我很難在使用dplyr的函數中重命名列。我已經在非標準評估和使用enquo上找到有用的帖子(例如,http://dplyr.tidyverse.org/articles/programming.html和Changing names of resulting variables in custom dplyr function)。最終目標是使用該函數來彙總每個組,然後將列重命名爲比原始變量名稱更有意義的內容。在dplyr 0.7+函數中重命名
下面是一個簡單的例子,它除了註釋掉的行之外都有效。
library(tidyverse)
myfunc <- function(df, groupvar, colvar, grouplab, collab) {
groupvar <- enquo(groupvar)
colvar <- enquo(colvar)
grouplab <- enquo(grouplab) # quo_name instead?
collab <- enquo(collab) # quo_name instead?
t <- df %>%
select(!!groupvar, !!colvar) %>%
group_by(!!groupvar, !!colvar) %>%
summarise(
Frequencies = length(!!colvar),
Percentages = length(!!colvar)/nrow(df)
) %>%
mutate(
Frequencies = scales::comma(Frequencies),
Percentages = scales::percent(Percentages)
) #%>%
# rename(
# (!!grouplab) = !!groupvar, # add a more descriptive grouping var label
# (!!collab) = !!colvar) # add a more descriptive column var label
# Error: unexpected '=' in: rename((!!grouplab) = "
... # code to create an xtable, print it into LaTeX
}
myfunc <- (df = mtcars, groupvar = gear, colvar = cyl, grouplab = "Vehicle Gears", collab = "Vehicle Cylinders")
# I purposely made grouplab and collab have a space in case that changes anything.
的功能之外,相關部分將簡單地寫着:mtcars <- mtcars %>% rename("Vehicle Cylinders" = cyl, "Vehicle Gears" = gear)
我必須重新命名的功能與它的外面是如何運作將得到絆倒。有什麼建議?我接受建議。
UPDATE
這是一種方法。我寧願不把變量名稱放在字符串中,但不知道在這裏繞過它。接受建議。
library(tidyverse)
library(xtable)
data(mtcars)
t_groupedfreqprop <- function(df, groupvar, colvar, grouplab, collab, plotname) {
groupvar2 <- rlang::sym(groupvar)
colvar2 <- rlang::sym(colvar)
grouplab <- rlang::sym(grouplab)
collab <- rlang::sym(collab)
t <- df %>%
select(!!groupvar2, !!colvar2) %>%
group_by(!!groupvar2, !!colvar2) %>%
summarise(
Frequencies = length(!!colvar2),
Percentages = length(!!colvar2)/nrow(df)
) %>%
mutate(
Frequencies = scales::comma(Frequencies),
Percentages = scales::percent(Percentages)
) %>%
rename(
!!grouplab := !!rlang::sym(groupvar2),
!!collab := !!rlang::sym(colvar2)
)
# remainder of function removed
}
t_groupedfreqprop(df = mtcars, groupvar = "gear", colvar = "cyl", grouplab = "Vehicle Gears", collab = "Vehicle Cylinders")
感謝,@Hong大井。這種技術是否仍然在一個函數中工作 - 也就是說,我沒有對新名稱進行硬編碼? – Daniel
是的,它應該可以工作,但是你必須使用'en''來引用'x'和'xnew',然後你可以Unquote。請參閱'dplyr'中的編程小插曲以瞭解* tidyeval *概念中的更多信息。 – cderv
謝謝。我仍然必須缺少一些東西......將函數沸騰到相關部分會引發錯誤:「錯誤:只能將字符串轉換爲符號。」這個小插圖有助於(https://cran.r-project.org/web/packages/rlang/vignettes/tidy-evaluation.html),但我仍然在如何在一個函數中工作。 t_groupedfreqprop < - 功能(DF,組變量,grouplab){ 組變量< - enquo(組變量) grouplab < - enquo(grouplab) 噸<- df %>% 重命名( !! grouplab:= !! rlang ::符號(groupvar)) } t_groupedfreqprop(df = mtcars,groupvar = gear,grouplab =「Vehicle Gears」) – Daniel