在如何根据我的函数中的Vector合并数据帧行的重新排序时遇到了困难

library(tidyverse)
library(ggplot2) for diamonds dataset

我无法让我的功能发挥作用.我正在尝试使用此示例中的钻石数据集形式ggplot2,是dplyr :: group_by“cut”和“color”,然后dplyr :: summarize来获取计数.我使用rlang和purrr将两个计数摘要输出到列表中,然后重命名其中一个列,并用dplyr :: map_df绑定它们.最后,我想根据另一个名为“Order”的向量重新排序“Cut”列.该函数有效,直到我尝试合并行重新排序…

这可能对这些数据没有意义,但这仅仅是一个例子,它对我的真实数据有意义.

无论如何,下面的代码工作……

Groups<-list("cut","color")

 Groups<-Groups%>%
 map_df(function(group){

     syms<-syms(group)

     diamonds%>%
         group_by(!!!syms)%>%
         summarise(Count=n())%>%
         set_names(c("Cut","Count"))
 })

接下来,我想根据“Order”向量重新排序行,这也适用.

Order<-c("Good","Very Good","Premium","Ideal","Fair","E","F","G","D","H","J","I")

Groups%>%slice(match(Order, Cut))

但是,这就是我被困住的地方.我试图在一个函数中完成所有这些,但它似乎不起作用.我觉得我错过了一些小事……

Fun<-function(df){

Order<-c("Good","Very Good","Premium","Ideal","Fair","E","F","G","D","H","J","I")

Groups<-list("cut","color")

 Groups<-Groups%>%
 map_df(function(group){

     syms<-syms(group)

     df%>%
         group_by(!!!syms)%>%
         summarise(Count=n())%>%
         set_names(c("Cut","Count"))%>%
         slice(match(Order,Cut))
return(df)
})
}

这是另一种尝试……

Fun<-function(df){

Order<-c("Good","Very Good","Premium","Ideal","Fair","E","F","G","D","H","J","I")

Groups<-list("cut","color")

 Groups<-Groups%>%
 map_df(function(group){

     syms<-syms(group)

     df%>%
         group_by(!!!syms)%>%
         summarise(Count=n())%>%
         set_names(c("Cut","Count"))

df<-df%>%slice(match(Order,Cut))
return(df)
})
}

我在这里错过了什么？

最佳答案

我们不需要在循环中应用syms.它可以采用长度大于1的向量/列表并将其转换为符号.因此,循环遍历syms然后使用map在每个符号对象上执行group_by

Fun<-function(df){

Order<-c("Good","Very Good","Premium","Ideal","Fair","E","F","G","D","H","J","I")

Groups<-list("cut","color")

Groups %>%
       syms %>%
       map_df(~ df %>%
               group_by(!!!  .x) %>%
               summarise(Count=n()) %>%
               set_names(c("Cut","Count")) %>%
               slice(match(Order,Cut)) #%>%                    
               #mutate(Cut = as.character(Cut)) 
               #to avoid the warning coercion of factor to character 


      )




}

Fun(diamonds)
# A tibble: 12 x 2
#   Cut       Count
#   <chr>     <int>
# 1 Good       4906
# 2 Very Good 12082
# 3 Premium   13791
# 4 Ideal     21551
# 5 Fair       1610
# 6 E          9797
# 7 F          9542
# 8 G         11292
# 9 D          6775
#10 H          8304
#11 J          2808
#12 I          5422