r语言 - 如何让分位数与summarise_at和group_by (dplyr) 一起工作



当使用dplyr创建按变量级别组织的汇总统计信息表时,我无法弄清楚计算四分位数的语法,而不必重复列名。也就是说,使用调用(如vars()list()(可以与其他函数(如mean()median()一起使用,但不能使用quantile()

搜索产生了过时的解决方案,这些解决方案不再有效,因为它们使用已弃用的调用,例如do()和/或funs()

data(iris)
library(tidyverse)
#This works: Notice I have not attempted to calculate quartiles yet
summary_stat <- iris %>% 
group_by(Species) %>% 
summarise_at(vars(Sepal.Length), 
list(min=min, median=median, max=max,
mean=mean, sd=sd)
)
A tibble: 3 x 6
Species      min median   max  mean    sd
<fct>      <dbl>  <dbl> <dbl> <dbl> <dbl>
1 setosa       4.3    5     5.8  5.01 0.352
2 versicolor   4.9    5.9   7    5.94 0.516
3 virginica    4.9    6.5   7.9  6.59 0.636
##########################################################################
#Does NOT work:
five_number_summary <- iris %>% 
group_by(Species) %>% 
summarise_at(vars(Sepal.Length),
list(min=min, Q1=quantile(.,probs = 0.25),
median=median, Q3=quantile(., probs = 0.75),
max=max))
Error: Must use a vector in `[`, not an object of class matrix.
Call `rlang::last_error()` to see a backtrace
###########################################################################
#This works: Remove the vars() argument, remove the list() argument,
#replace summarise_at() with summarise()
#but the code requires repeating the column name (Sepal.Length)
five_number_summary <- iris %>% 
group_by(Species) %>% 
summarise(min=min(Sepal.Length), 
Q1=quantile(Sepal.Length,probs = 0.25),
median=median(Sepal.Length), 
Q3=quantile(Sepal.Length, probs = 0.75),
max=max(Sepal.Length))
# A tibble: 3 x 6
Species      min    Q1 median    Q3   max
<fct>      <dbl> <dbl>  <dbl> <dbl> <dbl>
1 setosa       4.3  4.8     5     5.2   5.8
2 versicolor   4.9  5.6     5.9   6.3   7  
3 virginica    4.9  6.22    6.5   6.9   7.9

最后一段代码准确地生成了我正在寻找的内容,但我想知道为什么没有更短的语法不会强迫我重复变量。

在失败的summarise_at调用中,您缺少quantile函数前面的~。请尝试以下操作:

five_number_summary <- iris %>% 
group_by(Species) %>% 
summarise_at(vars(Sepal.Length),
list(min=min, Q1=~quantile(., probs = 0.25),
median=median, Q3=~quantile(., probs = 0.75),
max=max))
five_number_summary
# A tibble: 3 x 6
Species      min    Q1 median    Q3   max
<fct>      <dbl> <dbl>  <dbl> <dbl> <dbl>
1 setosa       4.3  4.8     5     5.2   5.8
2 versicolor   4.9  5.6     5.9   6.3   7  
3 virginica    4.9  6.22    6.5   6.9   7.9

您可以创建一个列表列,然后使用unnest_wider,这需要 tidyr 1.0.0

library(tidyverse)
iris %>% 
group_by(Species) %>% 
summarise(q = list(quantile(Sepal.Length))) %>% 
unnest_wider(q)
# # A tibble: 3 x 6
#   Species     `0%` `25%` `50%` `75%` `100%`
#   <fct>      <dbl> <dbl> <dbl> <dbl>  <dbl>
# 1 setosa       4.3  4.8    5     5.2    5.8
# 2 versicolor   4.9  5.6    5.9   6.3    7  
# 3 virginica    4.9  6.22   6.5   6.9    7.9

有一个names_repair的参数,但显然这会更改所有列的名称,而不仅仅是未嵌套的列(??

iris %>% 
group_by(Species) %>% 
summarise(q = list(quantile(Sepal.Length))) %>% 
unnest_wider(q, names_repair = ~paste0('Q_', sub('%', '', .)))
# # A tibble: 3 x 6
#   Q_Species    Q_0  Q_25  Q_50  Q_75 Q_100
#   <fct>      <dbl> <dbl> <dbl> <dbl> <dbl>
# 1 setosa       4.3  4.8    5     5.2   5.8
# 2 versicolor   4.9  5.6    5.9   6.3   7  
# 3 virginica    4.9  6.22   6.5   6.9   7.9

另一种选择是group_modify

iris %>% 
group_by(Species) %>% 
group_modify(~as.data.frame(t(quantile(.$Sepal.Length))))
# # A tibble: 3 x 6
# # Groups:   Species [3]
#   Species     `0%` `25%` `50%` `75%` `100%`
#   <fct>      <dbl> <dbl> <dbl> <dbl>  <dbl>
# 1 setosa       4.3  4.8    5     5.2    5.8
# 2 versicolor   4.9  5.6    5.9   6.3    7  
# 3 virginica    4.9  6.22   6.5   6.9    7.9

或者你可以使用data.table

library(data.table)
irisdt <- as.data.table(iris)
irisdt[, as.list(quantile(Sepal.Length)), Species]
#       Species  0%   25% 50% 75% 100%
# 1:     setosa 4.3 4.800 5.0 5.2  5.8
# 2: versicolor 4.9 5.600 5.9 6.3  7.0
# 3:  virginica 4.9 6.225 6.5 6.9  7.9

有关@arienrhod的最新版本的说明

library(dplyr,quietly = TRUE,verbose = FALSE, warn.conflicts = FALSE)
five_number_summary <- iris %>% 
group_by(Species) %>% 
summarise(across(Sepal.Length, list(min=min, Q1=~quantile(., probs = 0.25),
median=median, Q3=~quantile(., probs = 0.75),
max=max),  .names = "{.fn}"))
five_number_summary
#> # A tibble: 3 x 6
#>   Species      min    Q1 median    Q3   max
#>   <fct>      <dbl> <dbl>  <dbl> <dbl> <dbl>
#> 1 setosa       4.3  4.8     5     5.2   5.8
#> 2 versicolor   4.9  5.6     5.9   6.3   7  
#> 3 virginica    4.9  6.22    6.5   6.9   7.9

创建于 2022-02-21 由 reprex 软件包 (v2.0.1(

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