On 10/02/2008, joseph <[EMAIL PROTECTED]> wrote:
> Hello
> I have 2 data frames df1 and df2. I would like to create a
> new data frame new_df which will contain only the common rows based on the
> first 2
> columns (chrN and start). The column score in the new data frame
> should
> be replaced with a column containing the average score (average_score) from
> df1
> and df2.
Try this: (avoiding underscores)
new.df <- merge(df1, df2, by=c('chrN','start'))
new.df$average.score <- apply(df3[,c('score.x','score.y')], 1, mean, na.rm=T)
As always, interested to see whether it can be done in one line...
--
Dr. Mark Wardle
Specialist registrar, Neurology
Cardiff, UK
______________________________________________
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.
