Compatibility with Alg4dm book

[zsunberg]

I have been noticing that many of my students are translating between the MDP struct in algorithmsbook.com and POMDPs.jl. We should automate this. I think we should make a new package called AlgorithmsBook.jl or similar that provides a convert(AlgorithmsBook.MDP, ::POMDPs.MDP) and vice versa.

@mykelk @tawheeler any thoughts about this? Do you have a repo of code that was used to test the algorithms in the book? That might be useful for developing this package.

[mykelk]

Great idea! We haven't made the code available in a repo yet; we've been so focused on getting the book content in shape. In addition to @tawheeler , I think @mossr might have some thoughts.

[tawheeler]

Oh interesting. The MDP / POMDP representation in the book is decidedly less efficient than what one typically wants to use "for real" with POMDPs.jl. We could certainly provide a translation though. For example, we don't template on state / action types, and sometimes just leave some fields as "nothing" when they aren't used.

struct MDP
    γ  # discount factor
    𝒮  # state space
    𝒜  # action space
    T  # transition function
    R  # reward function
    TR # sample transition and reward
end

It should be pretty straightforward to support the translation you suggest.

[mossr]

I'm all for this! There's talk about turning alg4dm into its own Julia package, so this would be useful to do alongside that work.