CODEWITHSUNDEEP
rdplyr
neversaint
neversaint

Reputation: 64004

How to concatenate dataframe produces by function that takes input from two vectors

I have the following functions that returns a tibble:


library(tidyverse)
process_data <- function(ky1 = "a", ky2 = "x") {

     l <- list( musician = c("John","Paul","George","Ringo"), 
                tools    = c("voice", "guitar", "bass", "drum")
                )
    df <- as.tibble(l) %>%
         mutate(first_key = ky1,second_key = ky2)
    return(df)
}

process_data()
#> # A tibble: 4 × 4
#>   musician  tools first_key second_key
#>      <chr>  <chr>     <chr>      <chr>
#> 1     John  voice         a          x
#> 2     Paul guitar         a          x
#> 3   George   bass         a          x
#> 4    Ringo   drum         a          x

Given two vectors 

ky1_vec <- c("a","b","c")
ky2_vec <- c("w","x","y","z")

I'd like to get one data frame/tibble for all combinations of the above list using process_data():

 musician  tools first_key second_key
     John  voice         a          w
     Paul guitar         a          w
   George   bass         a          w
    Ringo   drum         a          w
     John  voice         a          x
     Paul guitar         a          x
   George   bass         a          x
    Ringo   drum         a          x
    ...    ...          ...       ...
     John  voice         c          z
     Paul guitar         c          z
   George   bass         c          z
    Ringo   drum         c          z
  # total 3 * 4 * 4 = 48 rows

How can I do that?

Upvotes: 1

Views: 39

Answers (1)

akrun
akrun

Reputation: 887128

We can use map2_df

library(tidyverse)
d1 <- crossing(ky1_vec, ky2_vec)
map2_df(d1$ky1_vec, d1$ky2_vec, process_data)

Or another option is

expand.grid(ky1_vec = ky1_vec, ky2_vec = ky2_vec) %>% 
      rowwise() %>% 
      do(data.frame(process_data(.$ky1_vec, .$ky2_vec)))

With this result:

Source: local data frame [48 x 4]
Groups: <by row>

# A tibble: 48 × 4
   musician  tools first_key second_key
*     <chr>  <chr>    <fctr>     <fctr>
1      John  voice         a          w
2      Paul guitar         a          w
3    George   bass         a          w
4     Ringo   drum         a          w
5      John  voice         b          w
6      Paul guitar         b          w
7    George   bass         b          w
8     Ringo   drum         b          w
9      John  voice         c          w
10     Paul guitar         c          w
# ... with 38 more rows

Upvotes: 1

Related Questions