Jim Moon <moonja <at> ohsu.edu> writes:
> How might one accomplish this using the by() function?
> m1 is a data frame.
>
> # populate column "m1$major_allele"
> for ( i in 1:length(m1$major_allele)) {
> if ( m1$Freq1[i] == m1$MAF[i]){
> m1$major_allele[i] = m1$Al1[i]
> }
> else{
> m1$major_allele[i] = m1$Al2[i]
> }
> }
You could use:
m1$major_allele <- ifelse( m1$Freq1 == m1$MAF, m1$Al1, m1$Al2 )
Greg
______________________________________________
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.
