问题描述
在 R 中,我想重命名所有以某个前缀开头的列(比如 "oldprefix1", "oldprefix2", "oldprefix3", ...
到 "newprefix1","newprefix2", "newprefix3", ...
) 在一个函数中.以下代码有效:
In R, I want to rename all the columns that starts with some prefix (say "oldprefix1", "oldprefix2", "oldprefix3", ...
to "newprefix1", "newprefix2", "newprefix3", ...
) inside a function. The following code works:
change = function(df) {
select(df, newprefix = starts_with('oldprefix') )
}
change(test)
但是,我想将带有新前缀的字符串作为参数传递给函数:
But, I would like to pass a string with the new prefix as parameter to the function:
change2 = function(df, prefix) {
dots = paste0(prefix," = starts_with('oldprefix')"
select_(df, dots)
}
change2(test, "newprefix")
我曾尝试使用 select_()
和 .dots
,但我无法将其与 starts_with()
函数一起使用.我收到错误 Error in eval(expr, envir, enclos) :找不到函数starts_with"
.
I have tried using select_()
and .dots
, but I cannot get it to work together with the starts_with()
function. I get the error Error in eval(expr, envir, enclos) : could not find function "starts_with"
.
推荐答案
可以选择使用 rename_at
mtcars %>%
rename_at(vars(starts_with('m')), funs(paste0('prefix', .)))
要更改旧名称,请使用 sub
For changing an old name, use sub
change2 <- function(df, oldpref, newpref) {
df %>%
rename_at(vars(starts_with(oldpref)), funs(sub(oldpref, newpref, .)))
}
change2(mtcars, "m", "newprefix") %>%
names
#[1] "newprefixpg" "cyl" "disp" "hp" "drat"
#[6] "wt" "qsec" "vs" "am" "gear"
#[11] "carb"
这篇关于使用 `starts_with()` 重命名列,其中新前缀是一个字符串的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!