Developer documentation

Design details

Models

In Thunderbolt a model essentially describes a set of PDEs, their boundary conditions and their coupling information on a high level.

Functions

Functions are simply semidiscretizations together with boundary condition and coupling information for the semidiscrete form.

Problems

A function equipped with a time interval and an initial guess.

Operators

Operators decouple the function description from their evaluation.

assemble_element

Questions:

1. How to deal with quasi-static problems which also need velocities?
2. How to make recursive assemble_element definitions for volume coupled problems?

Solver

Solvers construct operators from given functions and solve some problem with the function info.

setup_solver_caches(problem, solver, t₀) takes the problem and a solver to setup the operators needed during solve.

Questions:

1. How to control which exact operator?
2. When and how to check if the operator is compatible with the solver?

See also my brain flushing in real time some design decisions.