[2] OpenMx consists of an R library of functions and optimizers supporting the rapid and flexible implementation and estimation of SEM models.

RAM models return standardized and raw estimates, as well as a range of fit indices (AIC, RMSEA, TLI, CFI etc.).

For models that are better suited to description in terms of matrix algebra, this is done using similar functional extensions in the R environment, for instance mxMatrix and mxAlgebra.

The code below shows how to implement a simple Confirmatory factor analysis in OpenMx, using either path or matrix formats.

Below is the code to implement, run, and print a summary for estimating a one-factor path model with five indicators.