keyword argument x_guesses is not passed to pypesto problem

Hey,

I wanted to use the keyword argument x_guesses to set some customised parameter start points for the optimization, using

obj = importer.create_objective(model=amici_model)
problem = importer.create_problem(obj, x_guesses=x_guesses)

This failed because x_guesses as keyword argument is only passed to the objective and not to the problem.

I could fix it by adding x_guesses = None before **kwargs in line 311 of pyPESTO/petab/importer.py (https://github.com/ICB-DCM/pyPESTO/blob/master/pypesto/petab/importer.py#L311) and adding x_guesses=x_guesses in line 349.

I think it would be good to fix it in the develop version as well, so that customised start points for parameter estimation can easily be set. Thank you in advance.

[stobiblum]

Per default pyPESTO creates x_guesses automatically for all starts before starting with the following optimization steps. But pyPESTO also offers the possibility to apply customised x_guesses, which are passed to the objective and not the problem. Because they are currently not passed to the problem itself, the customised x_guesses wont be recognized as start points for the optimization.

[yannikschaelte]

Agreed! In general, we should allow all arguments in problem/objective constructors in the petab factory methods as well, if they make sense.