Code for Publication - Level 2 (Level 1+)

Written instructions for rerunning the code to replicate the analysis (ideally in a file called README). E.g., 1) install packages A, B, & C; 2) download data D; 2) Run script E; 3) manually change F; 4) Run script G, etc.

Ideally go through this process yourself on a computer other than the one you did the analysis on to make sure it works. Even better have a friend do this to make sure someone other than you can follow the steps.

Code for Publication - Level 3 (Level 1/2+)

Automate all the steps for rerunning the analysis using a script. This could be a bash script of a script in the language your code is written in. This should include package installation (ideally w/fixed version numbers if the language allows it). Test this yourself on a computer other than the one you did the analysis, have a friend test it, try to test it on multiple operating systems. Make sure the outputs match the paper.

Code for Publication - Level 4+ (Level 3+)

There are lots of extra things you can do to make all of this even better:

* Use a workflow system instead of script for automation
* Provide a container (e.g., Docker) with code and data
* Have your code produce either a documented version of itself or the entire paper using literature programming tools (e.g., notebooks , Rmarkdown) (I see @tpoisot already getting ahead of me here in the replies; listen to Tim, he's awesome)