In 1959 C.P. Snow's famous lecture, "The Two Cultures", decried the failure of educated people in the sciences and humanities to work together. Today we have a similar divide opening between those who write software for science and those who write it for "everything else". In this talk, we'll review the current state of affairs and look at what Julia might do to remedy the situation. The hope is that Julia can be a great programming language not just for science, but for programmers everywhere.

1. The Two
Cultures
Joshua Ballanco, Ph.D.
‸ of
Programming

2. Are you:
✔ a Scientist
✔ a Programmer
✔ tired from all the Linear Algebra

3. Background
• 1991 – Learn to program (age 11)
• 1996 – Recompile Linux kernel
• 1998 – Do something with Linux other than recompile a kernel
• 2002 – B.S. in Chemistry
• 2008 – Server Software Engineer at Apple
• 2012 – Ph.D. in Chemical Biology
• 2013 – Software Engineering Consultant
• 2014 – Discover Julia

4. Background
Science Programming

5. What’s this about?
Thesis
“A good scientific programming language
will also be a good general purpose
programming language.”

6. What’s this about?
Question
Do scientists and programmers
program differently?

7. History
1959

8. History
• The Two Cultures
• Science
• Humanities

9. History
• English perspective
• Humanities look down on the sciences…
• But humanities could benefit from scientific
method

10. History
• American perspective
• Scientists reject need for study of humanities…
• But scientists could benefit from improved
communication skills

11. History
• Humanities – Understand humans and our
interaction with the world
• Sciences – Discover the immutable laws that
govern nature
• Both – Seek to increase the wealth of human
knowledge

12. Scientists vs Programmers
• Tooling
• Version Control
• Editors/IDEs
• Debuggers
http://biorxiv.org/content/early/2016/05/13/048744

13. Scientists vs Programmers
• Code Organization
Rails CellProfiler
SLOC: 209114 SLOC: 147512

14. Scientists vs Programmers
• Priorities
“Yet we should not pass up our
opportunities in that critical 3%.”
“We should forget about small efficiencies,
say about 97% of the time: premature
optimization is the root of all evil.”
– Donald Knuth

15. Programmers = Humanities?
https://www.youtube.com/watch?v=9LfmrkyP81M

16. Programmers = Humanities?
https://www.dreamsongs.com/MFASoftware.html

17. The Two Cultures
• Scientists – Programming is a tool to generate
interesting results
• Programmers – Software is an artifact that should
be crafted with care
• Both – Make the computer do stuff!

18. Why do I care?
0
700
1400
2100
2800
3500
NumPy SciPy Rails
1000x Lines of Code Contributors

19. Why do I care?

20. Why do I care?
http://www.economist.com/news/science-and-technology/21695377-professors-
unprofessional-programs-have-created-new-profession-more

21. Why do I care?
Julia can be the language that
unifies science and programming

22. How?
• Pkg.generate()
• Readability
• Array indexing
• Testing
• REPL

23. How?
• Pkg.generate()
• Brilliant!
• Embraces the importance of community
• What about Project.generate()?

24. How?
• Readability
• Unicode operators? Brilliant…sometimes!
• “Any fool can write code that a computer can
understand. Good programmers write code that
humans can understand.” – Martin Fowler

25. How?
• Array indexing
• Arbitrary indexing? Brilliant!
• “1-based indexing…eww!”
• “I don't know how many of you have ever met
Dijkstra, but you probably know that arrogance in
computer science is measured in nano-
Dijkstras.” – Alan Kay

26. How?
• Testing
• Julia: @test, @test_throws
• Ruby:

27. How?
• REPL
• Shell? Help? C++?!? Brilliant!
• REPL as exploration vs REPL as dev tool
• workspace()? Brilliant!
• method redefinition… boo! (Infamous #265)

28. How?
You!

29. Joshua Ballanco
jballanc@gmail.com
https://github.com/jballanc
@manhattanmetric
Thank You!