fix: fix linearization tests

Author: vyudu

src/inputoutput.jl

@@ -163,7 +163,7 @@ has_var(ex, x) = x ∈ Set(get_variables(ex))
     (f_oop, f_ip), x_sym, p_sym, io_sys = generate_control_function(
             sys::AbstractODESystem,
             inputs             = unbound_inputs(sys),
-            disturbance_inputs = nothing;
+            disturbance_inputs = Any[];
             implicit_dae       = false,
             simplify           = false,
         )
@@ -287,7 +287,7 @@ function inputs_to_parameters!(state::TransformationState, inputsyms)
             push!(new_fullvars, v)
         end
     end
-    ninputs == 0 && return (state, 1:0)
+    ninputs == 0 && return state
 
     nvars = ndsts(graph) - ninputs
     new_graph = BipartiteGraph(nsrcs(graph), nvars, Val(false))
@@ -316,14 +316,13 @@ function inputs_to_parameters!(state::TransformationState, inputsyms)
     @set! sys.unknowns = setdiff(unknowns(sys), keys(input_to_parameters))
     ps = parameters(sys)
 
-    if io !== nothing
-        inputs, = io
+    if inputsyms !== nothing
         # Change order of new parameters to correspond to user-provided order in argument `inputs`
         d = Dict{Any, Int}()
         for (i, inp) in enumerate(new_parameters)
             d[inp] = i
         end
-        permutation = [d[i] for i in inputs]
+        permutation = [d[i] for i in inputsyms]
         new_parameters = new_parameters[permutation]
     end
 
@@ -332,8 +331,7 @@ function inputs_to_parameters!(state::TransformationState, inputsyms)
     @set! state.sys = sys
     @set! state.fullvars = new_fullvars
     @set! state.structure = structure
-    base_params = length(ps)
-    return state, (base_params + 1):(base_params + length(new_parameters)) # (1:length(new_parameters)) .+ base_params
+    return state
 end
 
 """
@@ -359,7 +357,7 @@ function get_disturbance_system(dist::DisturbanceModel{<:ODESystem})
 end
 
 """
-    (f_oop, f_ip), augmented_sys, dvs, p = add_input_disturbance(sys, dist::DisturbanceModel, inputs = nothing)
+    (f_oop, f_ip), augmented_sys, dvs, p = add_input_disturbance(sys, dist::DisturbanceModel, inputs = Any[])
 
 Add a model of an unmeasured disturbance to `sys`. The disturbance model is an instance of [`DisturbanceModel`](@ref).
 
@@ -408,7 +406,7 @@ model_outputs = [model.inertia1.w, model.inertia2.w, model.inertia1.phi, model.i
 
 `f_oop` will have an extra state corresponding to the integrator in the disturbance model. This state will not be affected by any input, but will affect the dynamics from where it enters, in this case it will affect additively from `model.torque.tau.u`.
 """
-function add_input_disturbance(sys, dist::DisturbanceModel, inputs = nothing; kwargs...)
+function add_input_disturbance(sys, dist::DisturbanceModel, inputs = Any[]; kwargs...)
     t = get_iv(sys)
     @variables d(t)=0 [disturbance = true]
     @variables u(t)=0 [input = true] # New system input

src/linearization.jl

@@ -126,7 +126,7 @@ function linearization_function(sys::AbstractSystem, inputs,
     end
 
     lin_fun = LinearizationFunction(
-        diff_idxs, alge_idxs, length(unknowns(sys)),
+        diff_idxs, alge_idxs, inputs, length(unknowns(sys)),
         prob, h, u0 === nothing ? nothing : similar(u0), uf_jac, h_jac, pf_jac,
         hp_jac, initializealg, initialization_kwargs)
     return lin_fun, sys

src/systems/diffeqs/odesystem.jl

@@ -470,7 +470,7 @@ Generates a function that computes the observed value(s) `ts` in the system `sys
 - `eval_expression = false`: If true and `expression = false`, evaluates the returned function in the module `eval_module`
 - `output_type = Array` the type of the array generated by a out-of-place vector-valued function
 - `param_only = false` if true, only allow the generated function to access system parameters
-- `inputs = nothing` additinoal symbolic variables that should be provided to the generated function
+- `inputs = Any[]` additional symbolic variables that should be provided to the generated function
 - `checkbounds = true` checks bounds if true when destructuring parameters
 - `op = Operator` sets the recursion terminator for the walk done by `vars` to identify the variables that appear in `ts`. See the documentation for `vars` for more detail.
 - `throw = true` if true, throw an error when generating a function for `ts` that reference variables that do not exist.
@@ -500,8 +500,8 @@ For example, a function `g(op, unknowns, p..., inputs, t)` will be the in-place
 an array of inputs `inputs` is given, and `param_only` is false for a time-dependent system.
 """
 function build_explicit_observed_function(sys, ts;
-        inputs = nothing,
-        disturbance_inputs = nothing,
+        inputs = Any[],
+        disturbance_inputs = Any[],
         disturbance_argument = false,
         expression = false,
         eval_expression = false,
@@ -574,13 +574,13 @@ function build_explicit_observed_function(sys, ts;
     else
         (unknowns(sys),)
     end
-    if inputs === nothing
+    if isempty(inputs)
         inputs = ()
     else
         ps = setdiff(ps, inputs) # Inputs have been converted to parameters by io_preprocessing, remove those from the parameter list
         inputs = (inputs,)
     end
-    if disturbance_inputs !== nothing
+    if !isempty(disturbance_inputs)
         # Disturbance inputs may or may not be included as inputs, depending on disturbance_argument
         ps = setdiff(ps, disturbance_inputs)
     end

src/systems/systems.jl

@@ -29,8 +29,8 @@ topological sort of the observed equations in `sys`.
 function structural_simplify(
         sys::AbstractSystem; additional_passes = [], simplify = false, split = true,
         allow_symbolic = false, allow_parameter = true, conservative = false, fully_determined = true,
-        inputs = nothing, outputs = nothing,
-        disturbance_inputs = nothing,
+        inputs = Any[], outputs = Any[],
+        disturbance_inputs = Any[],
         kwargs...)
     isscheduled(sys) && throw(RepeatedStructuralSimplificationError())
     newsys′ = __structural_simplify(sys; simplify,

src/systems/systemstructure.jl

@@ -659,8 +659,8 @@ end
 
 function structural_simplify!(state::TearingState; simplify = false,
         check_consistency = true, fully_determined = true, warn_initialize_determined = true,
-        inputs = nothing, outputs = nothing, 
-        disturbance_inputs = nothing,
+        inputs = Any[], outputs = Any[],
+        disturbance_inputs = Any[],
         kwargs...)
     if state.sys isa ODESystem
         ci = ModelingToolkit.ClockInference(state)
@@ -671,7 +671,7 @@ function structural_simplify!(state::TearingState; simplify = false,
         cont_inputs = [inputs; clocked_inputs[continuous_id]]
         sys = _structural_simplify!(tss[continuous_id]; simplify,
             check_consistency, fully_determined,
-            cont_inputs, outputs, disturbance_inputs,
+            inputs = cont_inputs, outputs, disturbance_inputs,
             kwargs...)
         if length(tss) > 1
             if continuous_id > 0
@@ -716,8 +716,8 @@ end
 function _structural_simplify!(state::TearingState; simplify = false,
         check_consistency = true, fully_determined = true, warn_initialize_determined = false,
         dummy_derivative = true,
-        inputs = nothing, outputs = nothing,
-        disturbance_inputs = nothing,
+        inputs = Any[], outputs = Any[],
+        disturbance_inputs = Any[],
         kwargs...)
     if fully_determined isa Bool
         check_consistency &= fully_determined

test/downstream/linearize.jl

@@ -87,10 +87,10 @@ connections = [f.y ~ c.r # filtered reference to controller reference
 
 @named cl = ODESystem(connections, t, systems = [f, c, p])
 
-lsys0, ssys = linearize(cl, [f.u], [p.x])
+lsys0, ssys = linearize(cl)
 desired_order = [f.x, p.x]
 lsys = ModelingToolkit.reorder_unknowns(lsys0, unknowns(ssys), desired_order)
-lsys1, ssys = linearize(cl, [f.u], [p.x]; autodiff = AutoFiniteDiff())
+lsys1, ssys = linearize(cl; autodiff = AutoFiniteDiff())
 lsys2 = ModelingToolkit.reorder_unknowns(lsys1, unknowns(ssys), desired_order)
 
 @test lsys.A == lsys2.A == [-2 0; 1 -2]
@@ -266,7 +266,7 @@ closed_loop = ODESystem(connections, t, systems = [model, pid, filt, sensor, r,
         filt.xd => 0.0
     ])
 
-@test_nowarn linearize(closed_loop, :r, :y; warn_empty_op = false)
+@test_nowarn linearize(closed_loop; warn_empty_op = false)
 
 # https://discourse.julialang.org/t/mtk-change-in-linearize/115760/3
 @mtkmodel Tank_noi begin