Re: [R-sig-phylo] Unsual values of alpha in OU models

2015-04-12 Thread Diego Salazar Tortosa
Thank you all for your responses, they have been of great use. First, I have not rescaled the tree, thus alpha values ​​are really rare and they indicate a rate adaption very fast. For the selection of models I have used AICc and then I have analysed the reliability of the parameters with a

Re: [R-sig-phylo] Unsual values of alpha in OU models

2015-03-27 Thread Aaron King
In many situations, the OU model parameter alpha is not well identified. This has been pointed out before, but it's quite common for the parameter values (and not just alpha, though that's typically the worst) to be poorly identified, even if the model selection is unambiguous. OU model

Re: [R-sig-phylo] Unsual values of alpha in OU models

2015-03-27 Thread Diego Salazar Tortosa
Thank you for your answer Aaron. Clear to me that this situation is common in the OU models, but I don't know what criteria I should use when select between different OU models, AICc or reliability of parameters? Thanks in advance Regards Diego Salazar 2015-03-27 11:08 GMT+00:00 Aaron King

Re: [R-sig-phylo] Unsual values of alpha in OU models

2015-03-27 Thread Brian O'Meara
You can select between models using AICc, but then you can look at the reliability, more robustly than using eigenvalues, by using OUwie.boot() to do parametric bootstrapping. Another very useful thing done by Hansen, Bartoszek, and colleagues is to do a contour plot around the maximum likelihood