CODEWITHSUNDEEP
rdplyr
daj
daj

Reputation: 7183

R / dplyr : How to use filter functions in conjunction with the pipelining %>% operator?

I'm sure there's an idiom for doing this, but how exactly do I pipeline a boolean mask or row selection to a filter operation using dplyr.

For example, here I want to select out rows of foo for which id is duplicated:

foo$id %>% duplicated %>% filter(foo ??)

I can do this with an anonymous function, but there must be a better way than:

foo$id %>% duplicated %>% function(x) foo[x,]

Upvotes: 1

Views: 888

Answers (1)

MrFlick
MrFlick

Reputation: 206197

The problem is that you are trying to send vector down the pipe when dplyr is really meant to be used with table-like objects so you should be sending the whole data.frame (assuming that's what foo is. For example

library(dplyr)
foo <- data.frame(id=sample(1:5, 25, replace=T), val=runif(25))
foo %>% filter(!duplicated(id))

If you really only want the ID's, then add

foo %>% filter(!duplicated(id)) %>% select(id)

Upvotes: 3

Related Questions