Currently the svn repository has an implementation of likelihood-based confidence intervals. For the moment, the interface looks like the following:
model <- mxModel(model, mxNormalInterval(c('A', 'C[,]', 'E[1,1]'), 0.95, 0.95))
The first argument to mxNormalInterval() is a vector of strings. These could be either matrix/algebra names or free parameter names. The second argument is the lower confidence level, and the third argument is the upper confidence level.
Is this a reasonable interface? Is there a need for asymmetric confidence levels in this interface? Should the confidence levels be expressed in units of 0-100 instead of 0-1?
The full example is present here [6].