Installation guide

SLOTH is written in C++17/C++20. It can be built under Linux and MacOS using CMake.

Two mandatory prerequisites for building SLOTH

• SLOTH is built on top of the MFEM Finite Element library developed in C++ by LLNL¹.
• SLOTH uses Sympy to handle physical properties.

Please ensure that both MFEM and Sympy are properly installed before building SLOTH.

MFEM

MFEM can be installed in several ways but the use of spack on Linux and Homebrewon MacOS is recommended for sake of simplicity.

Installing SLOTH therefore consists of first installing MFEM and compiling SLOTH. The basic procedure is then provided for the Linux platforms using spack, the Linux platforms from source files and the MacOs platforms, but also for supercomputers where SLOTH is intended to be used.

Sympy

SLOTH provides an advanced interface based on Sympy to manage physical properties. The basic procedure also includes instructions for installing SLOTH with this dependency.

Optional dependencies for building SLOTH

• SLOTH utilizes C++ APIs contained within the library libTorch to load PyTorch models. The basic procedure also includes instructions for installing libTorch.
• While SLOTH primarily uses Sympy to handle physical properties, it also provides an interface based on ExprTk (see instructions for installing SLOTH with ExprTk).

---

1. Robert Anderson, Julian Andrej, Andrew Barker, Jamie Bramwell, Jean-Sylvain Camier, Jakub Cerveny, Veselin Dobrev, Yohann Dudouit, Aaron Fisher, Tzanio Kolev, and others. Mfem: a modular finite element methods library. Computers & Mathematics with Applications, 81:42–74, 2021. ↩