Add parent to hierarchical systems and set it in structural_simplify

Author: YingboMa

src/systems/abstractsystem.jl

@@ -230,7 +230,8 @@ for prop in [:eqs
     :gui_metadata
     :discrete_subsystems
     :unknown_states
-    :split_idxs]
+    :split_idxs
+    :parent]
     fname1 = Symbol(:get_, prop)
     fname2 = Symbol(:has_, prop)
     @eval begin
@@ -307,6 +308,9 @@ function Base.propertynames(sys::AbstractSystem; private = false)
 end
 
 function Base.getproperty(sys::AbstractSystem, name::Symbol; namespace = !iscomplete(sys))
+    if has_parent(sys) && (parent = get_parent(sys); parent !== nothing)
+        sys = parent
+    end
     wrap(getvar(sys, name; namespace = namespace))
 end
 function getvar(sys::AbstractSystem, name::Symbol; namespace = !iscomplete(sys))
@@ -1185,7 +1189,7 @@ macro mtkbuild(expr)
     name = named_expr.args[1]
     esc(quote
         $named_expr
-        $name = complete(structural_simplify($name))
+        $name = $structural_simplify($name)
     end)
 end
 

src/systems/diffeqs/odesystem.jl

@@ -143,6 +143,10 @@ struct ODESystem <: AbstractODESystem
     split_idxs: a vector of vectors of indices for the split parameters.
     """
     split_idxs::Union{Nothing, Vector{Vector{Int}}}
+    """
+    parent: the hierarchical parent system before simplification.
+    """
+    parent::Any
 
     function ODESystem(tag, deqs, iv, dvs, ps, tspan, var_to_name, ctrls, observed, tgrad,
         jac, ctrl_jac, Wfact, Wfact_t, name, systems, defaults,
@@ -151,7 +155,7 @@ struct ODESystem <: AbstractODESystem
         tearing_state = nothing,
         substitutions = nothing, complete = false,
         discrete_subsystems = nothing, unknown_states = nothing,
-        split_idxs = nothing; checks::Union{Bool, Int} = true)
+        split_idxs = nothing, parent = nothing; checks::Union{Bool, Int} = true)
         if checks == true || (checks & CheckComponents) > 0
             check_variables(dvs, iv)
             check_parameters(ps, iv)
@@ -165,7 +169,7 @@ struct ODESystem <: AbstractODESystem
             ctrl_jac, Wfact, Wfact_t, name, systems, defaults, torn_matching,
             connector_type, preface, cevents, devents, metadata, gui_metadata,
             tearing_state, substitutions, complete, discrete_subsystems,
-            unknown_states, split_idxs)
+            unknown_states, split_idxs, parent)
     end
 end
 

src/systems/diffeqs/sdesystem.jl

@@ -115,13 +115,17 @@ struct SDESystem <: AbstractODESystem
     complete: if a model `sys` is complete, then `sys.x` no longer performs namespacing.
     """
     complete::Bool
+    """
+    parent: the hierarchical parent system before simplification.
+    """
+    parent::Any
 
     function SDESystem(tag, deqs, neqs, iv, dvs, ps, tspan, var_to_name, ctrls, observed,
         tgrad,
         jac,
         ctrl_jac, Wfact, Wfact_t, name, systems, defaults, connector_type,
         cevents, devents, metadata = nothing, gui_metadata = nothing,
-        complete = false;
+        complete = false, parent = nothing;
         checks::Union{Bool, Int} = true)
         if checks == true || (checks & CheckComponents) > 0
             check_variables(dvs, iv)
@@ -135,7 +139,7 @@ struct SDESystem <: AbstractODESystem
         new(tag, deqs, neqs, iv, dvs, ps, tspan, var_to_name, ctrls, observed, tgrad, jac,
             ctrl_jac,
             Wfact, Wfact_t, name, systems, defaults, connector_type, cevents, devents,
-            metadata, gui_metadata, complete)
+            metadata, gui_metadata, complete, parent)
     end
 end
 

src/systems/discrete_system/discrete_system.jl

@@ -86,14 +86,18 @@ struct DiscreteSystem <: AbstractTimeDependentSystem
     complete: if a model `sys` is complete, then `sys.x` no longer performs namespacing.
     """
     complete::Bool
+    """
+    parent: the hierarchical parent system before simplification.
+    """
+    parent::Any
 
     function DiscreteSystem(tag, discreteEqs, iv, dvs, ps, tspan, var_to_name, ctrls,
         observed,
         name,
         systems, defaults, preface, connector_type,
         metadata = nothing, gui_metadata = nothing,
         tearing_state = nothing, substitutions = nothing,
-        complete = false; checks::Union{Bool, Int} = true)
+        complete = false, parent = nothing; checks::Union{Bool, Int} = true)
         if checks == true || (checks & CheckComponents) > 0
             check_variables(dvs, iv)
             check_parameters(ps, iv)
@@ -105,7 +109,7 @@ struct DiscreteSystem <: AbstractTimeDependentSystem
             systems,
             defaults,
             preface, connector_type, metadata, gui_metadata,
-            tearing_state, substitutions, complete)
+            tearing_state, substitutions, complete, parent)
     end
 end
 

src/systems/nonlinear/nonlinearsystem.jl

@@ -75,18 +75,23 @@ struct NonlinearSystem <: AbstractTimeIndependentSystem
     complete: if a model `sys` is complete, then `sys.x` no longer performs namespacing.
     """
     complete::Bool
+    """
+    parent: the hierarchical parent system before simplification.
+    """
+    parent::Any
 
     function NonlinearSystem(tag, eqs, states, ps, var_to_name, observed, jac, name,
         systems,
         defaults, connector_type, metadata = nothing,
         gui_metadata = nothing,
         tearing_state = nothing, substitutions = nothing,
-        complete = false; checks::Union{Bool, Int} = true)
+        complete = false, parent = nothing; checks::Union{Bool, Int} = true)
         if checks == true || (checks & CheckUnits) > 0
             all_dimensionless([states; ps]) || check_units(eqs)
         end
         new(tag, eqs, states, ps, var_to_name, observed, jac, name, systems, defaults,
-            connector_type, metadata, gui_metadata, tearing_state, substitutions, complete)
+            connector_type, metadata, gui_metadata, tearing_state, substitutions, complete,
+            parent)
     end
 end
 

src/systems/optimization/optimizationsystem.jl

@@ -56,18 +56,23 @@ struct OptimizationSystem <: AbstractOptimizationSystem
     complete: if a model `sys` is complete, then `sys.x` no longer performs namespacing.
     """
     complete::Bool
+    """
+    parent: the hierarchical parent system before simplification.
+    """
+    parent::Any
 
     function OptimizationSystem(tag, op, states, ps, var_to_name, observed,
         constraints, name, systems, defaults, metadata = nothing,
-        gui_metadata = nothing, complete = false;
+        gui_metadata = nothing, complete = false, parent = nothing;
         checks::Union{Bool, Int} = true)
         if checks == true || (checks & CheckUnits) > 0
             unwrap(op) isa Symbolic && check_units(op)
             check_units(observed)
             all_dimensionless([states; ps]) || check_units(constraints)
         end
         new(tag, op, states, ps, var_to_name, observed,
-            constraints, name, systems, defaults, metadata, gui_metadata, complete)
+            constraints, name, systems, defaults, metadata, gui_metadata, complete,
+            parent)
     end
 end
 

src/systems/systems.jl

@@ -17,6 +17,12 @@ This will convert all `inputs` to parameters and allow them to be unconnected, i
 simplification will allow models where `n_states = n_equations - n_inputs`.
 """
 function structural_simplify(sys::AbstractSystem, io = nothing; simplify = false,
+    kwargs...)
+    newsys = __structural_simplify(sys, io; simplify, kwargs...)
+    @set! newsys.parent = complete(sys)
+    return complete(newsys)
+end
+function __structural_simplify(sys::AbstractSystem, io = nothing; simplify = false,
     kwargs...)
     sys = expand_connections(sys)
     sys isa DiscreteSystem && return sys