Merge pull request SciML#3822 from SciML/as/fix-pdeps

fix: fix parameter dependencies dependent on scalarized array parameter

Author: AayushSabharwal

src/systems/abstractsystem.jl

@@ -2757,7 +2757,9 @@ function process_parameter_equations(sys::AbstractSystem)
             is_parameter(sys, sym) ||
                 symbolic_type(sym) == ArraySymbolic() &&
                 is_sized_array_symbolic(sym) &&
-                all(Base.Fix1(is_parameter, sys), collect(sym))
+                all(Base.Fix1(is_parameter, sys), collect(sym)) ||
+                iscall(sym) &&
+                operation(sym) === getindex && is_parameter(sys, arguments(sym)[1])
         end
             # Everything in `varsbuf` is a parameter, so this is a cheap `is_parameter`
             # check.

test/parameter_dependencies.jl

@@ -389,3 +389,12 @@ end
         [x(k - 1) ~ x(k) + y(k) + p2, p2 ~ 2p1], t)
     @test is_parameter(sys, p1)
 end
+
+@testset "Scalarized array as RHS of parameter dependency" begin
+    @parameters p[1:2] p1 p2
+    @variables x(t)
+    @named sys = System([D(x) ~ x, p1 ~ p[1], p2 ~ p[2]], t)
+    @test any(isequal(p), ModelingToolkit.get_ps(sys))
+    sys = mtkcompile(sys)
+    @test length(ModelingToolkit.parameter_dependencies(sys)) == 2
+end