavaan model or string specification). If a local onyx executable is available, its path can be passed to the function. Otherwise, it will attempt to download a copy of Onyx from the official repository. A recent version of JAVA (version 1.6+) is required to be installed on the system.

Install

To install the onyxR package directly from GitHub, copy the following line into R: ```{r, eval=FALSE} source('https://raw.githubusercontent.com/brandmaier/onyxR/master/tools/install.R')

## Usage

Using onyxR is as simple as that. In lavaan

````{r, eval=FALSE}
HS.model <- ' visual  =~ x1 + x2 + x3 
              textual =~ x4 + x5 + x6
              speed   =~ x7 + x8 + x9 '

fit <- cfa(HS.model, data = HolzingerSwineford1939)

summary(fit, fit.measures = TRUE)

onyx(fit)
````

Alternatively, we can use onyxR to generate a path diagram for an OpenMx RAM-type model:

````{r, eval=FALSE}
data(demoOneFactor)
manifests <- names(demoOneFactor)
latents <- c("G")
factorModel <- mxModel("One Factor",
                       type="RAM",
                       manifestVars = manifests,
                       latentVars = latents,
                       mxPath(from=latents, to=manifests),
                       mxPath(from=manifests, arrows=2),
                       mxPath(from=latents, arrows=2,
                              free=FALSE, values=1.0),
                       mxData(cov(demoOneFactor), type="cov",
                              numObs=500))
fit <- mxRun(factorModel)

onyx(fit)
````

![openmx](https://github.com/brandmaier/onyxR/blob/master/inst/openmx-factor.png?raw=true)

## Demo

In a simple demo, we have wrapped the above example.  We define the HS model with three independent factors in lavaan and pass this to Onyx to display the path diagram.
````{r, eval=FALSE}
require(onyxR)
demo(lavaanHS)

brandmaier/onyxR documentation built on Nov. 5, 2021, 11:04 a.m.