value does not work if called before action

[zsunberg]

This happens because value checks if the tree is not nothing in

MCTS.jl/src/vanilla.jl

Line 208 in 47b8681

if planner.tree == nothing

. Currently it is an empty tree, so it does not plan

julia> sol3 = solve(s3, m)

julia> value(sol3, states[4])
ERROR: State 0.06060606060606082 not present in MCTS tree.
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:33
 [2] value(tr::MCTS.MCTSTree{Float64, Float64}, s::Float64)
   @ MCTS ~/.julia/dev/MCTS/src/vanilla.jl:217
 [3] value(planner::MCTSPlanner{QuickMDP{UUID("20287054-e7ba-4231-98f4-917124d65b0b"), Float64, Float64, NamedTuple{(:stateindex, :isterminal, :actionindex, :transition, :reward, :states, :actions, :discount), Tuple{Dict{Float64, Int64}, Bool, Dict{Float64, Int64}, var"#12#14", var"#13#15", StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}, typeof(valid_actions), Float64}}}, Float64, Float64, MCTS.SolvedRolloutEstimator{POMDPPolicies.RandomPolicy{Random._GLOBAL_RNG, QuickMDP{UUID("20287054-e7ba-4231-98f4-917124d65b0b"), Float64, Float64, NamedTuple{(:stateindex, :isterminal, :actionindex, :transition, :reward, :states, :actions, :discount), Tuple{Dict{Float64, Int64}, Bool, Dict{Float64, Int64}, var"#12#14", var"#13#15", StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}, typeof(valid_actions), Float64}}}, BeliefUpdaters.NothingUpdater}, Random._GLOBAL_RNG}, Random._GLOBAL_RNG}, s::Float64)
   @ MCTS ~/.julia/dev/MCTS/src/vanilla.jl:211
 [4] top-level scope
   @ REPL[61]:1