反转列中的值

Question

我的数据是这样的。我想反转 B 列的值。

df <- data.frame(A = c(  "Not at all"  ,"Several days" ,  "More than half the days",  "Nearly every day "),
                 B = c(1, 2, 3, 4))

所以，我想要这样。








df <- data.frame(A = c(  "Not at all"  ,"Several days" ,  "More than half the days",  "Nearly every day "),
                 B = c(4, 3, 2, 1))

rev 不适用于我的数据，数据结构为：

'data.frame':   511 obs. of  6 variables:
 $ id...1          : int  1 2 3 4 5 6 7 8 9 10 ...
 $ Q3.2_1...2      : num  1 3 2 2 2 2 2 2 3 2 ...
 $ id...3          : int  1 2 3 4 5 6 7 8 9 10 ...
 $ Q3.2_1...4      : chr  "Several days" "Not at all" "Not at all" "Nearly every day" ...
 $ newcolumn.id    : int  1 2 3 4 5 6 7 8 9 10 ...
 $ newcolumn.Q3.2_1: chr  "Several days" "Not at all" "Not at all" "Nearly every day"

我要倒Q3.2_1 num.

Answer 1

试试这个：

#Code
df$B <- rev(df$B)

输出：

df
                        A B
1              Not at all 4
2            Several days 3
3 More than half the days 2
4       Nearly every day  1

或 dplyr:

library(dplyr)
#Code
df <- df %>% mutate(B=rev(B))

反转列中的值

Reversing values in a column

reverse

r

dplyr