RInterface package

1. What is R?
2. What is RInterface?
3. How does it work?

1. What is R?

R is a platform for statistical computing (https://www.r-project.org/). Algebraic statisticians may be interested in using both R and Macaulay2! Or algebraic geometers who teach a lot of undergraduate probability/statistics… :)

pnorm(1.96, lower.tail=FALSE)

There's already a library for running Macaulay2 code inside R:

citation("m2r")

library(m2r)
m2("R = QQ[x,y,z,w]")
m2("monomialCurveIdeal(R, {1, 2, 3})")

2. What is RInterface?

RInterface is a new Macaulay2 package that goes in the opposite direction, i.e., it allows us to run R code inside Macaulay2.

needsPackage "RInterface";
pnorm = RFunction "pnorm"
value pnorm(1.96, "lower.tail" => false)

2.1. RObject

The basic type is RObject, which can be converted to a Macaulay2 object with "value". Lots of methods are defined for RObjects.

needsPackage "RInterface";
RObject {1, 3/2, pi, ii}
value oo
2 + RObject 3
cos RObject pi
methods RObject

2.2. RFunction

Another type is RFunction, which wraps around an R function. It converts its inputs into the appropriate RObject.

needsPackage "RInterface";
qnorm = RFunction "qnorm"
qnorm \ {0.95, 0.975, 0.995}
ancestors class qnorm

2.3. RSymbol

RFunction's are constructed using RSymbol, which is a method that creates RObject's from symbol names. It is also useful for loading data sets.

needsPackage "RInterface";
RSymbol "iris"
value oo

3. How does it work?

Under the hood, RInterface uses the ForeignFunctions package to make calls to the R C API.

needsPackage "RInterface";
ancestors RObject
code (NewFromMethod, RFunction, RObject)
debug RInterface
class \ {PROTECT, lcons, UNPROTECT}