CODEWITHSUNDEEP
rif-statement
user3021648
user3021648

Reputation: 67

If Statement - Condition Length Greater Than 1

I have two columns (df$Z and df$A)

I basically want to say: if df$Z is less than 5, then fill df$A with an NA and if not then leave df$A alone. I've tried these things but am not sure where I'm going wrong or what the error message means.

if(df$X<5){df$A <- NA}

Error:

In if (df$X < 5) { : the condition has length > 1 and only the first element will be used

I also tried to do something more like this.

for(i in dfX){
if(df$X<5){
df$A <- "NA"
 }
}

Upvotes: 1

Views: 22413

Answers (3)

Beasterfield
Beasterfield

Reputation: 7113

The vectorized form of the if statement in R is the ifelse() function:

df$A <- ifelse( df$X < 5, NA, df$A )

However, in this case I would also go with @mark-heckmann's solution.

And please note, that "NA"is not the same as NA.

Upvotes: 1

Sven Hohenstein
Sven Hohenstein

Reputation: 81683

A simple way is the "is.na<-" function:

is.na(df$A) <- df$Z < 5

Upvotes: 1

Mark Heckmann
Mark Heckmann

Reputation: 11431

No if statement needed. That's the magic of vectorization. 

df$A[df$Z < 5] <- NA

Upvotes: 6

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