Generalizing the interface of pyFANS

[IshaanDesai]

Currently, pyFANS wraps the FANS functionality into an interface as required by the Micro Manager. However, pyFANS can also provide a general interface so that FANS functionality can be used via a Python script. To use the current interface in a Python script, pyFANS needs to be compiled as a shared library. The shared library file (for example, PyFANS.cpython-312-x86_64-linux-gnu.so) needs to be in the same folder as the Python script that uses PyFANS. The current interface can be used in the following way:

import importlib

micro_problem = getattr(importlib.import_module("PyFANS", "MicroSimulation"),"MicroSimulation")

input_data = dict()
input_data["strains1to3"] = [1, 2, 3] # dummy strain values
intput_data["strains4to6"] = [4, 5, 6]  # dummy strain values

micro_output = micro_problem.solve(input_data)

stresses1to3 = micro_output["stresses1to3"]
stresses4to6 = micro_output["stresses4to6"]

stresses = stresses1to3 + stresses4to6

cmat1 = micro_output["cmat1"]
cmat2 = micro_output["cmat2"]
cmat3 = micro_output["cmat3"]
cmat4 = micro_output["cmat4"]
cmat5 = micro_output["cmat5"]
cmat6 = micro_output["cmat6"]
cmat7 = micro_output["cmat7"]

cmat = cmat1 + cmat2 + cmat3 + cmat4 + cmat5 + cmat6 + cmat7

This interface is restrictive in the way it breaks down the stress and stiffness tensors. This is done because preCICE currently cannot handle tensorial data. But a general interface of pyFANS could look like:

import importlib

micro_problem = getattr(importlib.import_module("PyFANS", "MicroSimulation"),"MicroSimulation")

strains = [1, 2, 3, 4, 5, 6]  # dummy values

micro_output = micro_problem.get_solution(strains)

stresses = micro_output[0]
cmat = micro_output[1]

Eventually, we can also make pyFANS a Python package, such that one can directly do import pyFANS. The shared library style of importing is a requirement of the Micro Manager.

Open questions about the general interface are:

1. Should there be one function called get_solution or solve which accepts strains and returns the stress and stiffness values?
2. Should there be separate functions get_stresses and get_stiffness?
3. What should be the Python side input data format for strains and the output data format for stress and stiffness? Is Python list sufficient?