Convergence / latest version of Stan issues with our covid-19 model?

[mike-lawrence]

@mike-lawrence

I think I also see opportunities to use the performance trick posted here . I’ll start working on that now and let you know if I have any success with a pull request.

FYI, I discovered I’d been reading the model incorrectly (I’d had the covariate matrices transposed in my head) and there’s far less opportunity for this trick to make a difference than I thought, at least with the simple approach from that case study example. There’s still a lot of redundancy in that for a given covariate and country, there’s only a couple unique values being multiplied by that covariate’s alpha, and I’ve begun to think about approaches to eliminating that redundancy as well, but it’ll take me a while to work out something general/flexible.