PEM survival model: unstructured hazard
[PEM survival model: gamma hazard](examples/Test pem_survival_model_gamma with simulated data.ipynb)
[PEM survival model: randomwalk hazard](examples/Test pem_survival_model_randomwalk with simulated data.ipynb)
[PEM survival model: time-dependent effects](examples/Test pem_survival_model_timevarying with simulated data.ipynb)
[User-supplied PEM survival model with gamma hazard](examples/Test new_gamma_survival_model with simulated data.ipynb)