1. GIT AND GITHUB WORKSHOP
Lab Meeting
March 16, 2017
I’m presenting a brief workshop on git, github and R integration
Learned a lot of these techniques from Jenny Bryan
Found it super useful, especially working from multiple stations and has a lot of promise for collaboration
Has anyone used git? Heard of git/github? What do they know?
David Tavernini

2. Outline Introduction Rationale: Smooth workflow Prevents headaches
Becoming more prevalent
Computers shouldn’t be intimidating
Outline:
Introduction to VC
Local git*
git in R*
Using git remotely*
Perks of GitHub*
Simply put, git is a version control system. Allows you to track changes, make edits, and revert to previous states.
When I learned it, I found it very beneficial and gives me more confidence in my edits
Very smooth workflow
Prevents headaches
Becoming more prevalent in collaborative environments
Command line can be scary, but I hope I can make it a bit easier
I’ll first give a brief outline of version control and what git actually is
Provide a brief tutorial on using git locally (within one computer)
Integrating git with Rstudio
DISCLAIMER: Not an expert and there are many features available that I don’t know how to utilize. I’d recommend looking deeper if you are trying to do anything you perceive as complex.

3. Uncertainty in edits you make
Introduction
Problem:
Numerous file edits
Uncertainty in edits you make
Need to log changes (collaborative environment)
Solution:
Maintain accessibility of certain editing milestones
Track changes, when they were made, and who by
What is the point of version control:
Typically you anticipate making numerous edits to your files
You are unsure if your edits will be better in the long run
You need to track changes, especially prevalent in a collaborative environment when you want to see others changes

4. Version Control Version Control
For this, we use version control, which allows you to revert to previous changes. Has anyone experienced this method? What if I told you there’s a better way?

5. What is git? git locally Version control system
Keeps a log of noted changes in repository
Repository “repo”: Directory where git operates
Saves snapshots of repo when user makes a “commit”
Branching
Analogy: filing cabinet
So git is a version control sytem. It operates in a repository, which is simply a file directory initialized by git. Essentially you assign a directory to be a repository and git keeps a log of any changes which occurs in that directory. Once initialized, as you make changes to the files within, you commit changes, which is essentially telling git to take a snapshot of the directory and keep it in a log.
Conceptual model
After initializing a directory, you make changes to files in your working directory. When ready you “stage” them for changes and commit them to take a snapshot of the current space
It also allows for branching which allows you to divert off the current series of snapshots to make changes without affecting the orginal stream of work.

6. git locally
TIME
Heres a diagram of a typical git workflow.

7. git demonstration git locally Context:
Have an empty directory for your project workspace
Setup directory for git
Add files, make changes, commit
Branch off and make changes
So let’s try it out. We’ll start with the fundamentals. In this example we will try and get a directory initialized for a project, add some files make some changes

8. git demonstration git locally Context:
Have an empty directory for your project workspace
Setup directory for git
Add files and make changes
Branch off to make changes
So let’s try it out. We’ll start with the fundamentals. In this example we will try and get a directory initialized for a project, add some files make some changes
Obligatory disclaimer: working in console CAN cause damage if you don’t know what you are doing.

9. git with R git in R Project directories
Allows a directory to be specified as project
Sets working directory to be within project
Integrating with git
R provides basic graphical user interface (GUI)
Many limitations, good for basic use
What’s nice is that git allows us to integrate its functionality within an R environment. Who uses Rstudio? Anyone work with project files

10. git + R Demonstration git in R Context:
You need to setup a directory for R work
Initialize R project with Git
Create scripts
Make commits
Branching

11. What is GitHub? GitHub Free online service to act as a remote repo
Users make changes, commit to local repo, and push to GitHub
When multiple machines are used, you can push and pull
Analogy: common filing cabinet

12. Advantages GitHub Works well in collaborative environment:
Tracks changes from multiple authors
Good documentation of changes
Works especially well with text/Markdown documents
Optionally allows open access
Others can clone your repo and make improvements
E.g. create a model script for others to use/develop
Github is very good for a collaborative environment:
Check history of commits, and who made them
Discussions
Issues
Explore hadleys repo

13. Integrating git, Github and RStudio
Context:
Creating a project shared among others
Open a repo in GitHub
Begin project in R
Clone to local computer
Make changes and commit
Obligatory disclaimer: refrain from putting any (current or future) sensitive information on github.

14. Optional: Fork/Pull request
Fork off other repos within github
Make changes and make pull request
Experimental exercise

15. Questions?