I've attached some functions I've written based on previous questions that have been posted here. Unfortunately, I was too lazy to give credit to previous commenters in my Rd file, and for that I hope they'll forgive me.
In any case, please be assured that the functions I've attached are in no way my original work. Benjamin -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of wookie1976 Sent: Tuesday, February 23, 2010 12:40 PM To: r-help@r-project.org Subject: [R] First. Last. Data row selection I am in the process of switching from SAS over to R. I am working on very large CSV datasets that contain vehicle information. As I am processing the data, I need to select the first (or sometimes the second) record (by date) for any records that have the same license plate number. In SAS, there is a function called 'first.' that can be used on sorted datasets to pull out those first entries for each occurrence of a particular variable (in this case the variable is 'license plate') found in the data. I have spent some time looking around and cannot seem to find an equivalent function in R. Can anyone recommend an efficient technique that would pull this off? I assume the database must first be sorted by vehicle plate and date, and then apply the filter or function. Any help would be greatly appreciated. Thanks, Joe -- View this message in context: http://n4.nabble.com/First-Last-Data-row-selection-tp1566260p1566260.htm l 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. =================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S.News & World Report (2009). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you.
______________________________________________ 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.
