组限制连接到行

Question

有人可以提供建议如何解决以下问题：

在每个ID的行上进行串联，但限制是仅考虑ID的类型流中至少有一个type = C的情况：

ID<-c(1,1,1,1,2,2,2,2,3,3)
type<-c("A","B","C","D","A","B","C","D","A","D")
mydata<-as.data.frame(cbind(ID,type))

Answer 1

library(dplyr) 
mydata %>% group_by(ID) %>% filter("C" %in% type) %>% 
            #filter(any(type == 'C')) %>% #as Ronak suggest
            #filter(length(unique(type))==4) %>% #OR using length and unique
            summarise(type_flow=paste(type, collapse="->"))

# A tibble: 2 x 2
   ID    type_flow      
  <fct> <chr>     
1 1     A->B->C->D
2 2     A->B->C->D

Answer 2

使用ave和aggregate(type~ID, mydata[ave(mydata$type == "C", mydata$ID, FUN = any), ], function(x) paste0(x, collapse = "->")) #ID type #1 1 A->B->C->D #2 2 A->B->C->D 的基本R选项

ave

逻辑与@A相同。在苏利曼的帖子中，我们将aggregate和type的变量ID和paste TimedeltaIndex过滤到数据框。

Answer 3

使用data.table：

setDT(mydata)
idsWC <- mydata[type == "C", unique(ID)]
mydata[ID %in% idsWC, paste(type, collapse = "->"), ID]
   ID         V1
1:  1 A->B->C->D
2:  2 A->B->C->D