R 总结多个函数

Question

我有一个数据框架，在该数据框架下按县进行分组，然后尝试使用跨越跨的数据来汇总其余数据。 Some of the variables I would like to sum across, while other variables I would like to average across

Here is my sample data:

dat <- data.frame("county" = c("a", "a", "b", "b", "c", "c"), 
                 "pop" = c(10,20,30,40, 40, 20),
                 "men" = c(5, 15, 15, 25, 15, 10),
                 "crime_rate"= c(4,3, 2, 1, 6, 2),
                 "rate_2" = c(1, 2, 1, 4, 3, 10))

here is what I've tried

dat_summary <- dat %>%
  group_by(county) %>%
  summarise(across(c(pop, men), sum)) %>%
  summarise(across(c(crime_rate, rate_2), average))

I know that summarise(across) works if I were to just sum the population or男人的人数，如果我只是尝试找到平均费率的平均值，也将有效 - 但是我如何才能使我既可以工作并为我提供所需信息的摘要数据框架？

我能想到的唯一方法是为总和变量创建一个数据框架分组并汇总，然后重复平均变量，然后将所有变量重复在一起。

我有没有办法在一个代码序列中完成这一切？谢谢！ *注意：我与之合作的价格是N/100,000，因此在这种情况下，平均值将工作。

Answer 1

只要按组变量保持恒定，我们就可以在（）函数中包含多个函数summarize（）使用不同的函数来总结变量的子集输入数据框。

dat <- data.frame("county" = c("a", "a", "b", "b", "c", "c"), 
                  "pop" = c(10,20,30,40, 40, 20),
                  "men" = c(5, 15, 15, 25, 15, 10),
                  "crime_rate"= c(4,3, 2, 1, 6, 2),
                  "rate_2" = c(1, 2, 1, 4, 3, 10))
library(dplyr)

dat_summary <- dat %>%
     group_by(county) %>%
     summarise(across(c(pop, men), sum), 
     across(c(crime_rate, rate_2), mean))

...和输出：

> dat %>%
+      group_by(county) %>%
+      summarise(across(c(pop, men), sum), 
+      across(c(crime_rate, rate_2), mean))
# A tibble: 3 × 5
  county   pop   men crime_rate rate_2
  <chr>  <dbl> <dbl>      <dbl>  <dbl>
1 a         30    20        3.5    1.5
2 b         70    40        1.5    2.5
3 c         60    25        4      6.5
>