Idefix code documentation

About Idefix

Idefix is designed to be a performance-portable astrophysical code. This means that it can run both on your laptop’s cpu or on the largest GPU HPCs recently bought by your university. More technically, Idefix can run in serial, use OpenMP and/or MPI (message passing interface) for parallelization, and use CUDA or Xeon-Phi for out of chip acceleration. Of course, all these capabilities are embedded within one single code, so the code relies on relatively abstracted classes and objects available in C++17, which are not necessarily familiar to astrophysicists. A large effort has been devoted to simplify this level of abstraction so that the code can be modified by researchers and students familiar with C and who are aware of basic object-oriented concepts.

In order to ease the transition from more common codes, Idefix has been designed to be close to the PLUTO code. Several of the data structures have identical names, input files are very similar and the numerical integration algorithm is essentially the same (but with some major modification to its structure). Hence, your favourite PLUTO setup can be converted into an Idefix setup within a couple of hours.

Requirements

Idefix is written is standard C++17 and does not rely on any external library in serial (non MPI). Idefix requires a C++17 compatible compiler. It has been tested successfully with GCC (>8), Intel compiler suite (>2018) and Clang on both Intel and AMD CPUs. Idefix has also been tested on NVIDIA GPUs (Pascal, Volta and Ampere architectures) using the nvcc (>10) compiler, and on AMD GPUs (Radeon Mi50) using the hipcc compiler. Idefix relies internally on the Kokkos library, which is bundled with Idefix as a git submodule and compiled on the fly, hence no external installation is required. When using MPI parallelisation, Idefix relies on an external MPI library. Idefix has been tested successfully with OpenMPI and IntelMPI libraries. When used on GPU architectures, Idefix assumes that the MPI library is GPU-Aware. If unsure, check this last point with your system administrator.

Terms and condition of Use

Idefix is distributed freely under the CeCILL license, a free software license adapted to both international and French legal matters, in the spirit of and retaining compatibility with the GNU General Public License (GPL). We expect Idefix to be referenced and acknowledeged by authors in their publications.

Idefix data structure and algorithm are derived from Andrea Mignone’s PLUTO code, released under the GPL license. Idefix also relies on the Kokkos performance portability programming ecosystem released under the terms of Contract DE-NA0003525 with National Technology & Engineering Solutions of Sandia, LLC (NTESS).

Main Contributors

Geoffroy Lesur: code design and architecture
Soufiane Baghdadi: code optimisation, 2D Riemann solvers, RKL scheme
Gaylor Wafflard-Fernandez: planet-disc interaction
Clément Robert: gitlab integration, linter
Jean Kempf & François Rincon: anisotropic diffusion

About this documentation

This documentation has automatically been generated on Jan 26, 2023 from the following Idefix commit:

Commit: 08d7c24bd4

Acknowledgements

The developement of Idefix is supported by the European Research Council (ERC) under the European Union Horizon 2020 research and innovation programme (Grant agreement No. 815559 (MHDiscs))

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