Behavioral Genetics Models

Hi,

I don't know if I'm missing something basic here, but how does one apply constraints on means and variances across more than 2 groups (mxConstraint only accepts 2 arguments) in a saturated model, ie across sex and zygosity groups?

My data is setup such:

mzfData <- subset(twinsib.wide, ZygosityNumber ==1, selVars)
mzmData <- subset(twinsib.wide, ZygosityNumber ==2, selVars)
dzfData <- subset(twinsib.wide, ZygosityNumber ==3, selVars)
dzmData <- subset(twinsib.wide, ZygosityNumber ==4, selVars)
dzfmData <- subset(twinsib.wide, ZygosityNumber ==5, selVars)

Do scripts exist for this? I can only find common pathway models for continuous data, such as the one available at the Mx Scripts LIbrary at http://www.psy.vu.nl/mxbib/index.php?page=mx_tree&tree_list=1,2,21,23,291&last=291

Thanks,

Scott

Hi Everyone,

I'm still rather green with all of this, but am learning a lot. I've tried to adapt a script to work with right and left eye data for the simple case of a single variable (axial length of the eye) and was wondering if someone would be kind enough to run it and comment on what I've done.

I've attached the script and the data (change .txt to .RData - it'd be nice if we could upload RData files directly).

There are 4 main queries which I've marked in the text with a ? in large lettering, so hopefully it'll be easy to find.

Hi all,

I'm fitting a univariate threshold model on binary data and it appears to work well (see below for the script), except that in the summary I get either very small or NaN standard errors, like this:

name matrix row col Estimate Std.Error
1 ab11 ACE.aboys 1 1 0.5690466 2.121996e-314
2 cb11 ACE.cboys 1 1 0.7157107 6.365987e-314
3 eb11 ACE.eboys 1 1 0.4049003 NaN
4 ag11 ACE.agirls 1 1 0.2620615 NaN
5 cg11 ACE.cgirls 1 1 0.8921872 NaN
6 eg11 ACE.egirls 1 1 0.3678666 1.060998e-313

Hi,

I have a couple of queries relating to means modelling but more on the conceptual side rather than OpenMx scripting.

Hi all,

I'm trying to fit a saturated model to my data (1 binary variable, 5 zygosity groups), and want to estimate 10 thresholds (one for each twin in all zyg groups), and 5 twin correlations (1 per zyg group). The model runs, the right number of parameters are estimated and the estimations look good, but the number of observed statistics is 0, so I get a negative number of degrees of freedom... There are no error messages, and I've looked into different parts of the model, but can't find where it goes wrong. I hope you can help me with this, thanks in advance!

Lot Geels

Hi,

I'm unfamiliar with Mx and am still learning SEM concepts - apologies if I'm missing something fundamental with the following.

I've tried adapting a script (one of Hermines) used in the recent twins course for comparing means and variances for a multivariate trait across right and left eyes.

I thought commenting out the 4 MxAlgebra functions across twin order and zygosity would allow me to compare grand means and variances across R and L, but I receive an error message saying that an argument is missing.

Can someone tell me where I'm going wrong?

Thanks heaps,

in the thread "matrix redimensioning" tim bates mentioned the "genEpi_ library." can we users get information about this?

greg

I am running the script: MultivariateTwinAnalysis_MatrixRaw.R from the TC24 homepage, on my own data.
I don't seem to be able to create any saturated output from the following commands, although the multiTwinSatFit is not empty:
parameterSpecifications(multiTwinSatFit)
expectedMeansCovariances(multiTwinSatFit)
tableFitStatistics(multiTwinSatFit)

I get the following error messages:
Error: could not find function "parameterSpecifications"
Error: could not find function "expectedMeansCovariances"
Error: could not find function "tableFitStatistics"

Hi,
Getting my head around how to add a covariate to a script.
In mx1.x, there were two 'data' statements: "SElect" and "DEfinition_variables".

Select is equivalent to mxData() and selects the variables from which expected covariances (and means) are computed.