allow symbolic indexing of vectors of observables

ext/MTKExt.jl

@@ -33,4 +33,8 @@ function SymbolicIndexingInterface.observed(sys::PartitionedGraphSystem, var::Nu
     SymbolicIndexingInterface.observed(sys, tosymbol(var; escape=false))
 end
 
+function SymbolicIndexingInterface.observed(sys::PartitionedGraphSystem, vars::Union{Vector{Num}, Tuple{Vararg{Num}}})
+    SymbolicIndexingInterface.observed(sys, tosymbol.(vars; escape=false))
+end
+
 end

src/symbolic_indexing.jl

@@ -192,6 +192,14 @@ function SymbolicIndexingInterface.is_observed(sys::PartitionedGraphSystem, sym)
     haskey(sys.compu_namemap, sym)
 end
 
+function SymbolicIndexingInterface.observed(sys::PartitionedGraphSystem, syms::Union{Vector{Symbol}, Tuple{Vararg{Symbol}}})
+    function (u, p, t)
+        map(syms) do sym
+            observed(sys, sym)(u, p, t)
+        end
+    end
+end
+
 function SymbolicIndexingInterface.observed(sys::PartitionedGraphSystem, sym)
     (; tup_index, v_index, prop, requires_inputs) = sys.compu_namemap[sym]
 

test/runtests.jl

@@ -5,3 +5,7 @@ using SafeTestsets
     solution_solve_test()
     sensitivity_test()
 end
+
+@safetestset "SII" begin
+    include("symbolic_indexing.jl")
+end

test/symbolic_indexing.jl

@@ -0,0 +1,10 @@
+include("particle_osc_example.jl")
+using SymbolicIndexingInterface
+
+@testset "Symbolic Indexing of Vectors" begin
+    sol = solve_particle_osc(x1=1.0, x2=-1.0)
+
+    a = getsym(sol, :particle1₊a)(sol)[end]
+    ω = getsym(sol, :osc₊ω₀)(sol)[end]
+    @test getsym(sol, [:osc₊ω₀, :particle1₊a])(sol)[end] == [ω, a]
+end