Question

假设我有一个格式如下的表格：

CowId    Farm    Week1
1        CB      c("Staphylococcus aureus", "Escherichia coli")
2        CB      No Growth
3        CB      NA
4        CB      Staphylococcus aureus

如何查看金黄色葡萄球菌是否为 Week1 列的成员？我试过了

dt.wide %>%
    filter(Week1 %in% "Staphylococcus aureus")

但它只捕获 CowId 4，而不捕获 CowId 1。任何反馈都会有所帮助。

dt.wide <- structure(list(CowId = c(1L, 2L, 3L, 4L), 
                          Farm = structure(c(1L, 1L, 1L, 1L), 
                          .Label = c("CB", "CB", "CB", "CB"), 
                          class = "factor"), 
                          Week1 = list(c("Staphylococcus aureus", "Escherichia coli"), "No Growth", NA, "Staphylococcus aureus")), 
                          row.names = c(NA, -4L), 
                          class = c("tbl_df", "tbl", "data.frame"))

Answer 1

基础 R 方法：

subset(dt.wide, sapply(Week1, function(x) "Staphylococcus aureus" %in% x))

#   CowId Farm  Week1    
#  <int> <fct> <list>   
#1     1 CB    <chr [2]>
#2     4 CB    <chr [1]>

Answer 2

如果您想检查 'Staphylococcus aureus' 是否是 Week1 列的成员而不保留列表中的内容。这种方法会奏效。

您首先unnest列，应用您的过滤器，如果您愿意，您可以随时再次嵌套：

library(tidyr)
library(dplyr)

df %>% 
  unnest(Week1) %>% 
  filter(Week1 %in% "Staphylococcus aureus")

检查项目是否在列表中

2 个答案: