How to get lapply to output 2 objects obtained from a function

Question

I'm trying to lapply a function over a list. Because my function intends to output 2 objects, I'm running into a problem. For each item in the list, running the function only outputs results from the second object.

Here is a vastly simplified example.

test<-function(x){
  a<-x+4
  b<-x/34
}
list<-c(3,4,5,6,6)
lapply(list,test)

# Outputs b:
[[1]]
[1] 0.08823529

[[2]]
[1] 0.1176471

[[3]]
[1] 0.1470588

[[4]]
[1] 0.1764706

[[5]]
[1] 0.1764706

How to I get the function to output both a and b?

In your test function, add a third line: return(a = a, b = b) — Benjamin
– Benjamin, Commented Jan 27, 2016 at 16:44
@Benjamin - You mean return(c(a = a, b = b)) (or list depending on preference). But return() is a bit pointless on the last line, just c(a = a, b = b) would be fine. — Rich Scriven
– Rich Scriven, Commented Jan 27, 2016 at 16:53
oops. I meant to put that in list, actually. as in return(list(a=a, b=b)) — Benjamin
– Benjamin, Commented Jan 27, 2016 at 16:54

uselessconquest · Accepted Answer · 2016-01-27 16:49:28Z

3

The function is returning just the last line as it should. Try:

test<-function(x){
a<-x+4
b<-x/34
return(c(a,b))
}
list<-c(3,4,5,6,6)
lapply(list,test)

answered Jan 27, 2016 at 16:49

uselessconquest

766 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to get lapply to output 2 objects obtained from a function

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related