As df2 has only one column and is thus effectively a variable in this case, you don't even need to merge.
df1[df1$gene_name%in%df2$gene_name , ] should do. HTH, Daniel wong, honkit (Stephen) wrote > > Dear Experienced R users, > > I have a looks-like simple but complicated problem urgently needed to be > solved. Below is the detail: > > I have two dataframes, df1, df2. df1 contains two column and many > thousands rows: column 1 is a "gene_name", column 2 is "value". df2 > contains only one column which is "gene_name" with couple hundred rows. I > want to change "value" of df2 for those "gene_name" also appear in df2 > "gene_name". How to do that? Millions thanks. > > > Ste > > ______________________________________________ > R-help@ 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. > -- View this message in context: http://r.789695.n4.nabble.com/a-newbie-seeking-for-a-simple-problem-tp4642029p4642031.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
