A simple implementation of PETSc's ASM preconditioner that is focussed on the case of small matrices. We avoid the overhead of KSP and PC objects for each block and just use the dense inverse.
You need a recent firedrake install
curl -O https://raw.githubusercontent.com/firedrakeproject/firedrake/master/scripts/firedrake-install
python3 firedrake-install
Then there are two variants:
A) Simply run
pip install git+https://github.com/florianwechsung/TinyASM
B) clone the repo including submodules:
git clone --recursive git@github.com:florianwechsung/TinyASM.git
and then
cd TinyASM
pip3 install -e .