[ADMB Users] matrix not positive definite

Mollie Brooks mbrooks at ufl.edu
Mon Feb 11 10:54:02 PST 2013


It seems that the problem came from not initializing the variance-covariance matrix. I wrongly assumed that it wasn't an issue because the calculations were correct in some rounds of optimization.

thanks,
Mollie

Mollie Brooks
Postdoctoral Researcher, Ponciano Lab
Biology Department, University of Florida
http://people.biology.ufl.edu/mbrooks


On 10 Feb 2013, at 1:39 PM, Mollie Brooks wrote:

> Thanks for the response.
> 
> I'm attaching the code and a tiny simulated data set. I can send a larger simulated dataset if it helps. I also attached the R code I used to simulate the data. 
> 
> The attached pdf contains the formula for the variance covariance matrix as "Process Error". The "Predictions" are temporally autocorrelated latent variables that determine the Bernoulli process of whether or not there is water in the pond.
> thanks,
> Mollie
> <pond_sep.tpl><pond_sep.pin><pond_sim.dat><simulate.R>
> <essential_formulas.pdf>
> 
> Mollie Brooks
> Postdoctoral Researcher, Ponciano Lab
> Biology Department, University of Florida
> http://people.biology.ufl.edu/mbrooks
> 
> 
> On 10 Feb 2013, at 11:54 AM, dave fournier wrote:
> 
>> Hard to say much that isn't probably wrong without seeing your code etc.
>> _______________________________________________
>> Users mailing list
>> Users at admb-project.org
>> http://lists.admb-project.org/mailman/listinfo/users
>> 
> 
> _______________________________________________
> Users mailing list
> Users at admb-project.org
> http://lists.admb-project.org/mailman/listinfo/users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.admb-project.org/pipermail/users/attachments/20130211/d0f0b048/attachment.html>


More information about the Users mailing list