如何使用dplyr以新列名作为字符串重命名选定的列 [英] How to rename selected columns using dplyr with new column names as strings

问题描述

我有以下小标题：

library(tidyverse)
df <- structure(list(Sepal.Length = c(5.1, 4.9, 4.7, 4.6, 5), Sepal.Width = c(3.5, 
3, 3.2, 3.1, 3.6), Petal.Length = c(1.4, 1.4, 1.3, 1.5, 1.4)), .Names = c("Sepal.Length", 
"Sepal.Width", "Petal.Length"), row.names = c(NA, 5L), class = c("tbl_df", 
"tbl", "data.frame"))

看起来像这样：

> df
# A tibble: 5 × 3
  Sepal.Length Sepal.Width Petal.Length
*        <dbl>       <dbl>        <dbl>
1          5.1         3.5          1.4
2          4.9         3.0          1.4
3          4.7         3.2          1.3
4          4.6         3.1          1.5
5          5.0         3.6          1.4

我要做的是替换 Sepal.Length 和带附加字符串 to_app<- .xxx 的Petal.Length 导致：

What I want to do is to replace Sepal.Length and Petal.Length with appended string to_app <- ".xxx" resulting in:

  Sepal.Length.xxx Sepal.Width Petal.Length.xxx
          5.1         3.5          1.4
          4.9         3.0          1.4
          4.7         3.2          1.3
          4.6         3.1          1.5
          5.0         3.6          1.4

我尝试了以下错误：

>df %>% rename(paste(Sepal.Length,to_app,sep="") = Petal.Length,paste(Sepal.Width,to_app,sep="") = Petal.Length)
Error: unexpected '=' in "df %>% rename(paste(Sepal.Length,to_app,sep="") ="

推荐答案

如果要使用dplyr的重命名函数，最好创建一个命名矢量/列表，并使用标准评估版中的 .dots 参数进行调用：

If you want to use dplyr's rename function, it would be best to create a named vector / list and call it using the .dots argument in the standard evaluation version:

cols <- c("Sepal.Length", "Petal.Length")
to_app <- ".xxx"
cols <- setNames(cols, paste0(cols, to_app))

df %>% rename_(.dots = cols)

## A tibble: 5 × 3
#  Sepal.Length.xxx Sepal.Width Petal.Length.xxx
#*            <dbl>       <dbl>            <dbl>
#1              5.1         3.5              1.4
#2              4.9         3.0              1.4
#3              4.7         3.2              1.3
#4              4.6         3.1              1.5
#5              5.0         3.6              1.4

但是请注意，此方法可能会随着dplyr的下一个版本0.6.0更改（请参见例如 http://blog.rstudio.org/2017/04/ 13 / dplyr-0-6-0-coming-soon / 和 http：// dplyr.tidyverse.org/articles/programming.html ）。

Note however, that this approach is subject to change with the next version 0.6.0 of dplyr (see e.g. http://blog.rstudio.org/2017/04/13/dplyr-0-6-0-coming-soon/ and http://dplyr.tidyverse.org/articles/programming.html).

这篇关于如何使用dplyr以新列名作为字符串重命名选定的列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IT屋！