CODEWITHSUNDEEP
rdplyr
boot-scootin
boot-scootin

Reputation: 12515

Iterate through columns in dplyr?

df <- data.frame(col1 = rep(1, 15),
                  col2 = rep(2, 15),
                  col3 = rep(3, 15),
                  group = c(rep("A", 5), rep("B", 5), rep("C", 5)))

for(col in c("col1", "col2", "col3")){
   filt.df <- df %>%
     filter(group == "A") %>%
     select(group, col)
     # do other things, like ggplotting
 }

Error: All select() inputs must resolve to integer column positions. The following do not: * col

How can I iterate through a specific vector of columns using dplyr? I know I would use something like df[[col]] in base R, but am unfamiliar with how to do it in dplyr.

Upvotes: 2

Views: 6363

Answers (2)

dez93_2000
dez93_2000

Reputation: 1863

select_ and other underscore alternatives are now depreciated in dplyr. One should now use select(group, .data[[col]]). See the programming vignette in dplyr help for more.

Upvotes: 2

Wietze314
Wietze314

Reputation: 6020

this should work. I use the select_() function

library(dplyr)

df <- data.frame(col1 = rep(1, 15),
                 col2 = rep(2, 15),
                 col3 = rep(3, 15),
                 group = c(rep("A", 5), rep("B", 5), rep("C", 5)))

for(col in c("col1", "col2", "col3")){
  filt.df <- df %>%
    filter(group == "A") %>%
    select_(.dots = c('group', col))
  # do other things, like ggplotting
  print(filt.df)
}

Upvotes: 5

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