[R] Comparing two variables for match and creating a new vector with results

[David Winsemius]

On Aug 25, 2012, at 7:12 PM, inti luna wrote:

> Hello,
>
> I need help comparing two variables and producing a third variable  
> with the
> result.I have this data:
>
> id <-c(1,2,3,4,5,6,7,8,9,10)
> vi <-c(1,0,1,1,1,1,1,2,2,0)
> vi2  <-c(0,1,1,1,1,1,1,2,0,0)
> data<-cbind(id,vi,vi2)
>
> For the data in the example, I need to generate:
> id <-c(1,2,3,4,5,6,7,8,9,10)
> correct <-c(0,0,1,1,1,1,1,1,0,1)
> correct_data<-cbind(id,correct)

correct <- (vi == vi2)  # although parens are superfluous

The cbind() operation  coerces the logical vector to numeric.

>
> Matrix "correct_data"is the result of comparing "vi" with "vi2" and  
> see if
> they match. If the values are the same correct value=1 and if not  
> correct
> value=0 keeping the same id position.
>
> How can I do this? I tried with match and with %in% but is not  
> exactly what
> I need.
>
> Thanks in advance!
>
> Inti Luna
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.

David Winsemius, MD
Alameda, CA, USA