如何根据R中另一个变量的频率计算一个变量的百分比

Question

我不确定如何写出来，但我会展示我想要的代码。我试图确定某些人在多次发生的任务中的准确性，但是，有很多案例。

names <- c("James", "James", "James", "James", "James", "John", "John", "Fred")
outcome <- c("successful", "unsuccessful", "unsuccessful", "successful", "successful", "successful",
         "unsuccessful", "unsuccessful")
accuracy <- c("60%", "60%", "60%", "60%", "60%", "50%", "50%", "0%")
df <- data.frame(names, outcome, accuracy)

在上面的例子中，我显然手动输入了数据，但我想知道如何编写代码来查看 successful/unsuccessful 结果与人名相关的频率，然后打印在准确度列中成功的实例总数的百分比。

我不太确定从哪里开始，希望这是一个我没想到的简单解决方案！

提前致谢

Answer 1

使用 ave.

df$accuracy <- NULL

df <- transform(df, accuracy=ave(outcome %in% "successful", names, 
                                 FUN=function(x) paste0(sum(x)/length(x)*100, "%")))
df
#   names      outcome accuracy
# 1 James   successful      60%
# 2 James unsuccessful      60%
# 3 James unsuccessful      60%
# 4 James   successful      60%
# 5 James   successful      60%
# 6  John   successful      50%
# 7  John unsuccessful      50%
# 8  Fred unsuccessful       0%

Answer 2

这个有用吗？

> df %>% group_by(names) %>% mutate(accuracy = paste0(100 * sum(outcome == 'successful')/n(),'%'))
# A tibble: 8 x 3
# Groups:   names [3]
  names outcome      accuracy
  <chr> <chr>        <chr>   
1 James successful   60%     
2 James unsuccessful 60%     
3 James unsuccessful 60%     
4 James successful   60%     
5 James successful   60%     
6 John  successful   50%     
7 John  unsuccessful 50%     
8 Fred  unsuccessful 0%

如何根据R中另一个变量的频率计算一个变量的百分比

How to calculate a percentage of one variable based on the frequency of another in R

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