将包含逗号分隔的字符串值的列拆分为 R 中的新标题列

Question

我有一个数据框，其中一列包含字符串，用逗号分隔。我想知道是否有一种有效的方法可以将这些逗号分隔的值转换为新的列标题，如果这些新列值是原始行的一部分，则将它们设为二进制。我的数据样本可以复制如下：

data <- structure(list(id = c(6901257L, 6304928L, 7919400L), amenities = 
c("Wireless Internet,Air conditioning,Kitchen,Heating,Family/kid 
friendly,Essentials,Hair dryer,Iron,translation missing: 
en.hosting_amenity_50",  "Wireless Internet,Air 
conditioning,Kitchen,Heating,Family/kid friendly,Washer,Dryer,Smoke 
detector,Fire extinguisher,Essentials,Shampoo,Hangers,Hair 
dryer,Iron,translation missing: en.hosting_amenity_50",  "TV,Cable 
TV,Wireless Internet,Air 
conditioning,Kitchen,Breakfast,Buzzer/wireless 
intercom,Heating,Family/kid friendly,Smoke detector,Carbon monoxide 
detector,Fire extinguisher,Essentials,Shampoo,Hangers,Hair 
dryer,Iron,Laptop friendly workspace,translation missing: 
en.hosting_amenity_50" )), .Names = c("id", "amenities"), class = 
"data.frame", row.names = c(NA,  3L))

我有一个低效的方法来产生我的结果，就是把数据变成长格式，然后在reshape2中使用dcast。这种低效的方法可以通过以下方式重现：

data.long <- data %>%
mutate(amenities = strsplit(as.character(amenities), ",")) %>%
unnest(amenities)

data.long$amenities.value <- 1

data.wide <- reshape2::dcast(data.long, id ~ amenities, value.var = 
"amenities.value") #desired result

有没有更有效的方法从原始数据结构中得到想要的结果？

Answer 1

这是使用库 splitstackshape 的一种方法：

library(splitstackshape) 
library(tidyverse)

cSplit(df,  "amenities", sep = ",", direction = "long") %>%
  mutate(value = 1) %>%
  spread(amenities, value) -> df.wide

all.equal(df.wide, data.wide)
#TRUE

根据@A5C1D2H2I1M1N2O1R2T1，一个更密集、更快的解决方案是

cSplit_e(data, "amenities", ",", mode = "binary", type = "character", drop = TRUE)

Answer 2

仅使用 tidyverse

library(tidyverse)
data %>% 
  separate_rows(amenities, sep = ",") %>% 
  table() %>% 
  data.frame() %>% 
  spread(amenities,Freq)