Question

我想计算所有年龄段m的平均值和所有年龄段f的平均值，然后从原始值中减去它。

data <- data.frame(height=c(96,72,100,45),age=c(1,2,1,2),sex=c("m","f","f","m"))
data
    height age sex
1     96   1   m
2     72   2   f
3    100   1   f
4     45   2   m

期望的输出：

 data
    height age sex mean  dif
1     96   1   m    70.5  25.5
2     72   2   f    86     -14
3    100   1   f     86    14
4     45   2   m    70.5   -25.2

Answer 1

在dplyr中使用分组非常简单：

library(dplyr)

data %>% 
  group_by(sex) %>% 
  mutate(mean = mean(height),
         dif = height - mean)

Source: local data frame [4 x 5]
Groups: sex [2]

  height   age    sex  mean   dif
   <dbl> <dbl> <fctr> <dbl> <dbl>
1     96     1      m  70.5  25.5
2     72     2      f  86.0 -14.0
3    100     1      f  86.0  14.0
4     45     2      m  70.5 -25.5

如何总结类似的行？

1 个答案: