From: John Fox <jfox_at_mcmaster.ca>

Date: Sat 11 Feb 2006 - 14:13:18 EST

John Fox

Department of Sociology

McMaster University

Hamilton, Ontario

Canada L8S 4M4

905-525-9140x23604

http://socserv.mcmaster.ca/jfox

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Feb 11 14:17:17 2006

Date: Sat 11 Feb 2006 - 14:13:18 EST

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: r-help-bounces@stat.math.ethz.ch

*> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of Jeffrey Moore
**> Sent: Friday, February 10, 2006 9:23 PM
**> To: r-help@stat.math.ethz.ch
**> Cc: colchero@duke.edu
**> 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: jemoore@duke.edu
**> *****************************************
**>
**>
**> [[alternative HTML version deleted]]
**>
**> ______________________________________________
**> R-help@stat.math.ethz.ch mailing list
**> https://stat.ethz.ch/mailman/listinfo/r-help
**> PLEASE do read the posting guide!
**> http://www.R-project.org/posting-guide.html
*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Feb 11 14:17:17 2006

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