CODEWITHSUNDEEP
rdataframe
C78
C78

Reputation: 21

Paste values together based on a grouping variable

I'm new at R programing and Im trying to rearrange a data frame. Basically I have a column with IDs and a column with y string values. There's more than one y per ID so multiple rows with the same ID but different y. I want to get only one row per ID and all the y value concatenated in the same cell in the other column. Is there a function that does that ? 

original data

ID  y
A   apple
B   pear
C   grape
A   grape
B   apple
C   grape

transformed data  

ID   y  
A    apple,grape  
B    pear, apple  
C    grape

Upvotes: 2

Views: 2031

Answers (1)

user20650
user20650

Reputation: 25854

You can use aggregate() here to paste() the unique() elements for each IDtogether

aggregate(y ~ ID, unique(dat), paste, collapse = ", ")

data

dat <- read.table(text="ID  y
A   apple
B   pear
C   grape
A   grape
B   apple
C   grape", header=T)

EDIT added collapse argument re @pdb comment and changed unique re @DavidArenburg

Upvotes: 5

Related Questions