CODEWITHSUNDEEP
rdplyr
thothal
thothal

Reputation: 20329

Using tidyr to select columns in a certain order given by a vector

I want to select certain columns in a data.frame with the select function from library(dplyr). The columns are given in a vector and I can use one_of() to do so:

library(dplyr)

ddf <- data.frame(A = 1:2, B = 2:1, C = LETTERS[1:2])
sel <- c("A", "C")

ddf %>% select(one_of(sel))
#   A C
# 1 1 A
# 2 2 B

I also can use also the form -one_of(.) to select everything but the given columns:

ddf %>% select(-one_of(sel))
#   B
# 1 2
# 2 1

But if I try to combine both, I get an unexpected result:

ddf %>% select(-one_of(sel), one_of(sel)) # works as expected
#   B A C
# 1 2 1 A
# 2 1 2 B

ddf %>% select(one_of(sel), -one_of(sel)) ## does not work as expected
# data frame with 0 columns and 2 rows

Is this behaviour intentional? And how can I bring my columns into a certain order with select without negating sel that is sel <- "B"would not be an option ;)

Upvotes: 3

Views: 790

Answers (1)

thothal
thothal

Reputation: 20329

As proposed by @[David Arenburg] the solution is to use:

ddf %>% select(one_of(sel), everything())

Upvotes: 2

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