fix: fix vector parameter discovery when used both unscalarized and partially scalarized

Author: AayushSabharwal

src/systems/nonlinear/nonlinearsystem.jl

@@ -219,6 +219,12 @@ function NonlinearSystem(eqs; kwargs...)
                 push!(new_ps, p)
             end
         else
+            if symbolic_type(p) == ArraySymbolic() &&
+               Symbolics.shape(unwrap(p)) != Symbolics.Unknown()
+                for i in eachindex(p)
+                    delete!(new_ps, p[i])
+                end
+            end
             push!(new_ps, p)
         end
     end

test/nonlinearsystem.jl

@@ -4,6 +4,7 @@ using DiffEqBase, SparseArrays
 using Test
 using NonlinearSolve
 using ForwardDiff
+using SymbolicIndexingInterface
 using ModelingToolkit: value
 using ModelingToolkit: get_default_or_guess, MTKParameters
 
@@ -380,3 +381,12 @@ end
     @test_throws ["single equation", "unknown"] IntervalNonlinearFunctionExpr(
         sys, (0.0, 1.0))
 end
+
+@testset "Vector parameter used unscalarized and partially scalarized" begin
+    @variables x y
+    @parameters p[1:2] (f::Function)(..)
+
+    @mtkbuild sys = NonlinearSystem([x^2 - p[1]^2 ~ 0, y^2 ~ f(p)])
+    @test !any(isequal(p[1]), parameters(sys))
+    @test is_parameter(sys, p)
+end