CODEWITHSUNDEEP
rfunctionpurrr
Alex
Alex

Reputation: 2788

Use purrr::pmap_dfc to iterate through function and keep function names as headers

I am having difficulty getting my function names as headers in my final data frame after using purrr::pmap_dfc.

My final code has V1 and V2 as headers, but I would like my function names, add_1_times_multi and neg_1_times_multi, as headers. Below is a reprex.

library(tidyverse)
# define functions
add_1_times_multi <- function(vec, multi){(vec + 1) * multi}
neg_1_times_multi <- function(vec, multi){-(vec) * multi}

# put functions in list
my_functions <- function(vec,multi){
  list(
    add_1_times_multi(vec, multi),
    neg_1_times_multi(vec, multi)
  )
}

# define values
my_vector <- rnorm(n = 10, mean = 100, sd = 1)
multiplyr <- 3

# put values in list
l <- list(list(my_vector), multiplyr)

# purrr::pmap_dfc
pmap_dfc(l, my_functions)
#> # A tibble: 10 x 2
#>       V1    V2
#>    <dbl> <dbl>
#>  1  308. -305.
#>  2  305. -302.
#>  3  304. -301.
#>  4  304. -301.
#>  5  310. -307.
#>  6  304. -301.
#>  7  298. -295.
#>  8  300. -297.
#>  9  301. -298.
#> 10  305. -302.

Created on 2018-12-06 by the reprex package (v0.2.1)

As stated above I would like the final result to have add_1_times_multi and neg_1_times_multi as column names. Not V1 and V2.

Upvotes: 0

Views: 373

Answers (1)

prosoitos
prosoitos

Reputation: 7437

Your way to define your function is quite tortuous. Instead of creating 2 functions, then a 3rd function which makes a list of those functions, why not directly create a function which gives you what you want:

my_function <- function(vec, multi) {
  tibble(
    add_1_times_multi = (vec + 1) * multi,
    neg_1_times_multi = - vec * multi
  )
}

Also, since you only have 2 vectors as arguments to your function, you don't need pmap() and could simply use map2():

my_vector <- rnorm(n = 10, mean = 100, sd = 1)
multiplyr <- 3

map2_df(my_vector, multiplyr, my_function)

If you really want to use pmap():

l <- list(my_vector, multiplyr)

pmap_df(l, my_function)

Note that you don't need to pass my_vector in list() before passing it again in list() with multiplyr.

Upvotes: 3

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