R中的gather()函数

Question

我最近刚开始学习R，在尝试使用gather函数时遇到了一个问题。当我将数据帧从宽转换为长时，如何使用gather() fxn来生成包含两列以上的数据帧。

例如下面的代码：

long_iris <- gather(head(iris, 3), "Col_1", "Col_2", "Col_3", "Col_4", "Col_5",1:5)

输出此错误消息：

> long_iris <- gather(head(iris, 3), "Col_1", "Col_2", "Col_3", "Col_4", "Col_5",1:5)
Error: Can't subset columns that don't exist.
x Column `Col_3` doesn't exist.
Run `rlang::last_error()` to see where the error occurred.

Answer 1

使用首选tidyr::pivot_longer

tidyr::pivot_longer(head(iris, 3), -Species)
# # A tibble: 12 x 3
#    Species name         value
#    <fct>   <chr>        <dbl>
#  1 setosa  Sepal.Length   5.1
#  2 setosa  Sepal.Width    3.5
#  3 setosa  Petal.Length   1.4
#  4 setosa  Petal.Width    0.2
#  5 setosa  Sepal.Length   4.9
#  6 setosa  Sepal.Width    3  
#  7 setosa  Petal.Length   1.4
#  8 setosa  Petal.Width    0.2
#  9 setosa  Sepal.Length   4.7
# 10 setosa  Sepal.Width    3.2
# 11 setosa  Petal.Length   1.3
# 12 setosa  Petal.Width    0.2