问题
I'm a pretty beginner at R. I've a CSV file where data is as follows, for example:
ID Values
820 D1,D2,FE
730 D1,D2,D3,PC,Io,He,Bt,Te,AR,PG
730 DV,GTH,LYT
567 EDR,TYU,EOP,OMN
567 FGH,KIH,IOP
I want to remove the duplicates in ID and append their data into its Values column, like this:
ID Values
820 D1,D2,FE
730 D1,D2,D3,PC,Io,He,Bt,Te,AR,PG,DV,GTH,LYT
567 EDR,TYU,EOP,OMN,FGH,KIH,IOP
How to achieve this in R?
回答1:
dat <- read.table(text="ID Values
820 D1,D2,FE
730 D1,D2,D3,PC,Io,He,Bt,Te,AR,PG
730 DV,GTH,LYT
567 EDR,TYU,EOP,OMN
567 FGH,KIH,IOP", header=TRUE)
dat2 <- dat %>% group_by(ID) %>% summarise(val=paste(Values, collapse=","))
回答2:
You can try
library(data.table)
setDT(df1)[, list(Values=paste(Values, collapse=",")) ,ID]
Or using base R
aggregate(.~ID, df1, paste, collapse=",")
来源：https://stackoverflow.com/questions/30235606/how-to-combine-rows-based-on-unique-values-in-r