15

INTERFACING R TO OTHER LANGUAGES

R is a great language, but it can’t do every-

thing well. Thus, it is sometimes desirable

to call code written in other languages from

R. Conversely, when working in other great lan-

guages, you may encounter tasks that could be better

done in R.

R interfaces have been developed for a number of other languages,

from ubiquitous languages like C to esoteric ones like the Yacas computer

algebra system. This chapter will cover two interfaces: one for calling

C/C++ from R and the other for calling R from Python.

15.1 Writing C/C++ Functions to Be Called from R.................................

You may wish to write your own C/C++ functions to be called from R. Typ-

ically, the goal is performance enhancement, since C/C++ code may run

much faster than R, even if you use vectorization and other R optimization

techniques to speed things up.

Another possible goal in dropping down to the C/C++ level is special-

ized I/O. For example, R uses the TCP protocol in layer 3 of the standard

Internet communication system, but UDP can be faster in some settings.