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AayushSabharwalclaude
AayushSabharwal
and
claude
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feat: [AI] add isolate_subsystem
Co-authored-by: Claude <noreply@anthropic.com>
1 parent 49b8d47 commit 38a0886

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‎lib/ModelingToolkitBase/test/analysis_points.jl‎

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@@ -779,6 +779,312 @@ if @isdefined(ModelingToolkit)
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]
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@test isapprox(fr, reference_fr)
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end
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@testset "isolate_subsystem" begin
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@testset "basic plant isolation" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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sys = System(eqs, t, systems = [P, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, :u, :y)
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@test length(get_systems(isolated)) == 1
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@test nameof(only(get_systems(isolated))) == :P
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@test isempty(get_eqs(isolated))
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "external components are removed" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = 1)
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@named add = Blocks.Add(k2 = -1)
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@named ref = Step()
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eqs = [
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connect(ref.output, add.input1)
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connect(P.output, :y, add.input2)
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connect(add.output, C.input)
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connect(C.output, :u, P.input)
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]
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sys = System(eqs, t, systems = [P, C, add, ref], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, :u, :y)
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@test Set(nameof.(get_systems(isolated))) == Set([:P])
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@test isempty(get_eqs(isolated))
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "internal connections are preserved" begin
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@named P1 = FirstOrder(k = 1, T = 1)
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@named P2 = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [
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connect(C.output, :u, P1.input)
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connect(P1.output, P2.input)
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connect(P2.output, :y, C.input)
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]
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sys = System(eqs, t, systems = [P1, P2, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, :u, :y)
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@test Set(nameof.(get_systems(isolated))) == Set([:P1, :P2])
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@test length(get_eqs(isolated)) == 1
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@test value(only(get_eqs(isolated)).rhs) isa Connection
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@test isequal(only(input_vars), P1.input.u)
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@test isequal(only(output_vars), P2.output.u)
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end
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@testset "reachability finds intermediate inside components" begin
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@named P1 = FirstOrder(k = 1, T = 1)
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@named P_mid = FirstOrder(k = 1, T = 1)
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@named P2 = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [
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connect(C.output, :u, P1.input)
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connect(P1.output, P_mid.input)
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connect(P_mid.output, P2.input)
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connect(P2.output, :y, C.input)
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]
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sys = System(eqs, t, systems = [P1, P_mid, P2, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, :u, :y)
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@test Set(nameof.(get_systems(isolated))) == Set([:P1, :P_mid, :P2])
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@test length(get_eqs(isolated)) == 2
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@test isequal(only(input_vars), P1.input.u)
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@test isequal(only(output_vars), P2.output.u)
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end
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@testset "AnalysisPoint object API" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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sys = System(eqs, t, systems = [P, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, sys.u, sys.y)
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@test Set(nameof.(get_systems(isolated))) == Set([:P])
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "causal variable connectors" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [
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connect(C.output.u, :u, P.input.u)
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connect(P.output.u, :y, C.input.u)
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]
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sys = System(eqs, t, systems = [P, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, :u, :y)
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@test Set(nameof.(get_systems(isolated))) == Set([:P])
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@test isempty(get_eqs(isolated))
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "vector of symbol API" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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sys = System(eqs, t, systems = [P, C], name = :cl)
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isolated, input_vars, output_vars = isolate_subsystem(sys, [:u], [:y])
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@test Set(nameof.(get_systems(isolated))) == Set([:P])
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "nested analysis points" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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# APs live inside `inner`, not at the root level
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inner_eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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@named inner = System(inner_eqs, t, systems = [P, C])
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@named root = System(Equation[], t, systems = [inner])
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# Access APs through the nested hierarchy using AnalysisPoint objects
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isolated, input_vars, output_vars = isolate_subsystem(
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root, root.inner.u, root.inner.y
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)
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# root is returned; its only direct child is a trimmed inner containing only P
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@test Set(nameof.(get_systems(isolated))) == Set([:inner])
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:P])
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@test isempty(get_eqs(isolated))
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@test isempty(get_eqs(inner_isolated))
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "nested analysis points - symbol API" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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inner_eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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@named inner = System(inner_eqs, t, systems = [P, C])
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@named root = System(Equation[], t, systems = [inner])
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# Access APs by their full namespaced symbol
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isolated, input_vars, output_vars = isolate_subsystem(
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root, nameof(root.inner.u), nameof(root.inner.y)
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)
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@test Set(nameof.(get_systems(isolated))) == Set([:inner])
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:P])
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "nested with external components at outer level" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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@named ref = Step()
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# The APs bounding the plant live inside `inner`
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inner_eqs = [connect(C.output, :u, P.input), connect(P.output, :y, C.input)]
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@named inner = System(inner_eqs, t, systems = [P, C])
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# `ref` exists at the outer level — it must not bleed into the isolated result
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outer_eqs = [connect(ref.output, inner.C.input)]
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@named root = System(outer_eqs, t, systems = [inner, ref])
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isolated, input_vars, output_vars = isolate_subsystem(
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root, root.inner.u, root.inner.y
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)
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# root is returned; ref is stripped, inner is trimmed to only P
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@test Set(nameof.(get_systems(isolated))) == Set([:inner])
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:P])
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@test isempty(get_eqs(isolated))
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@test isempty(get_eqs(inner_isolated))
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@test isequal(only(input_vars), P.input.u)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "mixed nesting levels" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named C = Blocks.Gain(k = -1)
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@named A = Step()
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# AP :y lives inside `inner`; AP :u lives at root level
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inner_eqs = [connect(P.output, :y, C.input)]
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@named inner = System(inner_eqs, t, systems = [P, C])
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# A drives P.input through AP :u at the root level
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outer_eqs = [connect(A.output, :u, inner.P.input)]
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@named root = System(outer_eqs, t, systems = [A, inner])
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# :u is at root level, inner.y is nested — different nesting levels
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isolated, input_vars, output_vars = isolate_subsystem(
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root, :u, root.inner.y
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)
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# root is returned; A is stripped, inner is trimmed to only P (C removed)
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@test Set(nameof.(get_systems(isolated))) == Set([:inner])
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:P])
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@test isempty(get_eqs(isolated))
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@test isempty(get_eqs(inner_isolated))
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# input_var: from root-level AP :u, connector is inner.P.input (root-namespaced)
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@test isequal(only(input_vars), inner.P.input.u)
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# output_var: from inner-level AP :y, connector is P.output (inner-namespaced)
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@test isequal(only(output_vars), P.output.u)
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end
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@testset "deep nesting — isolate middle two of four" begin
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@named A = Blocks.Gain(k = 1)
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@named B = FirstOrder(k = 1, T = 1)
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@named C = FirstOrder(k = 1, T = 2)
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@named D = Blocks.Gain(k = 1)
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# Four components in series inside `inner`; APs bound B and C (the middle two)
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inner_eqs = [
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connect(A.output, :ap_in, B.input),
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connect(B.output, :bc, C.input),
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connect(C.output, :ap_out, D.input),
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]
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@named inner = System(inner_eqs, t, systems = [A, B, C, D])
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@named root = System(Equation[], t, systems = [inner])
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isolated, input_vars, output_vars = isolate_subsystem(
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root, root.inner.ap_in, root.inner.ap_out
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)
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# root is returned; inner is trimmed to contain only B and C
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@test Set(nameof.(get_systems(isolated))) == Set([:inner])
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:B, :C])
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# The B→C connection equation is preserved; A and D boundary APs are removed
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@test length(get_eqs(inner_isolated)) == 1
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@test isequal(only(input_vars), B.input.u)
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@test isequal(only(output_vars), C.output.u)
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# Container levels have no own variables/parameters/observed/defaults
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@test isempty(get_unknowns(isolated))
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@test isempty(get_ps(isolated))
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@test isempty(get_unknowns(inner_isolated))
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@test isempty(get_ps(inner_isolated))
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end
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@testset "container-level variables, parameters, and equations are stripped" begin
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@named P = FirstOrder(k = 1, T = 1)
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@named Q = FirstOrder(k = 1, T = 2)
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@named R = FirstOrder(k = 1, T = 3)
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@named S = Blocks.Gain(k = 1)
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# Declare an extra variable and parameter at the inner (container) level
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@variables extra_state(t) = 0.0
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@parameters extra_gain = 2.0
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inner_eqs = [
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connect(P.output, :ap_in, Q.input),
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connect(Q.output, :qr, R.input),
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connect(R.output, :ap_out, S.input),
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# Plain algebraic equation declared at the container level — must be removed
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extra_state ~ extra_gain * Q.output.u,
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]
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# inner has its own unknowns, ps, defaults, and a non-connection equation
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inner = System(
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inner_eqs, t, [extra_state], [extra_gain];
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name = :inner, systems = [P, Q, R, S]
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)
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@named root = System(Equation[], t, systems = [inner])
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isolated, input_vars, output_vars = isolate_subsystem(
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root, root.inner.ap_in, root.inner.ap_out
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)
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inner_isolated = only(get_systems(isolated))
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@test Set(nameof.(get_systems(inner_isolated))) == Set([:Q, :R])
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# The Q→R connection AP is kept; extra_state equation and boundary APs are removed
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@test length(get_eqs(inner_isolated)) == 1
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# extra_state, extra_gain, their defaults, and the algebraic equation are stripped
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@test isempty(get_unknowns(inner_isolated))
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@test isempty(get_ps(inner_isolated))
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@test isempty(get_observed(inner_isolated))
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@test isempty(get_defaults(inner_isolated))
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# root is also clean
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@test isempty(get_unknowns(isolated))
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@test isempty(get_ps(isolated))
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end
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end
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end
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using DynamicQuantities

‎src/ModelingToolkit.jl‎

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@@ -163,6 +163,7 @@ export TearingState
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export Clock, SolverStepClock, TimeDomain
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export get_sensitivity_function, get_comp_sensitivity_function,
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get_looptransfer_function, get_sensitivity, get_comp_sensitivity, get_looptransfer
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export isolate_subsystem
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function FMIComponent end
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