Additional state specification

[teubert]

Requirement Text Allow the user to specify additional states (e.g., nonlinear states) in surrogate model generation

Background Information The DMD surrogate model generation algorithm linearizes the model. To counter this sometimes additional non-linear states are added (e.g., the product of 2 states).

Suggested Solution My first thought is to allow the user to specify an additional_states(x) function which takes the state (x) and returns additional states to be added (e.g., {python 'xy' = x['x'] * x['y'] or python 'x2' = x['x'] ** 2)

DoD

• [ ] Implement feature
• [ ] Add to example
• [ ] Add to tutorial
• [ ] Add tests
• [ ] Add to change notes for next release