The StackField class is a collection of separate fields that are organized as a one-dimensional array, either horizontal or vertical. Stack fields maintain the alignment of their component fields.

You cannot map a StackField to an array variable. If you associate the stack field with a reference variable, the component fields in the stack must map to the attributes of that reference variable's class. If the stack field is named, but not associated with a named class definition, OpenROAD creates an unnamed class for the stack field that you can use only in the frame that contains the StackField. You must use dot notation to access the component fields in a named stack field.