feat: optionally filter Initial parameters in parameters

Author: AayushSabharwal

src/systems/abstractsystem.jl

@@ -1273,7 +1273,7 @@ Get the parameters of the system `sys` and its subsystems.
 
 See also [`@parameters`](@ref) and [`ModelingToolkit.get_ps`](@ref).
 """
-function parameters(sys::AbstractSystem)
+function parameters(sys::AbstractSystem; initial_parameters = false)
     ps = get_ps(sys)
     if ps == SciMLBase.NullParameters()
         return []
@@ -1282,7 +1282,12 @@ function parameters(sys::AbstractSystem)
         ps = first.(ps)
     end
     systems = get_systems(sys)
-    unique(isempty(systems) ? ps : [ps; reduce(vcat, namespace_parameters.(systems))])
+    result = unique(isempty(systems) ? ps :
+                    [ps; reduce(vcat, namespace_parameters.(systems))])
+    if !initial_parameters
+        filter!(x -> !iscall(x) || !isa(operation(x), Initial), result)
+    end
+    return result
 end
 
 function dependent_parameters(sys::AbstractSystem)
@@ -1310,7 +1315,7 @@ function parameter_dependencies(sys::AbstractSystem)
 end
 
 function full_parameters(sys::AbstractSystem)
-    vcat(parameters(sys), dependent_parameters(sys))
+    vcat(parameters(sys; initial_parameters = true), dependent_parameters(sys))
 end
 
 """