Introduction In indoor sport climbing different routes to the top of the wall are put up by different route setters who are also given the task of awarding each climb a ‘grade’.

Introduction I recently wanted to port some python code to c++ (latency reasons) and I quickly realised it was not going to be a trivial port. It required some template metaprogramming trickery and in the process I found myself writing my first c++ concept 1.

Count data is commonly modelled using a generalised linear model with a Poisson likelihood, and this approach extends trivially to cases with multiple count data random variables, $Z_i\in {\mathbb{Z}}^{0+},i=1\dots N$ which are indepedent of one another, $Z_i\perp Z_j,\mathrm{\forall }i,j$ because the likelihoods factor out nicely.