Hello,
Inline.
Em 11-09-2012 15:57, Simon Kiss escreveu:
Hi:
I have two variables in a data frame that are the results of a wording
experiment in a survey. I'd like to create a third variable that combines the
two variables. Recode doesn't seem to work, because it just recodes the first
variable into the third, then recodes the second variable into the third,
overwriting the first recode. I can do this with a rather elaborate indexing
process, subsetting the first column and then copying the data into the second
etc. But I'm looking for a cleaner way to do this. The data frame looks like
this.
df<-data.frame(var1=sample(c('a','b','c',NA),replace=TRUE, size=100),
var2=sample(c('a','b','c',NA),replace=TRUE,size=100))
df<-subset(df, !is.na(var1) |!is.na(var2))
As you can see, if one variable has an NA, then the other variable has a valid
value,
No, not necessarily. You are using sample() and there's no reason to
believe the sampled values for var1 and var2 are going to be different.
My first try gave me several rows with both columns NA. Then I've used
set.seed() and it became reproducible.
set.seed(1)
df1 <- data.frame(var1=sample(c('a','b','c',NA), replace=TRUE, size=100),
var2=sample(c('a','b','c',NA), replace=TRUE, size=100))
sum(is.na(df1$var1) & is.na(df1$var2)) # 8
So I suppose this is not the case with your real dataset.
Try the following.
df1$var3 <- df1$var1
df1$var3[is.na(df1$var1)] <- df1$var2[is.na(df1$var1)]
Hope this helps,
Rui Barradas
so how do I just combine the two variables into one?
Thank you for your assistance.
Simon Kiss
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
