Returning multiple objects in an R function [duplicate]
How can I return multiple objects in an R function? In Java, I would make a Class, maybe Person
which has some private variables and encapsulates, maybe, height
, age
, etc.
But in R, I need to pass around groups of data. For example, how can I make an R function return both an list of characters and an integer?
Unlike many other languages, R functions don't return multiple objects in the strict sense. The most general way to handle this is to return a list
object. So if you have an integer foo
and a vector of strings bar
in your function, you could create a list that combines these items:
foo <- 12
bar <- c("a", "b", "e")
newList <- list("integer" = foo, "names" = bar)
Then return
this list.
After calling your function, you can then access each of these with newList$integer
or newList$names
.
Other object types might work better for various purposes, but the list
object is a good way to get started.
Similarly in Java, you can create a S4 class in R that encapsulates your information:
setClass(Class="Person",
representation(
height="numeric",
age="numeric"
)
)
Then your function can return an instance of this class:
myFunction = function(age=28, height=176){
return(new("Person",
age=age,
height=height))
}
and you can access your information:
aPerson = myFunction()
aPerson@age
aPerson@height