JuliaPOMDP/DESPOT.jl

testing for action == -1

Opened this issue · 2 comments

zsunberg commented

There is some code in DESPOT.jl that checks for action == -1 to decide what to do next. I am assuming that this is indicating some sort of exceptional circumstance. This is problematic for a couple reasons (I'm sure these have been considered but just haven't been fixed yet).

  1. There could be problems for which -1 is a valid action, and
  2. if the actions are not integers, there could be type stability issues.

We should fix this eventually, perhaps by having the functions return a Nullable{A}.

zsunberg commented

Or maybe this is fine? maybe in these cases the action is not an actual action from the problem, but maybe just an integer representing the aciton.

ebalaban commented

I presume you are referring to src/nodes.jl, line 202? That's a vestige of my very first implementation of DESPOT, where actions where mapped to integer indices (shows that I have not really looked at pruning since then ;-)). Yes, this should really be handled with Nullable or something of the sort.