CODEWITHSUNDEEP
r
Beasterfield
Beasterfield

Reputation: 7113

Getting the name of a function

hopefully this is not too simple. I am looking for a function which gives me the name of a function, which I assigned to a variable. So something like

x <- mean
the_function_i_look_for(x)
[1] "mean"

Any ideas? Many thanks in advance!

Edit:

Ok, this is a more detailed example: Actually I have a function where I pass an arbitrary logarithm and which gives me a data.frame back. One column name of the data frame should indicate which logarithm was used.

> myFunction <- function( log, x ) {
    df <- data.frame( x, log(x))
    names(df) <- c(the_function_i_look_for(log), "x")
    return(df)
  }
> myFunction( log10, c(10,100,1000) )
>   log10    x
  1     1   10
  2     2  100
  3     3 1000

Upvotes: 1

Views: 161

Answers (1)

sgibb
sgibb

Reputation: 25736

You could use ?substitute:

myFunction <- function( log, x ) {
    df <- data.frame( x, log(x))
    names(df) <- c("x", substitute(log))
    return(df)
}

myFunction( log10, c(10,100,1000) )
#     x log10
#1   10     1
#2  100     2
#3 1000     3

EDIT: Seems to work for ReferenceClasses, too:

foo <- setRefClass("foo",
    methods = list(
    bar = function(x) {
        message("function: ", substitute(x))
    }
))

f <- foo$new()
f$bar(log)
# function: log
f$bar(mean)
# function: mean

Upvotes: 3

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