As presented at JavaOne 2013

1. Data Science With R
~ for ~
Java Developers
@Sander_Mak

2. Agenda
Data Science
The R language
Gimme some Java!
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3. 90% of the world’s data was
produced in the last 2 years
- SINTEF/ScienceDaily June 2013!!!!!!!!
We need more than
just CRUD

4. Stand back.
I know Data Science!

5. Software
Engineering
Domain
Expertise
Math &
Statistics
Data
Science
Machine
Learning
Operations
Research
Danger!
Perl ahead!

6. Software
Engineering
Domain
Expertise
Math &
Statistics
Data
Science
Machine
Learning
Operations
Research
Danger!
Perl ahead!

7. Data Science:
Achievement Unlocked

8. R, R-Studio
Today
Data Science:
Achievement Unlocked

9. Agenda
Data Science
The R language
Gimme some Java!
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10. Language
Designers
Statisticians

11. Language
Designers?
Statisticians?
The best thing about R is that it was developed by statisticians. The
worst thing about R is that... it was developed by statisticians.
- Bo Cowgill, Google

12. Why R, then?
Open Source
De-facto standard (in statistical research)
“It’s a DSL posing as general purpose language”
Interactive data exploration

13. Why not R, then?
Slow
Memory Bound
(Did I mention it’s a quirky language?)
Try googling for R...

14. Why not R, then?
‘If you are using R and you think
you’re in hell, this is a map for you.’
- The R Inferno
Slow
Memory Bound
(Did I mention it’s a quirky language?)
Try googling for R...

15. Apparently, statisticians aren’t designers, either...

16. VS

17. Dynamic (eval)
Interpreted
Static types
Compiled
Functional/OO/Procedural OO

18. Factor Enum
numeric
character String
Integer/Double/...

19. Factor Enum
numeric
character String
vector
list
dataframe
Integer/Double/...

20. 1-based 0-based1
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21. 1-based 0-based1
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3
for-loops
higher-order functions
sapply(vec, function(elm) {
elm + 1;
})

22. eager evalutationlazy evaluation

23. eager evalutationlazy evaluation
pass-by-value
(copy-on-write)
pass-by-reference
Function F
Value A Value A
Value A’
call F(A) modify

24. Studio

25. Central
Comprehensive
R
Archive
Network
Studio

26. Coding time!

27. Titanic Competition:
Machine Learning from Disaster

28. Titanic Competition:
Machine Learning from Disaster

29. Titanic Competition:
Machine Learning from Disaster
Sex == Female
Decision Tree
Age > 50Age > 16
Fare > 100
T FT T F

30. Titanic Competition:
Machine Learning from Disaster
Sex == Female
Decision Tree
Age > 50Age > 16
Random Forest
Fare > 100
T FT T F
T
FT T FT
FT T F
T
FT T FT
FT T F

31. Demo time!

32. ...
...

33. Agenda
Data Science
The R language
Gimme some Java!
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34. Bridging R and Java
Integrate
Assimilate
Replace

35. rJava & Java/R interface
Integrate
Two way native interface
- JNI: libjri
- or TCP to RServe
Rengine re = new Rengine(new String[] {}, false, null);
// wait until engine is ready
if (!re.waitForR()) {
throw new IllegalStateException(“Can’t load R engine”);
}
re.eval("data(cars)", false);
REXP cars = re.eval("cars");
RVector carsVector = cars.asVector();
// dissect carsVector...

36. Assimilate
Reimplementation of R on JVM
Fast & lean
Parallelized
Just-another-lib
... not production ready yet...

37. Assimilate
// create a script engine manager
ScriptEngineManager factory =
new ScriptEngineManager();
// create an R engine
ScriptEngine engine =
factory.getEngineByName("Renjin");
// load package from classpath
engine.eval(“library(survey)");
// evaluate R code from String
engine.eval("print('Hello from R')");
Reimplementation of R on JVM
Fast & lean
Parallelized
Just-another-lib
... not production ready yet...

38. Reimplementation of R on JVM
Share data:
Integer[] data = {1, 2, 3};
engine.put("data", data);
engine.eval("print(sum(data))");
Assimilate

39. Reimplementation of R on JVM
Share data:
import(com.foo.User)
# instantiate Java beans
tim <- User$new(name='Tim', age=23)
tom <- User$new(name='Tom', age=45)
# invoke setter
tim$name <- "Timmy"
Use Java from Renjin:
Integer[] data = {1, 2, 3};
engine.put("data", data);
engine.eval("print(sum(data))");
Assimilate

40. Big Data?

41. Replace
JVM Libraries/platforms

42. Replace
Scalable R distributions
(non-JVM)
Revolution Analytics
Oracle Enterprise R

43. Wrap-up
Data Science
The R language
Gimme some Java!
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44. Sanitize
Explore
Model Predict
Scale

45. Next steps
Computing for Data Analysis
starts Sept. 23rd
Install R Read

46. Questions?
Data Science
The R language
Gimme some Java!
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@Sander_Mak
branchandbound.net