OpenMx Developer Forums

Currently the functions named "omx*" consist of (A) uncommon functions that we intend to remain backwards compatible in all future versions of OpenMx, and (B) uncommon functions that may be helpful to advanced OpenMx users but whose interface might change in the future. We would like to keep type (A) functions in the "omx*" category and rename type (B) functions with a new character prefix. We wish to solicit feedback on which functions should remain in the "omx*" category, and get suggestions for the new prefix string for the type (B) functions.

I started putting together a function that will generate a thresholds matrix. The implementation is attached to this post. The function omxGenerateThresholds accepts five arguments:

1. data - a data frame that has been transformed with mxFactor()
2. threshNames - a character vector of the column names. In OpenMx 1.0 must be equal to the column names of the data set.
3. threshLabels - a character vector of the free parameter names. Used to specify equality constraints.

Hi
Every time I post a something at an OpenMx forum, I get the following error message:
warning: implode(): Invalid arguments passed in /private/var/openmx/drupal-6.16/sites/all/modules/mollom/mollom.module on line 1439.
The post does get saved despite the error message. Thus, this is not a real problem for me, just want you to know.

I'm writing a helper function that takes a set of existing MxModels and returns a parent model that (a) includes them all as submodels, and (b) has an mxAlgebraObjective that sums the objectives of the existing MxModels. I have always avoided putting spaces in MxModel names when I plan to use that model in an algebra. Is it possible to refer to the objective slot in a model named "My Poorly Named Model" in an MxAlgebra? All of my usual tricks involving quotes don't work.

ryne

Hello!

Today, I felt like fixing all my free parameters and call mxRun() on my model. I expected the optimizer to converge instantly or rather not to be invoked. Instead, it seems the backend is running into an infinite loop somehow. Maybe the backend needs to check the condition of no free parameters in the model.

Here's a beta of a new function to get standardized output from a RAM model. I've only tested it on one or two models, so I'd love some help breaking it. You have to either supply a model that uses mxRAMObjective or you have to supply the names of the A and S matrices.

Edit (11/1/10): Previous version standardized S correctly but A incorrectly. Fixed. Also improved some error messages.

It looks like the R 2.12.0 binary has been released for windows. I've made some quick adjustments such that it should be possible to download a binary build of OpenMx for 32-bit windows with R 2.12.0. Our team is working on the 64-bit windows, this will be very cool when cross-compilation is working. We need to compile libnpsol for 64-bit windows so have patience.

In the OpenMx 1.1 release, the argument defvar.row has been added to the mxEval function. This argument can specify which row number to use when populating definition variables. It is applied only when compute=TRUE in a call to mxEval. The row number uses the R convention of 1-based indexing (ie. the rows are numbered 1, 2, 3, etc.).

The mxErrorPool() is a function that allows the user to retrieve a model that has been executed and returned with an error. If mxRun() throws an error, then no model is returned to the user. This has the advantage of strongly reminding the user that the result of the optimization is very likely incorrect. However, this behavior is discouraging when debugging a model. One alternative is to use mxRun(unsafe=TRUE) that will convert any errors into warnings.