Non ideal optics to emulate manufacturing errors?

[NuggetOfficial]

Dear team,

Im running into a bit of a low end error when trying to do some slightly hacky stuff with the VectorVortexCoronagraph.

For my M.Sc. thesis I am simulating optics such as the VectorVortexCoronagraph and the effect of manufacturing errors on the performance of these optics. In essence, Im implementing the footprint of (in my case) a direct writing system in the vortex patterns that I simulate.

This footprint is a mapping function that says: if I try to write this fast axis orientation (fao), the actual fao that I get will be that instead. When you use something along the lines of a closure in python, this means that I make a function f: x |-> x' where x'-x is the systematic fao offset given x.

Or in pythonic expression

def manufacturing_mapping_closure(x:Field, *arguments_needed_to_close_function) -> Field:
    y: Field = do_something(x)
    return y

# create completely closed f: x |-> x'
manufacturing_mapping_function = partial(manufacturing_mapping_factory, *arguments_needed_to_close_function)

I then take the VectorVortexCoronagraph code and in the __init__ I add a parameter called something like manufacturing_map
and in the make_instance method I wrap the fast_axis_orientation parameter this map:

class NonIdealVectorVortexCoronagraph(hp.AgnosticOpticalElement):
    (...)

    def __init__(self, charge, manufacturing_mapping_function:Callable, lyot_stop=None, ...):
        (...)
        self.manufacturing_map= manufacturing_mapping_function
        (...)

    def make_instance(self, instance_data, input_grid, output_grid, wavelength):
        (...) # clever resampling stuff
        fast_axis_orientation = self.manufacturing_map(fast_axis_orientation) <-- the important part
        (...) 

The current issue is that the manufacturing mapping function as defined in self can't be called. The AgnosticOpticalElement gets the instance data (line 607, in get_instance_data) and then tries to hash the arguments of the function (line 323, in _get_cache_keys). The issue is that fields are an unhashable type.

The function in self also gets a different call signature according to my vscode linter. It shows that the call signature goes from
(Field) -> Field to (input_grid, output_grid, wavelegnth) -> Any.

If I use a global overwrite it works fine but thats quite ugly and really hacky and I don't like it.
Is there a neat way to do this?

Cheers,
Tom