2018 Women in Analytics Conference https://www.womeninanalytics.org/ Data analysts create millions of lines of elegant, powerful code every year. However, because software development is not seen as their primary role, best practices of software engineering often fall to the wayside. Many data analysts are self-taught programmers who haven’t been exposed to tools like version control software, unit testing suites, and System Development Life Cycle (SDLC) processes. Popular software engineering concepts such as Don’t Repeat Yourself (DRY), design patterns, and modularization can vastly improve the quality and efficiency of analytics projects. This talk will provide a high-level introduction to these topics, and will focus on providing resources for additional learning.

1. Treat Your Code Like the
Valuable Software It Is
Amanda Cinnamon
Amanda.cinnamon@daytonanalytics.com

2. Poll
▪ Who here has lost days or even weeks of productivity trying
to track down a bug, recovering lost code, or trying to
understand your own code
▪ How many of you consider yourselves software developers?

3. Introduction
▪ Target audience: analysts who write code
▪ Objective: Basic introduction to principals, tools, and
resources

4. Overview
▪ Tools
▪ Software Testing Frameworks
▪ Version Control
▪ Concepts
▪ Software Development Life Cycle
▪ Don’t Repeat Yourself (DRY)
▪ Design Patterns
▪ Modularization
▪ Cinnamon Axiom

5. Why Don’t Analyst Use Software
Development Tools?
▪ Lack of training
▪ Imposter syndrome
▪ Requires investment of time and money

6. Solution
▪ Knowledgeable mentors
▪ Awareness of available resources
▪ Continuous learning
▪ Owning up to role of software developer

7. Software Development Tools

8. Coding Problem
Problems caused by tiny programming errors appear at the
worst time during my analysis and I spend time debugging
when I should be doing my “real” job!

9. Solution: Software Testing
▪ Types of testing:
▪ Unit tests
▪ Verification
▪ Validation
▪ Integration tests
▪ User test

10. Unit Test Example

11. V & V Test Example
0 0.2 0.4 0.6 0.8 1
0
0.5
1
1.5
Time Ratio (t/t0
)
DragAreaRatio(c
D
S/c
D
S
0
)
WiSS-Generated Generic Chute Drag Area Growth Profiles
Ringslot, WiSS
Cross, WiSS
Solid Flat, WiSS
Ringslot, Theory
Cross, Theory
Solid Flat, Theory
300 400 500 600 700 800 900 1000 1100
1
2
3
4
5
6
7
C-130J-30 Exit Time
Fuselage Station (in. aft)
ExitTime(s)
WiSS
AFI11-231

12. Data Visualization Validation
Source: xkcd.com

13. Coding Problem
I know I fixed this bug already, but it has suddenly reappeared!
That must have happened when I copied Joe’s version of the
algorithm into my code. Now what was the fix again?

14. Solution: Version Control Software
Source: https://git-scm.com

15. Software Development Concepts

16. Problem
I don’t really know where I’m going with this code. I just start at
line one and hope it does something by the time I get to the
last close bracket.

17. Solution: Software Development
Life Cycle

18. Manifesto for Agile Software Development
▪ Customer satisfaction by early and continuous delivery of valuable software
▪ Welcome changing requirements, even in late development
▪ Working software is delivered frequently (weeks rather than months)
▪ Close, daily cooperation between business people and developers
▪ Projects are built around motivated individuals, who should be trusted
▪ Face-to-face conversation is the best form of communication (co-location)
▪ Working software is the primary measure of progress
▪ Sustainable development, able to maintain a constant pace
▪ Continuous attention to technical excellence and good design
▪ Simplicity—the art of maximizing the amount of work not done—is essential
▪ Best architectures, requirements, and designs emerge from self-organizing teams
▪ Regularly, the team reflects on how to become more effective, and adjusts accordingly

19. Coding Problem:
Can you find the copy/past/modify mistake?
These lines are so similar, it seemed easy to just copy/paste
and modify the variable names, but I can’t figure out why it
doesn’t work!

20. Solution: Don’t Repeat Yourself

21. Coding Problem
Everyone on the team has already solved this problem in a
different way. Mike’s solution crashes all the time, but Joe’s
code is slow. Should I write my own algorithm?

22. Solution: Design Patterns
Example: Singleton

23. Coding Problem
I know I’ve written code to do this for another project. It’s in one
of these main.cpp files somewhere.

24. Solution: Modularization
Main
Physics
Model
Data
Logger
Data
Visualization
RNG

25. Coding Problem:
I did this the brute force way last time because I thought I
would never have to do this again

26. Solution: Cinnamon Axiom
You will never do something once.

27. Summary
▪ Doing things the right way and not taking shortcuts saves
time in the long run.

28. Resources
▪ Software testing
▪ Introduction to Test Driven Development by Kent
Beck
▪ Version Control Software
▪ https://git-scm.com/
▪ Software Development Life Cycle
▪ http://agilemanifesto.org/
▪ Don’t Repeat Yourself
▪ http://deviq.com/don-t-repeat-yourself/
▪ Design Patterns
▪ Design Patterns: Elements of Reusable Object-
Oriented Software by Erich Gamma, Richard Helm,
Ralph Johnson, and John Vlissides
▪ Modularization
▪ Domain-Driven Design by Eric Evans Amanda Cinnamon
Amanda.cinnamon@daytonanalytics.com
www.thedevinstitute.com