This document discusses integrating R and Scala. It provides context on existing packages like jvmr that allow calling Scala from R and Renjin, which implements an R interpreter in the JVM. It notes challenges like running the Scala compiler at runtime when calling Scala from R and issues with Renjin only working on Linux and requiring looking at GCC internals. The author advocates a simple approach of just adding JAR files to allow calling R from Scala but notes it is slow. The conclusion states that living between the two worlds can be funny.

1. R / Scala
Ruslan Shevchenko!
ruslan@Shevchenko.Kiev.UA!
!
@rssh1 !
https://github.com/rssh

2. R/Scala interpolation: Why ?
❖ Packages !
❖ for near any thing in statistics exists
appropriative R package. !
❖ Culture!
❖ math-centric community!
❖ quick evaluation. !
❖ more research than development !
❖ Fun!
❖ cross two nontrivial (and very funny)
languages

3. R/Scala: context
ScalaNLP:!
Breeze: + something in REPL
scala-centric point of view
• build environment!
• enhanched REPL + graphics!
• wait until math people switch to one ;)))!
• better port only things which will live in
process mode.

4. R/Scala :context
R is beautiful More like human language than computer!
• 40 years of history!
• parts in C and FORTRAN!
• functional, immutability, lazy evaluation!
• antic implementation, crazy conventions !
• Object systems:!
• S3, S4, R5, R-proto!
All live together ;)
R is ugly!
• Slow!
• programming ‘in large’ in hard.

5. R/JVM
❖ jvmr : !
❖ http://cran.r-project.org/web/packages/jvmr/index.html!
(David B. Dahl )!
❖renjin:!
❖ http://www.renjin.org/ (BeDataDriven)!
❖ fastr: !
❖ https://github.com/allr/fastr (Oracle)

6. JVMR
R
JVM
JVM
IPC
Scala interpreter in R
R interpreter in Scala

7. Simple, just add jar
unmanagedJars in Compile += {
import scala.sys.process._
val jarPath = List(“R","--slave","-e",
"""library("jvmr"); cat(.jvmr.jar)”""
).!!.trim
file(jarPath)
}
!

8. JVMR
Slow, run scala compiler in runtime!
if we want to call scala from R!
!
Integration via ‘string’ representations!
Very simple, in many cases it’s enough!
!
‘native’ R

9. RENJIN
❖ R interpeter in JVM!
❖ compiler toolchain for C and FORTRAN parts!
❖ gcj - based.!
❖ work only on linux.!
❖ R package with C parts => jar

10. RENJIN
Integration: JSR238 (javax.scripting)
java(scala) objects <=> R objects
Problems:
• Incomplete!
• Sometimes you need to look at gcc internals

11. Scala/R - import world.
OO - want one banana: !
get all with gorilla behind
If you live in two worlds, this is funny
Thanks for attention