dplyr::select
results in a data.frame, is there a way to make it return a vector if the result is one column?
Currently, I have to do extra step (res <- res$y
) to convert it to vector from data.frame, see this example:
#dummy data
df <- data.frame(x = 1:10, y = LETTERS[1:10], stringsAsFactors = FALSE)
#dplyr filter and select results in data.frame
res <- df %>% filter(x > 5) %>% select(y)
class(res)
#[1] "data.frame"
#desired result is a character vector
res <- res$y
class(res)
#[1] "character"
Something as below:
res <- df %>% filter(x > 5) %>% select(y) %>% as.character
res
# This gives strange output
[1] "c(\"F\", \"G\", \"H\", \"I\", \"J\")"
# I need:
# [1] "F" "G" "H" "I" "J"
The best way to do it (IMO):
library(dplyr)
df <- data_frame(x = 1:10, y = LETTERS[1:10])
df %>%
filter(x > 5) %>%
.$y
In dplyr 0.7.0, you can now use pull():
df %>% filter(x > 5) %>% pull(y)