Aki Vehtari

Results 305 comments of Aki Vehtari

Could you 1) give a pointer to an example in `brms`, 2) include an example code how you would use it in `loo`, 2) and tell what is the case...

1. Thanks for the examples. I've never used `future`, so these were helpful to understand. 2. If `model` is `brms` model then this might be a `brms` package issue instead...

> To be clear, I would be able to run loo on a subsample of folds and still get a good approximation, but this is not yet implemented, right? Probably...

> Should we avoid NAs and return always Inf and NaN here? I would prefer khat=Inf when the failure is due to extremely long tail. At least in the cases...

Thinking for a moment, I think normalized densities would make more sense, and if someone would like to use normalized quadrature weights it's easier to obtain them from normalized densities...

I have tested. When using sample sizes that are typical gpd_fit use and when tail thicknesses are in the interesting region (

Thanks to a question by @sethaxen, I realized that what is above named as densities are not yet densities. Originally, the algorithm computes quadrature weights and for those most natural...

Here is an illustration ![image](https://user-images.githubusercontent.com/6705400/149550639-746622c6-f34b-495e-b17c-c220b583e577.png) The yellow contours present the likelihood, the red dashed contours present the posterior, blue line is the profile line, the blue dots present the quadrature...

> I see; does that hold even though the samples aren't IID? That would also tend to make the posterior too narrow. True. I don't think this is an issue...

Sorry, this has been left hanging for such a long time. After considering, I think we shouldn't change the existing output variable names (ie k -> k_hat, sigma -> sigma_hat),...