Login

News

Behavioral Genetics Models

Posted on
No user picture. IvanVoronin Joined: 08/18/2013

Equality constraints in saturated model

Forums
Behavioral Genetics Models
What is the better way to introduce the constrains given that the constrained elements are computed, not defined as matrices?
Posted on
No user picture. szellers Joined: 04/04/2018

Diagnostics for Confidence Intervals

Forums
Behavioral Genetics Models
I am estimating a linear latent growth model using two twin samples and I am also estimating a common pathway model in the same samples. The latent slope and intercept are free to correlate with each other and with the latent factor from the common path model. I am trying to compute confidence intervals using mxCI and I am getting errors. When I use the verbose summary, I get the diagnostic and status code of "alpha level not reached iteration limit/blue" on many of my estimates. I've looked around at some documentation/other forum posts.
Posted on
No user picture. JuanJMV Joined: 07/20/2016

Common and independent models

Forums
Behavioral Genetics Models
Hello,

I am trying to fit a trivariate model with 3 continuous variables. I am also trying to fit the independent and common pathways models but I do not know if my script is correct.

My models have:
ADE: 27 parameters
Independent pathway model: 27 parameters
Common pathway model: 24 parameters

I think that number of parameters is correct but I am not sure. Also, I have negative values (for example dl_1_1, fl_2_1) and I do not know if it is correct.

Posted on
No user picture. Kelsey Joined: 01/31/2017

Bivariate model with binary and continuous variable

Forums
Behavioral Genetics Models
Hi,
I am new to bivariate models and I have tried to adapt the twoACEj.R script by Hermine Maes from an ordinal to a binary variable in the below script. The script runs without errors, but my first question is whether my adaptations are correct?

Posted on
No user picture. JuanJMV Joined: 07/20/2016

phenotypic correlation

Forums
Behavioral Genetics Models
Hello,

I am a little bit confused about how to calculate the phenotypic correlation between variable 1 and variable 2, in a bivariate model with one binary variable and one continuous variable.

I mean if I use this: mxEval(cov2cor(V), fitADE, T). I get a value of 0.200 whereas if I calculate the correlation in SPSS (also in R) I get a value of 0.150.

I do not know if I am doing something wrong. Should the results be the same right?
I have tried with different methods, with and without covariables etc… But I get the same value.

Posted on
Picture of user. Julia Joined: 03/29/2012

System is exactly singular

Forums
Behavioral Genetics Models
Hi all,

I am running a trivariate Cholesky ADE model with one binary and two continuous variables. As profile-based confidence intervals took more than 24h to run and a lot of them were missing I decided to try bootstrapping. I ran mxBootstrap with 1000 replicates to get 95% CI and all looked fine except CI's for dominant genetic correlation rD. I get the following error:

Posted on
No user picture. JuanJMV Joined: 07/20/2016

Siblings

Forums
Behavioral Genetics Models
Hello,

I am trying to do a univariate analysis with a binary variable. I am not sure how to treat siblings
I have created different groups MZ, DZ, SIB (which I think is the same as introduce SIB in the DZ group).

I have also checked if DZ and SIB can be equated through the saturated model and there are not significant differences when I equated means and variances between DZ and Sib

Posted on
No user picture. szellers Joined: 04/04/2018

Standardizing factor loadings

Forums
Behavioral Genetics Models
I am working with a common path model and I am having difficulty standardizing my factor loadings. In the past, I have identified the model by constraining the variance of the latent phenotype to 1, then I standardize factor loadings by using a matrix of standard deviations (SDs on diagonal, 0s on off-diagonal) and multiplying that by the matrix of the unstandardized factor loadings (I can attach code for this if necessary)

Posted on
Picture of user. Julia Joined: 03/29/2012

Bootstrap CI's for algebras

Forums
Behavioral Genetics Models
Hi.

Is it possible to get bootstrap confidence intervals for algebras? I am running a trivariate CHolesky decomposition model on binary variables and estimating CI's through mxCI takes more than 24h. When I ran mxBoostrap, I got CI's only for model parameters, but not for algebras. Is there a way to specify it? Or is there a way to reduce the time to running a model with intervals=T?

Thank you in advance!
Julia

Posted on
Picture of user. gary.marks@acu… Joined: 07/14/2016

Multivariate Independent Pathway with Multiple Occasions

Forums
Behavioral Genetics Models
I have been analyzing achievement/cognitive test data from the NLSY79 Children data set. I have constructed sibling-cousin pairs for each of the five tests (PPVT, digit memory, reading comprehension, reading recognition and math) at 5 occasions (ages 5-6, 7-8, 9-10, 11-12 &13-15). I have successfully run a independent pathway model for domain scores averaged over occasions (zero to 4) and 5 separate models for each age. However, there are several reasons why a combined model using all the data is more desirable than running separate scripts for each.

Subscribe to Behavioral Genetics Models
  Login

News