Base class for all subcircuits. You'll use me or my many subclasses a lot.

Construct an instance of me with a reference to an Elements object, which you must have in context from a "with ... as" call to a Netlist object. Then call that instance as many times as you like in the same context (important!) to generate a line referencing the subcircuit. The args for the call are the main-circuit nodes to which the subcircuit nodes defined in nodes are attached. Any keywords supplied define values of your params other than the default.

Define the subcircuit name, nodes, and any parameters with the name, nodes and any params attributes, which may be subclass rather than instance attributes. If name is not defined, the class name will be used, but beware that you cannot construct two instance of me with the same name.

Parameter values will be listed on the "X" subcircuit call in the netlist. They override any global parameters with identical names (Ngspice Manual 2.8.4).

You CANNOT access the values of subcircuit parameters in your subclass's setup method, because the user is free to define them differently in each f.X call, which happen after setup is done. Use a brace expression (e.g., "{xxx}") in your setup method to let Ngspice access the value of a parameter (e.g., xxx=1.23 at simulation time.

Usually a better option than relying on params is to define an instance attribute before setup is called, although this parameterizes a subcircuit's behavior for all calls of the instance. You can define the attribute class-wide in the class definition or with a constructor keyword, although you should still provide a class-wide default definition in your code just to make clear that there will be an attribute-type parameter.

To use an Ngspice netlist file as a subcircuit, e.g., a .CIR file provided by an IC vendor, just specify the circuitFile path as an attribute or in my constructor, and don't write your own setup method. (Or, if you set the useDocstring keyword or class/instance attribute True, put the netlist in your subclass's docstring.) I'll take care of putting the netlist into a subcircuit. You still have to specify the subcircuit's name, nodes, and any params as subclass or instance attributes.

For convenience, you can set attributes of an instance of me with constructor keywords (except for circuitFile). Remember, those are different than keywords supplied to a f.X call, which specify non-default values for subcircuit parameters.

NOTE: You can override a subclass's class-wide params attribute by setting a constructor keyword params to a new dict for just that instance, giving it different default parameter values from other instances of the subclass. Not an especially compelling use case, but it's there.