Node Output & Design Script Output Inconsistent

[Kulkul]

Hi @Nick_Boyts

Have you tried using DS inside function? Below is an example:

DesignScript Flatten not working in Function

Hi @Mepdot You where missing tab and you need to define your inputs as var: [image] Here is the edited function: def CategoryFamily(in1: var[]..[],in2: var[]..[]) { element1 = Revit.Elements.Element.ElementType(in1); familyinstance1 = Revit.FamilyInstance.ByFamilyType(element1); family1 = Revit.FamilyInstance.GetFamily(familyinstance1); t3 = DSCore.List.Flatten(family1, -1); t4 = DSCore.List.UniqueItems(t3); t5 = DSCore.List.Count(t4); t6 = DSCore.List.AddItemToFront(in2,t4); t7 = …