请考虑以下示例:
library(dplyr)
df <- data.frame(
Cat = c ("A","B","C","B","C","A","C","A","B"),
Fre = c(9,5,0,2,7,8,1,3,7))
我想要计算由变量Cat
分组的平均值,如下所示.
df_new <- df %>%
summarise(Mean = mean(Fre))
# A tibble: 3 × 2
Cat Mean
<chr> <dbl>
1 A 6.67
2 B 4.67
3 C 2.67
现在我的问题是:如何将计算出的平均值绑定到原始数据df
?我需要的输出如下所示;
Cat Fre Mean
1 A 9 6.67
2 B 5 4.67
3 C 0 2.67
4 B 2 4.67
5 C 7 2.67
6 A 8 6.67
7 C 1 2.67
8 A 3 6.67
9 B 7 4.67
提前谢谢您!