The third beta of OpenMx version 2.0 is now publicly available! Interested users can download and install this new version by copy-pasting source('https://openmx.ssri.psu.edu/getOpenMxBeta.R')
into the R command line and pressing 'Return'. Documentation for the beta is available here.
Compared to the second beta, the performance of this release is much improved. The second beta actually introduced a performance decrement in full information maximum likelihood (FIML) analyses that has now been corrected. Further, Item Factor Analysis (IFA) models now converge much more quickly, due to implementation of an improved expectation-maximization algorithm.
CSOLNP, a new, open-source numerical optimizer written in C++, was introduced in the first beta. Several CSOLNP-related bugs have now been fixed. Additionally, a bug with mxFitFunctionMultigroup()
has been fixed.
This release also features a new function, mxTryHard()
. This function makes multiple attempts at running a model until an acceptable solution is reached. Between attempts, it randomly "jiggles" the most recent set of parameter estimates and uses them as start values on the next attempt.
Users should be aware of the following issues:
$
accessor instead of the @
accessor. For example, myModelRun@output$estimate
would now be myModelRun$output$estimate
. We CANNOT guarantee that every usage of the @
accessor that worked with versions 1.3/1.4 will continue to work in 2.0.
We are eager to receive user feedback about this beta of OpenMx 2.0! Please post questions, comments, and issues to the OpenMx Forums.