Testing and Comparing Backends

If we create a network with a set of rates, we should get the same “ydots” (\(dY_k/dt\)) values regardless of the backend (to roundoff, and maybe interpolation, error)

To facilitate comparing the backends, we have a NetworkCompare helper class that takes a library and evaluates the ydots for different backends. Currently it can work with:

• RateCollection / inline python networks: this uses the built-in eval methods to evaluate each of the rates.

• PythonNetwork modules: this means writing out the network as a .py file, importing it, and then using the functions in the module to evaluate the rates.

• SimpleCxxNetwork : we build a simple test driver and parse the output to get the ydot values.

It will store the ydots in a dict keyed by Nucleus. This is used in the following unit tests in pynucastro/networks/tests/:

• test_compare_cxx_and_python.py : this compares just strong reaction rates

• test_compare_temperature_tabular.py : this compares the evaluation of a TemperatureTabularRate between the inline and module python nets.

As more features are ported to SimpleCxxNetwork, we should extend the testing to compare with python rates.