thanks, Andy and John, for suggestions. worked great. jeff
****************************************** Jeffrey Moore, Ph.D. Postdoctoral Research Scientist Duke Center for Marine Conservation Duke University Marine Laboratory 135 Duke Marine Lab Road Beaufort, NC 28516 Phone: (252) 504-7653 Fax: (252) 504-7689 Email: [EMAIL PROTECTED] ***************************************** -----Original Message----- From: John Fox [mailto:[EMAIL PROTECTED] Sent: Friday, February 10, 2006 10:13 PM To: 'Jeffrey Moore' Cc: [EMAIL PROTECTED]; [email protected] Subject: RE: [R] how do I "relate" tables in R? Dear Jeff, Assuming that the column named "z" in the matrix data2 already exists and has arbitrary content (such as 0's or NA's), how about the following? data2[,"z"] <- data1[data2[,"ID"], "z"] I hope this helps, John -------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario Canada L8S 4M4 905-525-9140x23604 http://socserv.mcmaster.ca/jfox -------------------------------- > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jeffrey Moore > Sent: Friday, February 10, 2006 9:23 PM > To: [email protected] > Cc: [EMAIL PROTECTED] > Subject: [R] how do I "relate" tables in R? > > Hi all, > > I'm new to the list...pretty new at learning to code in R... > > Is there a way to relate 2 different arrays in R? > > Hypothetical example: > > data1 > ID z > 1 100 > 2 250 > 3 75 > 4 12 > 5 89 > > data2 > ID z > 1 > 1 > 1 > 1 > 2 > 3 > 4 > 3 > 4 > 5 > 5 > 5 > etc. > > Goal is to fill column z in data2 with appropriate z-values from data1 > that correspond to a given ID. > > I'm looking for something akin to a relational database, or a lookup > table in Excel. > > I can construct a simple for-loop (with if else statement) to fill the > z-column in data2, but in my case data2 is 150,000 records long, so > this approach is not efficient. > > Thanks for any help > Jeff > > ****************************************** > Jeffrey Moore, Ph.D. > Postdoctoral Research Scientist > Duke Center for Marine Conservation > Duke University Marine Laboratory > 135 Duke Marine Lab Road > Beaufort, NC 28516 > Phone: (252) 504-7653 > Fax: (252) 504-7689 > Email: [EMAIL PROTECTED] > ***************************************** > > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
