R: Get the RMSEA with confidence intervals from model

omxRMSEA {OpenMx} | R Documentation

## Get the RMSEA with confidence intervals from model

### Description

This function calculates the Root Mean Square Error of the Approximation (RMSEA) for a model and computes confidence intervals for that fit statistic.

### Usage

    omxRMSEA(model, lower=.025, upper=.975, null=.05, ...)

### Arguments

`model` | An MxModel object for which the RMSEA is desired
`lower` | The lower confidence bound for the confidence interval
`upper` | The upper confidence bound for the confidence interval
`null` | Value of RMSEA used to test for close fit
`...` | Further named arguments passed to summary

### Details

To help users obtain fit statistics related to the RMSEA, this function confidence intervals and a test for close fit. The user determines how close the fit is required to be by setting the `null` argument to the value desired for comparison.

### Value

A named vector with elements lower, est.rmsea, upper, null, and 'Prob(x <= null)'.

### References

Browne, M. W. & Cudeck, R. (1992). Alternative Ways of Assessing Model Fit. Sociological Methods and Research, 21, 230-258.

### Examples

    require(OpenMx)
    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(observed=cov(demoOneFactor), type="cov", numObs=500))
    factorRun <- mxRun(factorModel)
    factorSat <- mxRefModels(factorRun, run=TRUE)
    summary(factorRun, refModels=factorSat)
    # Gives RMSEA with 95% confidence interval

    omxRMSEA(factorRun, .05, .95, refModels=factorSat)
    # Gives RMSEA with 90% confidence interval
    #  and probability of 'close enough' fit

[Package OpenMx version 2.18.1 Index]