Unexpected output in converting numeric variable to a dummy variable in data frame - R

Question

I have this numerical variable in a data frame in R:

> head(sdbone$ncorrectas)
[1] 29 14 21 12 17  6

Then, I try to convert it to a dummy variable based on the condition that if ncorrectas > 10 it should have the value 1, otherwise 0:

I tried the following code :

> sdbone$ncorrectas < - ifelse(sdbone$ncorrectas > 10,1,0)

However, the variable doesn't change at all. So what's wrong with my code? and How Can I convert it to a dummy variable as I want to ?

This question appears to be off-topic because it is about a typo — Ricardo Saporta, Sep 28 '14 at 19:13
I didn't know how necessary is avoid space between < and - . I thought it was the same as <- . That was the problem. — CreamStat, Sep 28 '14 at 19:17

score 1 · Accepted Answer · answered Sep 28 '14 at 19:13

1

remove the space between < and - ;)

Also, instead of ifelse, use the following

 sdbone$ncorrectas <- as.numeric(sdbone$ncorrectas > 10)

answered Sep 28 '14 at 19:13

Ricardo Saporta

I didn't know how necessary is avoid space between < and - . Thnaks! – CreamStat Sep 28 '14 at 19:18
no prob. We all learned the same thing at one point or another :) – Ricardo Saporta Sep 28 '14 at 21:25

1 Answers1