如何將連續變量重新編碼為范圍

Question

我需要將連續變量重新編碼為類別，通常我使用“剪切”函數，但在剪切函數中我需要指定中斷。 我正在尋找一種方法，根據我的數據框中的其他分類變量，有一組不同的休息時間。

我的例子中的變量是Cost，“break”在第二個表“cost.range”中，我為每個“Region”和每個“Category”設置了一組不同的Breaks

示例：

Region    Product     Category Cost
Country A Product 1     CAT A  731
Country B Product 1     CAT A  659
Country C Product 1     CAT A  385
Country D Product 1     CAT A  763
Country A Product 2     CAT A  701
Country B Product 2     CAT A  759
Country C Product 2     CAT A  580
Country D Product 2     CAT A  147
Country A Product 3     CAT B  645
Country B Product 3     CAT B  657
Country C Product 3     CAT B  424


Region       Category  Cost.Range      Range
Country A      CAT A         10          R1
Country A      CAT A         50          R2
Country A      CAT A        200          R3
Country A      CAT A       1000          R4
Country A      CAT B         20          R1
Country A      CAT B        100          R2
Country A      CAT B        400          R3
Country A      CAT B       1500          R4

用於生成示例的代碼：

Region <- c("Country A","Country B","Country C","Country D","Country A","Country B","Country C","Country D","Country A","Country B","Country C","Country D","Country A","Country B","Country C","Country D")
Product <- c("Product 1","Product 1","Product 1","Product 1","Product 2","Product 2","Product 2","Product 2","Product 3","Product 3","Product 3","Product 3","Product 4","Product 4","Product 4","Product 4")
Category <- c("CAT A","CAT A","CAT A","CAT A","CAT A","CAT A","CAT A","CAT A","CAT B","CAT B","CAT B","CAT B","CAT B","CAT B","CAT B","CAT B")
Cost <- c(731,659,385,763,701,759,580,147,645,657,424,34,850,463,160,550)

Table1 <- data.frame(Region, Product, Category, Cost)

Region <- c("Country A","Country A","Country A","Country A","Country A","Country A","Country A","Country A")
Category <- c("CAT A","CAT A","CAT A","CAT A","CAT B","CAT B","CAT B","CAT B")
Cost.range <- c(10,50,200,1000,20,100,400,1500)
Range <- c("R1","R1","R3","R4","R1","R2","R3","R4")

Table2 <- data.frame(Region, Category, Cost.range, Range)

Answer 1

這不是最優雅的解決方案（我有興趣看到更好的方法），但它應該達到您正在尋找的結果。

dplyr包中的select()和distinct()函數可以找到Region和Category的可能組合。 這些組合用於對兩個表進行子集化，並將cut()函數應用於每個子集。

library('dplyr')
library('data.table')

dt1 <- data.table(Table1)
dt2 <- data.table(Table2)

t2d <- Table2 %>% select(Region, Category) %>% distinct

for(i in 1:nrow(t2d)){
  dt2_range_subset <- dt2[Region == as.character(t2d$Region[i]) 
                          & Category == t2d$Category[i], Cost.range]
  dt1[Region == as.character(t2d$Region[i]) & Category == t2d$Category[i],
      Cost_factor := cut(as.matrix(Cost), dt2_range_subset)]
}