r - 基于另一列的 block 因子

Question

该示例显示了不同工厂的产量测量值， 第一列表示工厂 最后一列是生产量。

factory <- c("A","A","B","B","B","B","B","C","D")
production <- c(15, 2, 1, 1, 2, 1, 2,20,5)
df <- data.frame(factory, production)
df
  factory production
1       A         15
2       A          2
3       B          1
4       B          1
5       B          2
6       B          1
7       B          2
8       C         20
9       D          5

现在我想根据工厂在这个数据集中的总产量将这些工厂集中到更少的级别。

使用正常的 forcats::fct_lump，我可以根据它们出现的行数来合并它们，例如制作 3 个级别:

library(tidyverse)    
df %>% mutate(factory=fct_lump(factory,2))
      factory production
    1       A         15
    2       A          2
    3       B          1
    4       B          1
    5       B          2
    6       B          1
    7       B          2
    8   Other         20
    9   Other          5

但我想根据总和(产量)对它们进行汇总，保留前 n=2 家工厂(按总产量)并将其余工厂汇总。期望的结果:

1       A         15
2       A          2
3   Other          1
4   Other          1
5   Other          2
6   Other          1
7   Other          2
8       C         20
9   Other          5

有什么建议吗？

谢谢!

Answer 1

这里的关键是应用特定的理念，以便根据生产总和将工厂分组在一起。请注意，这种理念与您在(真实)数据集中的实际值有关。

选项 1

下面的示例将总产量等于或小于 15 的工厂组合在一起。如果你想要另一个分组，你可以修改阈值(例如使用 18 而不是 15)

factory <- c("A","A","B","B","B","B","B","C","D")
production <- c(15, 2, 1, 1, 2, 1, 2,20,5)
df <- data.frame(factory, production, stringsAsFactors = F)

library(dplyr)

df %>%
  group_by(factory) %>%
  mutate(factory_new = ifelse(sum(production) > 15, factory, "Other")) %>%
  ungroup()

# # A tibble: 9 x 3
#   factory production factory_new
#   <chr>        <dbl> <chr>      
# 1 A               15 A          
# 2 A                2 A          
# 3 B                1 Other      
# 4 B                1 Other      
# 5 B                2 Other      
# 6 B                1 Other      
# 7 B                2 Other      
# 8 C               20 C          
# 9 D                5 Other 

我正在创建 factory_new 而不删除(原始的)factory 列。

选项 2

这是一个示例，您可以根据工厂的产量对工厂进行排名/排序，然后您可以选择一些顶级工厂保持原样并将其余工厂分组

factory <- c("A","A","B","B","B","B","B","C","D")
production <- c(15, 2, 1, 1, 2, 1, 2,20,5)
df <- data.frame(factory, production, stringsAsFactors = F)

library(dplyr)

# get ranked factories based on sum production
df %>%
  group_by(factory) %>%
  summarise(SumProd = sum(production)) %>%
  arrange(desc(SumProd)) %>%
  pull(factory) -> vec_top_factories

# input how many top factories you want to keep
# rest will be grouped together
n = 2

# apply the grouping based on n provided
df %>%
  group_by(factory) %>%
  mutate(factory_new = ifelse(factory %in% vec_top_factories[1:n], factory, "Other")) %>%
  ungroup()

# # A tibble: 9 x 3
#   factory production factory_new
#   <chr>        <dbl> <chr>      
# 1 A               15 A          
# 2 A                2 A          
# 3 B                1 Other      
# 4 B                1 Other      
# 5 B                2 Other      
# 6 B                1 Other      
# 7 B                2 Other      
# 8 C               20 C          
# 9 D                5 Other