Hi without real data I can suggest you to look to ?merge. Or maybe ?aggregate.
Regards Petr > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Adeel Amin > Sent: Thursday, May 02, 2013 8:28 AM > To: r-help@r-project.org > Subject: [R] R issue with unequal large data frames with multiple > columns > > I'm a bit of an amateur R programmer. I can do simple R scenarios but > my handle on complex grammatical issues isn't steady. > > I have 12 CSV files that I've read into dataframes. Each has 8 columns > and over 2000000 rows. Each dataframe has data associated by time > component and a date component in the format of: > > X.DATE and then X.TIME > > X.DATE is in the format of MMDDYYYY and X.TIME is format HHMM. The > issue is that even though each dataframe begins and ends with the same > X.DATE and X.TIME values, each data frame has different number of rows. > One may have as many 100000 rows more than the other. > > I want to do two things: > > 1) I want to extract a certain portion of data depending on date and > time > (easy) > > 2) In lock step with number 2 I want to eliminate values from the data > frame that are a) redundant or b) do not appear in the other data sets. > > When step 2 is done, all the time/date data within all 12 dataframes > will be the same. > > Suggestions? Thanks R Community -- > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.
