Hi Thomas, Jeff is correct that this can be handled via merge, e.g. df3 <- merge( df2, df1, by="Serial", all=FALSE )
This operation is called an "inner join", and you could use other tools, such as the dplyr package to accomplish the same thing df3 <- dplyr::inner_join( df2, df1, by="Serial" ) HTH, Eric On Wed, Jan 8, 2020 at 5:05 PM Jeff Newmiller <[email protected]> wrote: > "merge" is generally the base R answer to this question, and there are > equivalent functions in various contributed packages. > > However, it is necessary to identify which columns in each table uniquely > identify each row ("primary key"). If your Serial 3036 shows up 10 times in > the first table and 10 times in the second table then you will end up with > all combinations of those rows (100 rows) in a merge that uses only Serial > to match rows. Is that what you want? > > > On January 8, 2020 6:52:18 AM PST, Thomas Subia <[email protected]> > wrote: > >Colleagues, > > > >I have two data frames which look like this. > > > >Data frame 1 > > > > Serial Pre.Hole Pre.flow Pre.Date > >1 3036 1 0.24 19-Nov-19 > >2 3036 2 0.212 19-Nov-19 > >3 3036 3 1.292 19-Nov-19 > >4 3036 4 0.262 19-Nov-19 > >5 3036 5 1.291 19-Nov-19 > >6 3036 6 0.26 19-Nov-19 > > > >Data frame 2 > > > > Serial Post.Hole Post.flow Post.Date > >62323 11024 44 -0.678 11-Dec-19 > >62324 11024 45 -0.659 11-Dec-19 > >62325 11024 46 -0.654 11-Dec-19 > >62326 11024 47 -0.699 11-Dec-19 > >62327 11024 48 -0.671 11-Dec-19 > >62328 11024 49 -0.687 11-Dec-19 > > > >What I want is to create a data frame whose serials numbers are common > >to data frames 1 and 2. > >The resulting data frame 1st row would look like this. > > > >Serial Post.Hole Post.flow Post.Date Pre.Hole > Pre.flow Pre.Date > > > >Any ideas on how to do this would be appreciated. > > > >Thomas Subia > >Statistician / Senior Quality Engineer > > > >IMG Companies > >225 Mountain Vista Parkway > >Livermore, CA 94551 > >T. (925) 273-1106 > >F. (925) 273-1111 > >E. [email protected] > > > > > >Precision Manufacturing for Emerging Technologies > >imgprecision.com > > > >The contents of this message, together with any attachments, are > >intended only for the use of the individual or entity to which they are > >addressed and may contain information that is legally privileged, > >confidential and exempt from disclosure. If you are not the intended > >recipient, you are hereby notified that any dissemination, > >distribution, or copying of this message, or any attachment, is > >strictly prohibited. If you have received this message in error, please > >notify the original sender or IMG Companies, LLC at Tel: 925-273-1100 > >immediately by telephone or by return E-mail and delete this message, > >along with any attachments, from your computer. Thank you. > > > >______________________________________________ > >[email protected] mailing list -- To UNSUBSCRIBE and more, see > >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. > > -- > Sent from my phone. Please excuse my brevity. > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see 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.
