将代码从基数R转换为dplyr，特别是添加变量

Posted 2023-01-18

我正在尝试向数据集“ birth_data”添加一个名为“ state_color”的新变量。我想使用dplyr简化代码，但不确定如何转换。我知道在R底下看起来像这样：

red <- c("AK","ID","KS","NE","ND","OK","UT","WY","TX","AL","MS","SC","MT","GA","MO","LA","TN","AK","KY","AZ","WV") 
purple <- c("NC","VA","FL","OH","CO","NV","IN","IA","NM")
blue <- c("NH","PA","CA","MI","IL","MA","DE","NJ","CT","VT","ME","WA","OR","WI","NY","MA","RI","HI","MN","DC")
#assigning states to their respective color

birth_data$state_color[birth_data$state %in% red] <- "red"
birth_data$state_color[birth_data$state %in% purple] <- "purple"
birth_data$state_color[birth_data$state %in% blue] <- "blue"
head(birth_data)

我尝试对dplyr进行相同操作

red <- c("AK","ID","KS","NE","ND","OK","UT","WY","TX","AL","MS","SC","MT","GA","MO","LA","TN","AK","KY","AZ","WV") 
purple <- c("NC","VA","FL","OH","CO","NV","IN","IA","NM")
blue <- c("NH","PA","CA","MI","IL","MA","DE","NJ","CT","VT","ME","WA","OR","WI","NY","MA","RI","HI","MN","DC")
#assigning states to their respective color

birth_data %>%
  mutate(state_color <- c("red","purple","blue"))

但随后得到错误

错误：列state_color <- c("red", "purple", "blue")的长度必须为1103629（行数）或一个，而不是3

我在做什么错？

答案

您想从数据集开始，进行变异以创建一个新列，然后使用“ case_when”。如果所有情况均失败，则使用TRUE值。

red <- c("AK","ID","KS","NE","ND","OK","UT","WY","TX","AL","MS","SC","MT","GA","MO","LA","TN","AK","KY","AZ","WV") 
purple <- c("NC","VA","FL","OH","CO","NV","IN","IA","NM")
blue <- c("NH","PA","CA","MI","IL","MA","DE","NJ","CT","VT","ME","WA","OR","WI","NY","MA","RI","HI","MN","DC")

birth_data %>%
   mutate(state_color =case_when(
       state %in% red  ~ "red",
       state %in% purple  ~ "purple",
       state %in% blue  ~ "blue",
       TRUE ~ "no color"
  ))

另一答案

尝试一下：

出生数据％>％mutate（state_color = if_else（状态％in％红色，“红色”，if_else（状态％in％紫色，“紫色”，“蓝色”））

另一答案

如果您要从基数扩展，也应该查看data.table：>

library(data.table)

dt_states <- data.table(state = state.abb)

dt_states[state %in% red, state_color := 'red']
dt_states[state %in% blue, state_color := 'blue']
dt_states[state %in% purple, state_color := 'purple']

dt_states