How to remove row if it has a NA value in one certain column

Question

My data called "dat":

I want to be all rows to be removed if it has an NA in column B:

na.omit(dat) removes all rows with an NA not just the ones where the NA is in column B.

Also I'd like to know how to this for NA value in two columns.

I appreciate all advice!

Try with `is.na` i.e. `dat[!is.na(dat$B),]` or `subset(dat, !is.na(B))` or `library(dplyr);dat %>% filter(!is.na(B))` or `data.table` `setDT(dat)[!is.na(B)]` — akrun, Feb 07 '18 at 08:14

score 58 · Accepted Answer · answered Feb 07 '18 at 08:29

58

The easiest solution is to use is.na():

df[!is.na(df$B), ]

which gives you:

answered Feb 07 '18 at 08:29

clemens

Why do you need the comma "," after "(df$B)" ? – Emil Krabbe Mar 11 '21 at 13:45
6

when you subset a data.frame with square brackets, the element before the comma applies to rows, the element after the comma to columns. if you don't use the comma, R will assume you are selecting columns. – clemens Mar 11 '21 at 15:46
1

This answer provides a big speed improvement over the tidyverse option! Average speed of 200us (base) vs 1400ms (tidyverse) – JJ Fantini Aug 31 '22 at 16:34

score 25 · Answer 2 · edited May 07 '20 at 04:48

25

there is an elegant solution if you use the tidyverse!

it contains the library tidyr that provides the method drop_na which is very intuitive to read.

So you just do:

library(tidyverse)

dat %>% drop_na("B")

OR

dat %>% drop_na(B)

if B is a column name

edited May 07 '20 at 04:48

Jake

answered May 17 '19 at 09:48

Agile Bean

I'd add that this answer is useful if passing strings to functions which are intended to be used as column names. – Bradford Aug 04 '22 at 16:43

score 6 · Answer 3 · answered Feb 07 '18 at 08:16

6

try this:

df<-data.frame(A=c(NA,1,1,1),B=c(2,2,NA,2),C=c(NA,3,3,3))
df<-df[-which(is.na(df$B)),]
df
   A B  C
1 NA 2 NA
2  1 2  3
4  1 2  3

answered Feb 07 '18 at 08:16

jyjek

score -1 · Answer 4 · edited Feb 17 '22 at 07:02

-1

This should work

dat <- dat[dat['B'].notnull()]

edited Feb 17 '22 at 07:02

ah bon

answered Jun 03 '19 at 04:51

Shraddha Kulal

4 Answers4