Welcome to GRTeclyn's documentation!

GRTeclyn is a flexible numerical relativity code that is the successor to GRChombo, built on the AMReX library. The GRTeclyn source code is available on GitHub under the BSD-3-Clause license.

If you can't find the answers to your questions here, please post your questions on the Discussions section of the GitHub repo.

Where should I start?

Here are some suggestions depending on your goal:

I want to know if GRTeclyn is the right code for my research project

Start with the Capabilities page for an overview of GRTeclyn's current features.

GRTeclyn is not a black-box code. You’ll need to understand how it works, and may need to write your own tools for specific applications. If you're a supervisor planning to assign a student to work on the code, please ensure you have sufficient background in numerical relativity and C++/GPU computing to support them.

For simpler projects e.g. for masters students, consider using the 1D code engrenage, which is a python based code that runs easily on laptops.

I want to compile and run an example (e.g. binary black hole merger)

Check you have the Prerequisites and then follow the instructions for Building and running on CPUs or GPUs. Our guides assume basic command-line experience (that of most new PhD students). We also assume access to a high-performance computing (HPC) cluster - while we provide laptop tips, most realistic simulations require HPC.

Note that the code runs a lot faster on GPUs than on CPUs (up to a factor of 20), so if you can get access to a system with GPU nodes, this will be more efficient for most problems.

I already have NR experience and want to use or adapt the code

  1. Still begin with the Prerequisites and the Building and Running on CPUs or GPUs sections to ensure your environment is set up properly.

  2. Then head to the section on Code Structure, which covers the design philosophy and guidance for adding your own physics.

For ex-GRChombo users, most of the code should look pretty familiar, but there is a helpful guide on Moving from GRChombo that you should start with.

If you have questions, feel free to Contact us — we’ll try to help. But do keep in mind our unofficial motto:

“If you want it, you build it.”

Before publishing results, don’t forget to check the License and citation page.

I found a bug

Please file an issue on GitHub:

  • Include your code version/commit hash
  • Try to include as much information as you can, including:
  • Detailed steps to reproduce the issue
  • Your build/runtime environment
  • Any error messages
  • The expected outcome/output of your run

GitHub Issues are preferred for code-related problems, but you can also post general questions on the Discussions section of the GitHub repo.

I want to contribute to GRTeclyn

That's great! For now GRTeclyn is in development so it is not a good time for others to contribute, but we will post more details here once we are ready for your help.

Disclaimer

GRTeclyn is a research code under active development.
We aim to provide a stable core, but not all features are guaranteed to work perfectly.
Use it at your own risk!