根据行的内容删除行

Question

我正在尝试编写一个代码，根据它的内容删除一个观察。其思想是，每一次观察都必须在初始/前期之后进行回顾。

我的数据框架如下所示：

ID  Type            Registered
P40 Pre-Initial     Yes
P40 Review  
P40 Review  
P42 Initial         Yes
P43 Initial         Yes
P43 Review  
P44 Pre-Initial     Yes
P44 Review  

我的dput代码：

tt <- structure(list(ID = c("P40", "P40", "P40", "P42", "P43", "P43",
                            "P44", "P44"),Type = c("Pre-Initial", "Review", "Review", "Initial", "Initial", "Review", "Pre-Initial", "Review"),
                     Registered = c("Yes", "", "", "Yes", "Yes", "", "Yes", "")),
                class = "data.frame", row.names = c(NA, -8L))

这是我想达到的目标：

ID  Type            Registered
P40 Pre-Initial     Yes
P40 Review  
P40 Review  
P43 Initial         Yes
P43 Review  
P44 Pre-Initial     Yes
P44 Review  

这是我到目前为止尝试过的代码，但它不起作用。

 tt %>% group_by(ID) %>%
    slice(which(Registered == "Yes" & any(Type != "Review")))
)

Answer 1

一种方法是简单地保留多于1行的组和条目Review，即

library(dplyr)

tt %>% 
 group_by(ID) %>% 
 filter(n() > 1 & any(Type == 'Review'))

Answer 2

每一次观察都必须在初始/前期之后进行一次回顾。

获取Type == "Review"的所有索引并提取它的最后一个索引，并将其与c("Pre-Initial", "Initial")索引进行比较，如果索引的any更大，则选择group。

library(dplyr)

tt %>%
  group_by(ID) %>%
  filter(any(tail(which(Type == "Review"), 1) > 
             which(Type %in% c("Pre-Initial", "Initial"))))

#  ID    Type        Registered
#  <chr> <chr>       <chr>     
#1 P40   Pre-Initial Yes       
#2 P40   Review      ""        
#3 P40   Review      ""        
#4 P43   Initial     Yes       
#5 P43   Review      ""        
#6 P44   Pre-Initial Yes       
#7 P44   Review      ""