added LeafBelief so that you can get the state at a leaf node (#23)

Project.toml

@@ -1,7 +1,7 @@
 name = "BasicPOMCP"
 uuid = "d721219e-3fc6-5570-a8ef-e5402f47c49e"
 repo = "https://github.com/JuliaPOMDP/BasicPOMCP.jl"
-version = "0.3.4"
+version = "0.3.5"
 
 [deps]
 BeliefUpdaters = "8bb6e9a1-7d73-552c-a44a-e5dc5634aac4"

notebooks/Minimal_Example.ipynb

@@ -264,7 +264,7 @@
     }
    ],
    "source": [
-    "filter = SIRParticleFilter(pomdp, 1000)\n",
+    "filter = BootstrapFilter(pomdp, 1000)\n",
     "for (s,a,r,sp,o) in stepthrough(pomdp, planner, filter, \"s,a,r,sp,o\")\n",
     "    @show (s,a,r,sp,o)\n",
     "end"

src/BasicPOMCP.jl

@@ -45,7 +45,7 @@ export
     default_action,
 
     BeliefNode,
-    AOHistoryBelief,
+    LeafNodeBelief,
     AbstractPOMCPSolver,
 
     PORollout,
@@ -55,7 +55,10 @@ export
 
     D3Tree,
     node_tag,
-    tooltip_tag
+    tooltip_tag,
+
+    # deprecated
+    AOHistoryBelief
 
 abstract type AbstractPOMCPSolver <: Solver end
 
@@ -147,14 +150,37 @@ function POMCPTree(pomdp::POMDP, b, sz::Int=1000)
                          )
 end
 
-struct AOHistoryBelief{H<:NTuple{<:Any, <:NamedTuple{(:a, :o)}}}
+struct LeafNodeBelief{H, S} <: AbstractParticleBelief{S}
     hist::H
+    sp::S
+end
+POMDPs.currentobs(h::LeafNodeBelief) = h.hist[end].o
+POMDPs.history(h::LeafNodeBelief) = h.hist
+
+# particle belief interface
+ParticleFilters.n_particles(b::LeafNodeBelief) = 1
+ParticleFilters.particles(b::LeafNodeBelief) = (b.sp,)
+ParticleFilters.weights(b::LeafNodeBelief) = (1.0,)
+ParticleFilters.weighted_particles(b::LeafNodeBelief) = (b.sp=>1.0,)
+ParticleFilters.weight_sum(b::LeafNodeBelief) = 1.0
+ParticleFilters.weight(b::LeafNodeBelief, i) = i == 1 ? 1.0 : 0.0
+
+function ParticleFilters.particle(b::LeafNodeBelief, i)
+    @assert i == 1
+    return b.sp
 end
-POMDPs.currentobs(h::AOHistoryBelief) = h.hist[end].o
-POMDPs.history(h::AOHistoryBelief) = h.hist
 
-function insert_obs_node!(t::POMCPTree, pomdp::POMDP, ha::Int, o)
-    acts = actions(pomdp, AOHistoryBelief(tuple((a=t.a_labels[ha], o=o))))
+POMDPs.mean(b::LeafNodeBelief) = b.sp
+POMDPs.mode(b::LeafNodeBelief) = b.sp
+POMDPs.support(b::LeafNodeBelief) = (b.sp,)
+POMDPs.pdf(b::LeafNodeBelief{<:Any, S}, s::S) where S = float(s == b.sp)
+POMDPs.rand(rng::AbstractRNG, s::Random.SamplerTrivial{<:LeafNodeBelief}) = s[].sp
+
+# old deprecated name
+const AOHistoryBelief = LeafNodeBelief
+
+function insert_obs_node!(t::POMCPTree, pomdp::POMDP, ha::Int, sp, o)
+    acts = actions(pomdp, LeafNodeBelief(tuple((a=t.a_labels[ha], o=o)), sp))
     push!(t.total_n, 0)
     push!(t.children, sizehint!(Int[], length(acts)))
     push!(t.o_labels, o)

src/solver.jl

@@ -91,7 +91,7 @@ function simulate(p::POMCPPlanner, s, hnode::POMCPObsNode, steps::Int)
 
     hao = get(t.o_lookup, (ha, o), 0)
     if hao == 0
-        hao = insert_obs_node!(t, p.problem, ha, o)
+        hao = insert_obs_node!(t, p.problem, ha, sp, o)
         v = estimate_value(p.solved_estimator,
                            p.problem,
                            sp,

test/runtests.jl

@@ -9,6 +9,7 @@ using POMDPSimulators
 using POMDPModelTools
 using POMDPTesting
 using POMDPLinter: @requirements_info, @show_requirements, requirements_info
+using ParticleFilters: n_particles, particles, particle, weights, weighted_particles, weight_sum, weight
 
 import POMDPs:
 	transition,
@@ -24,7 +25,7 @@ import POMDPs:
 struct ConstObsPOMDP <: POMDP{Bool, Symbol, Bool} end
 updater(problem::ConstObsPOMDP) = DiscreteUpdater(problem)
 initialstate(::ConstObsPOMDP) = BoolDistribution(0.0)
-transition(p::ConstObsPOMDP, s::Bool, a::Symbol) = BoolDistribution(0.5)
+transition(p::ConstObsPOMDP, s::Bool, a::Symbol) = BoolDistribution(0.0)
 observation(p::ConstObsPOMDP, a::Symbol, sp::Bool) = BoolDistribution(1.0)
 reward(p::ConstObsPOMDP, s::Bool, a::Symbol, sp::Bool) = 1.
 discount(p::ConstObsPOMDP) = 0.9
@@ -50,10 +51,26 @@ end;
 
 @testset "belief dependent actions" begin
 	pomdp = ConstObsPOMDP()
-	function POMDPs.actions(m::ConstObsPOMDP, b::AOHistoryBelief)
+	function POMDPs.actions(m::ConstObsPOMDP, b::LeafNodeBelief)
 		@test currentobs(b) == true
         @test history(b)[end].o == true
         @test history(b)[end].a == :the_only_action
+        @test mean(b) == 0.0
+        @test mode(b) == 0.0
+        @test only(support(b)) == false
+        @test pdf(b, false) == 1.0
+        @test pdf(b, true) == 0.0
+        @test rand(b) == false
+        @test n_particles(b) == 1
+        @test only(particles(b)) == false
+        @test only(weights(b)) == 1.0
+        @test only(weighted_particles(b)) == (false => 1.0)
+        @test weight_sum(b) == 1.0
+        @test weight(b, 1) == 1.0 
+        @test particle(b, 1) == false
+
+        # old type name - this can be removed when upgrading versions
+        @test b isa AOHistoryBelief
         return actions(m)
 	end