Contributing to this project
Please take a moment to review this document in order to make the contribution process easy and effective for everyone involved.
Following these guidelines helps to communicate that you respect the time of the developers managing and developing this open source project. In return, they should reciprocate that respect in addressing your issue or assessing patches and features.
Using the issue tracker
Please do not use the issue tracker for personal support requests (use our igraph support forum).
Please do not derail or troll issues. Keep the discussion on topic and respect the opinions of others.
Please also take a look at our tips on writing igraph code before getting your hands dirty.
A bug is a demonstrable problem that is caused by the code in the repository. Good bug reports are extremely helpful - thank you!
Guidelines for bug reports:
Make sure that the bug is in the C code of igraph and not in one of the higher level interfaces — if you are using igraph from R, Python or Mathematica, consider submitting your issue in igraph/rigraph, igraph/python-igraph or szhorvat/IGraphM instead. If you are unsure whether your issue is in the C layer, submit a bug report in the repository of the higher level interface — we will transfer the issue here if it indeed affects the C layer.
Use the GitHub issue search — check if the issue has already been reported.
Check if the issue has been fixed — try to reproduce it using the latest
masteror development branch in the repository.
Isolate the problem — create a short, self-contained, correct example.
A good bug report shouldn't leave others needing to chase you up for more information. Please try to be as detailed as possible in your report. What is your environment? What steps will reproduce the issue? What would you expect to be the outcome? All these details will help people to fix any potential bugs.
Short and descriptive example bug report title
A summary of the issue and the compiler/OS environment in which it occurs. If suitable, include the steps required to reproduce the bug.
- This is the first step
- This is the second step
- Further steps, etc.
<url>- a link to the reduced test case
Any other information you want to share that is relevant to the issue being reported. This might include the lines of code that you have identified as causing the bug, and potential solutions (and your opinions on their merits).
Feature requests are welcome. But take a moment to find out whether your idea fits with the scope and aims of the project. It's up to you to make a strong case to convince the project's developers of the merits of this feature. Please provide as much detail and context as possible.
Good pull requests - patches, improvements, new features - are a fantastic help. They should remain focused in scope and avoid containing unrelated commits.
Please ask first before embarking on any significant pull request (e.g. implementing features, refactoring code, porting to a different language), otherwise you risk spending a lot of time working on something that the project's developers might not want to merge into the project.
Please adhere to the coding conventions used throughout a project (indentation, accurate comments, etc.) and any other requirements (such as test coverage).
Follow this process if you'd like your work considered for inclusion in the project:
Fork the project, clone your fork, and configure the remotes:
# Clone your fork of the repo into the current directory git clone https://github.com/<your-username>/<repo-name> # Navigate to the newly cloned directory cd <repo-name> # Assign the original repo to a remote called "upstream" git remote add upstream https://github.com/<upstream-owner>/<repo-name>
Please checkout the section on branching to see whether you need to branch off from the
masterbranch or the
If you cloned a while ago, get the latest changes from upstream:
git checkout <dev-branch> git pull --rebase upstream <dev-branch>
Create a new topic branch (off the targeted branch, see branching section) to contain your feature, change, or fix:
git checkout -b <topic-branch-name>
Commit your changes in logical chunks. Please adhere to these git commit message guidelines or your code is unlikely be merged into the main project. Use Git's interactive rebase feature to tidy up your commits before making them public.
We have a handy checklist for new igraph functions. If you have added any new functions to igraph, please go through the checklist to ensure that your functions play nicely with the rest of the library.
Locally merge (or rebase) the upstream development branch into your topic branch:
git pull [--rebase] upstream <dev-branch>
Push your topic branch up to your fork:
git push origin <topic-branch-name>
Open a pull request with a clear title and description.
IMPORTANT: By submitting a pull request, you agree to allow the project owner to license your work under the same license as that used by the project.
igraph is committed to semantic versioning. We are currently still in the development release (0.x), which in principle is a mark that the public API is not yet stable. Regardless, we try to maintain semantic versioning also for the development releases. We do so as follows. Any released minor version (0.x.z) will be API backwards-compatible with any previous release of the same minor version (0.x.y, with y < z). This means that if there is an API incompatible change, we will increase the minor version. For example, release 0.8.1 is API backwards-compatible with release 0.8.0. A new release 0.9.0 will be API incompatible with version 0.8.1. Note that this only concerns the public API, internal functions may change also within a minor version.
There will always be two versions of
igraph: the most recent released version, and the next upcoming minor release, which is by definition not yet released. The most recent release version is in the
master branch, while the next upcoming minor release is in the
develop branch. If you make a change that is API incompatible with the most recent release, it must be merged to the
develop branch. If the change is API backwards-compatible, it can be merged to the
master branch. It is possible that you build on recent improvements in the
develop branch, in which case your change should of course target the
develop branch. If you only add new functionality, but do not change anything of the existing API, this should be backwards-compatible, and can be merged in the
When you make a new pull request, please specify the correct target branch. The maintainers of
igraph may decide to retarget your pull request to the correct branch. Retargeting you pull request may result in merge conflicts, so it is always good to decide before starting to work on something whether you should start from the
master branch or from the
develop branch. In most cases, changes in the
master branch will also be merged to the
develop branch by the maintainers.
Writing igraph Code
In general, if you are not sure about something, please ask! You can open an issue on GitHub, open a thread in our igraph support forum, or write to @ntamas, @vtraag, @szhorvat or @gaborcsardi. We prefer the igraph support forum, because then others can learn from it too.
This is a pain to deal with, but we can't avoid it, unfortunately.
So, igraph is licensed under the "General Public License (GPL) version 2, or later". The igraph manual is licensed under the "GNU Free Documentation License". By submitting a patch or pull request, you agree to allow the project owner to license your work under the same license as that used by the project.