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
2
3
4
0
1
2
3

21.
1-based 0-based1
2
3
4
0
1
2
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