OpenMx Developer Forums

The summary() function has a optional parameter 'numObs = X' that adjusts the number of observations to 'X' for the purposes of calculating summary statistics. I'm in the process of adding an argument 'numObs = X' to the mxAlgebraObjective() function that will increment the total number of observations in the model by 'X' for the purposes of calculating summary statistics.

Question: do we need a similar knob for the number of observed statistics in the summary() function and in the mxAlgebraObjective() function?

Here is a proposed change to the mxRun() command. I've noticed that we have a tendency of adding flags to 'mxRun' as time marches forward. Currently, the signature for 'mxRun' is something like:

mxRun(model, flag1 = value1, flag2 = value2, flag3 = etc.).

The proposal is to change the signature to:

mxRun(model, ..., flag1 = value1, flag2 = value2, flag3 = etc.)

The OpenMx style guide says:
The first useful trick is entering the string model$ in the R interpreter and then pressing the TAB key. You should see a list of all the named entities contained within the model object

I enterd the prior script to define model, but, alas, when I enter:
model$
and press Tab
absolutely nothing happens.
I have a bog standard PC and am using R via the Gui.

Thought I must be doing something stupid and tried several times but no joy.

At today's developers meeting, the OpenMx 1.0 feature set was discussed. First, a wishlist of features was compiled. From the wishlist a subset of features was selected for the 1.0 release. Our target for implementing these features is May 13th. When we have reached the goal of implementing these features, a 0.9 release will be created. At which point, there will be a feature freeze from the 0.9 to 1.0 release. Performance improvements may occur between the 0.9 to 1.0 releases. The month of June is the goal for the 1.0 release.

The wishlist:

I noticed that you are modifying OpenMx to disallow forbidden characters in names or labels: "+-!~?:*/^%<>=&|$"
Just to say that this will have implications for some of the demonstration scripts. I have not checked them all, but the model on p 31 of the OpenMx documentation has a model name that won't work, and I have also found cases in demo files where the objective has the name "-2LL".

For beginners used to other programming languages, the fact that a syntax error does not terminate operation of a script is confusing.

Tim and I were discussing my recent botched growth mixture code, and have a proposal for a future version of mixture modeling which should be a little bit easier on the user. It consists of two parts:

At the end of the last developers meeting, it was tentatively agreed that we should discuss the feature set for the OpenMx 1.0 release. I propose to make that issue the primary topic for the next developers meeting, on 3/19/10. Of course if something critical comes up this week, we can push the topic forward a week. Logistically, we should have this conversation soon as we are planning a June date for the OpenMx 1.0 release.

Developers: remind ourselves of the feature set promised in the grant. High probability these features will have greatest priority.

Sorry - just realised that an earlier correction I suggested to the manual was in error.
I had not realised that %x% was the way of indicating Kronecker product, and so had thought it was a typo for %*%

Would be good to add a comment to the script where this first appears to clarify.

I've written a bit for my simplified manual for beginners (see Wiki) to try and explain to the uninitiated how standard errors are estimated. My own understanding of this topic is primitive and probably wrong, so I want to run this pass the experts before incorporating it in the SMB. It's very short: could somebody who understands these things please take a look and tell me what needs changing. Thanks

• Mike Wilde progress on swift apply in R
  - create *apply() analogs for swift, in similar style to snow package
  - eventually create a swift package in R, or contribute to the snow package

• Steve: short cut in mxFIMLObjectiveFunction() using means = 0 as a shortcut for vector of zeros with free=TRUE.
• as a first step for easy thresholds write a function that takes an ordinal data input and returns a thresholds matrix
• fetch from the back-burner the project to pretty-print a OpenMx object as a script
• create a CRAN package from the twins workshop