Why scientists should use version control¶
Imagine writing a simulation, getting results you are happy with, then making changes to improve the code — only to discover that the new version no longer reproduces your original results, and you cannot remember exactly what you changed. This is an extremely common and genuinely frustrating experience when writing new software.
Version control is the solution. Git is a tool that records every change you make to your project files, along with a short description of what changed and why. At any point you can look back through the complete history of your work, compare any two versions side by side, or restore an earlier state exactly.
GitHub is a website that stores a copy of your Git history in the cloud, making it accessible from any computer and easy to share with collaborators. It is the most widely used code-hosting platform in the scientific community.
Key Concept: The Core Git Workflow
The everyday Git workflow involves three steps that you will repeat throughout this tutorial and beyond:
- Stage the changes you want to save:
git add - Commit with a short message describing what changed:
git commit - Push your commit to GitHub:
git push
Think of a commit as a labelled snapshot of your project at a specific moment.
A good commit message is short but informative. add sphere form factor function
is far more useful than update or changes when you are reading history six
months later.
Installing Git¶
Git is often pre-installed. Check by running git --version in a terminal.
If it is absent, install the Xcode Command Line Tools:
Alternatively, download Git from git-scm.com/downloads.
Download the installer from https://git-scm.com/install/windows and accept the default options. The installer includes Git Bash, a terminal that works well for the commands in this tutorial.
Confirm the installation:
Configuring Git¶
Before using Git for the first time, tell it your name and email address. These are attached to every commit and appear in your project history:
$ git config --global user.name "Your Name"
$ git config --global user.email "your.email@example.com"
Use the same email address you will register with GitHub.
Creating a GitHub account¶
Go to github.com and create a free account if you do not already have one.
What's next: SSH Keys — connecting your computer to GitHub securely so that you can push code without entering a password every time.