How do I delete row with condition on NA

Question

First, how do I change NA into anything?

x[x==NA] <- "anything"

This does not work.

Also, how do I delete a row in a dataframe with condition on NA? For example:

    [,1][,2][,3]
[1,]  NA  NA 284
[2,] 233 182 249
[3,] 177 201  NA

I want to delete the row which has 2 or more NA in that particular row, so it will result in:

    [,1][,2][,3]
[2,] 233 182 249
[3,] 177 201  NA

Someone marked my question duplicated, but actually I want to control the amount of NA to delete a row, complete.cases(x) cannot provide any control to it.

I appreciate that you might have been unclear in your own mind as to what you wanted, but it's a little bit cheesy to change your question after it's been answered. I've added a solution to your (updated) problem to @RHertel's answer ... — Ben Bolker, Jan 28 '16 at 22:44
PS http://thomasleeper.com/Rcourse/Tutorials/NAhandling.html — Ben Bolker, Jan 28 '16 at 22:52

HubertL · Answer 1 · 2016-01-28T22:41:03.523

2

You can also use complete.cases():

x <- x[complete.cases(x),]

edited Jan 28 '16 at 22:41

answered Jan 28 '16 at 21:51

HubertL

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Thanks for noticing the mistake @RHertel – HubertL Jan 28 '16 at 22:41

score 1 · Answer 2 · edited Jan 28 '16 at 22:43

1

Here's another possibility:

x[!is.na(rowSums(x)),]
#[1] 233 182 249

data

x <- matrix(c(NA , NA, 284, 233, 182, 249, 177, 201, NA), byrow=TRUE, ncol=3)

To control the tolerance for NA values (e.g. exclude only rows with at least 2 NA values):

x[rowSums(is.na(x))<2,]

edited Jan 28 '16 at 22:43

Ben Bolker

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answered Jan 28 '16 at 21:54

RHertel

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Thank you for the improvement / adaptation, @BenBolker – RHertel Jan 29 '16 at 06:40

score 0 · Answer 3 · answered Jan 28 '16 at 22:58

0

To replace NAs:

x[which(is.na(x))] <- 0  # will be replaced by 0

To remove rows with two or more NA using apply function:

x[-which(apply(x, 1, function(xx) length(which(is.na(xx)))) >= 2),]

answered Jan 28 '16 at 22:58

Pandya21

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score 0 · Answer 4 · answered Jan 28 '16 at 23:01

I think the others answer the 2nd part of your question. To answer your first part.

If x is a vector

x <- c(1,2,3,NA,4,NA)
x[is.na(x)] <- "anything"

If x is a data frame

x <- c(1,1,1,NA,1,NA)
df <- data.frame(var1=x,var2=x)
df$var1[is.na(df$var1)] <- -1

How do I delete row with condition on NA

4 Answers4