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{"@context":"https://schema.org","@type":"QAPage","mainEntity":{"@type":"Question","name":"Using a class method in a NonlinearIOSystem","text":"
I am trying to use a class method in a NonlinearIOSystem.  To test, I adapted the predator-prey example such that the predprey_rhs function becomes a method in the new predprey class.  Then, I create an instance of the predprey class (pp), and create the NonlinearIOSystem using the pp.predprey_rhs method.  All good to that point.  When I try to calculate the open-loop response with control.input_output_response, I get \"TypeError: dynamics() takes 4 positional arguments but 5 were given\".  The method predprey_rhs has the self argument in its definition, so that shouldn't be a problem.  Anyone have any ideas?
","upvoteCount":1,"answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"
I figured it out.  Apparently, \"params\" is required as an argument for the predprey_rhs method.  Previously, I defined the parameters in init, and didn't include \"params\" as a predprey_rhs method.  Once I added it back in, even though is wasn't used, the error went away.  I still don't understand why it threw the TypeError, but no matter.
","upvoteCount":1,"url":"https://github.com/python-control/python-control/discussions/630#discussioncomment-855269"}}}