Published on *OpenMx* (http://openmx.psyc.virginia.edu)

By *carey*

Created *11/30/2009 - 22:31*

Mon, 11/30/2009 - 22:31 — carey [1]

is there internal documentation on the effects of mxOptions and resultant quantities in the @output slots of an MxModel object?

specific problem involves the elements of ...@output$hessianCholesky and ...@output$hessian. for the simple problem i outlined in "summary(mxRun(myMxModel)) gives strange results" i get identical results using all mxOptions defaults and using

this <- mxOption(this, "Hessian", "No"). that is, both ...@output$hessianCholesky and ...@output$hessian give identical results.

there could be a very good reason for this, but on the other hand, it could reflect a bug/documentation error. specifically, does ...@output$hessianCholesky contain a Cholesky factorization of a numerically-differentiated estimate of the Hessian or does it contain the most recent update from, say, a BFGS algorithm? similarly, is ...@output$hessian the estimate from updated Cholesky factors or is it the result of a direct call to numerically estimate the Hessian?

**Links:**

[1] http://openmx.psyc.virginia.edu/users/carey

[2] http://openmx.psyc.virginia.edu/thread/301

[3] http://openmx.psyc.virginia.edu/thread/282

[4] http://openmx.psyc.virginia.edu/forums/opensem-forums/suggestion-box