CODEWITHSUNDEEP
rdplyr
Bourg
Bourg

Reputation: 43

For loop with dplyr package

I want to make this for loop for each colname in my dataframe but I have an error with group_by method :

Error in usemethod("group_by_") : no applicable method for 'group_by_' applied to an object of class "character"

My code : 

for(i in colnames(creditDF)){
 distribution <- creditDF %>%
  group_by(i) %>%
  summarise(value = n()) %>%
  select(label = i, value)

 print(distribution)
}

How can I fix this error?

Thanks for your help.

Upvotes: 0

Views: 2811

Answers (3)

Gregory Demin
Gregory Demin

Reputation: 4846

Solution with base R. 

for(i in creditDF) print(as.data.frame(table(i)))

Upvotes: 0

Kevin Arseneau
Kevin Arseneau

Reputation: 6264

I offer a more tidy alternative that creates a frequency table by column and binds them in a single data frame.

library(dplyr)
library(purrr)

mtcars %>%
  map(~table(.x)) %>%
  lapply(as_tibble) %>%
  bind_rows(.id = "var")

# # A tibble: 171 x 3
#     var    .x     n
#   <chr> <chr> <int>
# 1   mpg  10.4     2
# 2   mpg  13.3     1
# 3   mpg  14.3     1
# 4   mpg  14.7     1
# 5   mpg    15     1
# 6   mpg  15.2     2
# 7   mpg  15.5     1
# 8   mpg  15.8     1
# 9   mpg  16.4     1
# 10  mpg  17.3     1
# # ... with 161 more rows

Upvotes: 2

R Thomas
R Thomas

Reputation: 156

If I’m understanding your code correctly You want to find out the unique items in each column in your data frame and print the table to the console

for(i in colnames(creditDF)){
 distribution <- creditDF %>%
  group_by_at(.vars = i) %>%
  summarise(value = n())

 print(distribution)
}

Upvotes: 0

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