Special sum operator for IntersectedDenseFSA

sandbox/GNAT.jl

@@ -6,7 +6,7 @@ using InteractiveUtils
 
 # ╔═╡ 510f7d8a-ce11-11ed-2832-cdc20fa6f700
 begin
-	using Pkg; Pkg.activate("..")
+	using Pkg; Pkg.activate("./mmi")
 	using Revise
 	using FiniteStateAutomata
 	using Semirings
@@ -131,11 +131,14 @@ L
 # ╔═╡ 5ecadd35-feea-459f-9776-3a2762b0de9f
 # FSA(C)
 
-# ╔═╡ 2ea1644a-8836-443b-a1ee-8d13dbd4a534
-H[:, 2]
+# ╔═╡ 410d3e85-8946-4c74-9fd5-77c799e45277
+sum(G ∩ C) ≈ sum(FSA(G ∩ C))
 
-# ╔═╡ 68d8f4b3-48e1-49ca-b910-c65c2ec19768
-ones(K, 3) * H[:,2]'
+# ╔═╡ 895f0152-e4c6-4a1d-97e0-f4a4308fe362
+sum(FSA(G ∩ C))
+
+# ╔═╡ 584c1b63-3f12-4383-8bf0-8078e518910d
+≈
 
 # ╔═╡ Cell order:
 # ╠═510f7d8a-ce11-11ed-2832-cdc20fa6f700
@@ -163,5 +166,6 @@ ones(K, 3) * H[:,2]'
 # ╠═b2290feb-24a1-4f7d-8216-7c69ea363a67
 # ╠═5c3893f7-b64f-410f-9be2-5c2023fd9093
 # ╠═5ecadd35-feea-459f-9776-3a2762b0de9f
-# ╠═2ea1644a-8836-443b-a1ee-8d13dbd4a534
-# ╠═68d8f4b3-48e1-49ca-b910-c65c2ec19768
+# ╠═410d3e85-8946-4c74-9fd5-77c799e45277
+# ╠═895f0152-e4c6-4a1d-97e0-f4a4308fe362
+# ╠═584c1b63-3f12-4383-8bf0-8078e518910d

src/dense_fsa.jl

@@ -5,6 +5,8 @@ struct DenseFSA{K, L} <: AbstractAcyclicFSA{K, L}
     DenseFSA(H, Σ, ρ) = length(Σ) == size(H, 1) ? new{eltype(H), eltype(Σ)}(H, Σ, ρ) : error("Σ not compatible")
 end
 
+DenseFSA(H::AbstractMatrix{K}, Σ::AbstractVector) where K = DenseFSA(H, Σ, zero(K))
+
 α(G::DenseFSA) = begin
     L = length(G.Σ)
     N = size(G.H, 2)
@@ -111,3 +113,12 @@ end
 λ(I::IntersectedDenseFSA) = repeat(λ(I.B), size(I.A.H, 2) - 1)
 
 ρ(I::IntersectedDenseFSA) = ρ(I.B) * ρ(I.A)
+
+function Base.sum(I::IntersectedDenseFSA, n = size(I.A.H, 2) - 1)
+    CH = I.C' * I.A.H
+    v = CH[:, 1] .* α(I.B)
+    for n in 2:n
+        v = (T(I.B)' * v) .* CH[:, n]
+    end
+    dot(v, ω(I.B) .* CH[:, end]) + ρ(I)
+end

src/ops.jl

@@ -31,10 +31,10 @@ end
 Accumulate the weight of all the paths of length less or equal to
 `n`.
 """
-function Base.sum(A::AbstractFSA; init = α(A), n = nstates(A) + 2)
+function Base.sum(A::AbstractFSA; init = α(A), n = nstates(A))
     v = init
     σ = dot(v, ω(A)) + ρ(A)
-    for i in 2:n-1
+    for _ in 2:n
         v = T(A)' * v
         σ += dot(v, ω(A))
     end

test/runtests.jl

@@ -162,6 +162,14 @@ for K in Ks, L in Ls
             @test s1.tval[2] == s2.tval[2]
             @test typeof(AcyclicFSA(A3) |> minimize) <: AbstractAcyclicFSA
         end
+
+        @testset verbose=true "intersection" begin
+            Σ = ["a", "b", "c"]
+            H = K.randn(length(Σ), 4)
+            dfsa = DenseFSA(H, Σ)
+            @test sum(dfsa ∩ A3) ≈ sum(FSA(dfsa ∩ A3))
+            @test sum(A3 ∩ dfsa) ≈ sum(FSA(dfsa ∩ A3))
+        end
     end
 end