Exactly what results are you expecting?  Your 'match' has the same variables
in both locations and will therefore return the first match:

> match(TazProperties..$Props,TazProperties..$Props)
 [1] 1 1 1 4 4 4 4 8 8 8 8 8
so you are getting the results that you ask for.

On Mon, Feb 22, 2010 at 5:42 PM, LCOG1 <jroll@lcog.org> wrote:

>
>
> Howdy y'all,
>
> I am looking to use the match function to match a data attribute to another
> data frame but i need it to do so on two criteria to ensure an appropriate
> match.  The following matches incorrectly.  I know the example looks
> pointless but its just an example.  Perhaps there is another way of doing
> this?  Thanks
>
> #Sample Data
> Props<-c("p754921","p754921" ,"p754921","p75506" ,"p75506"
>  ,"p75506","p75506"
>  ,"p75508","p75508","p75508","p75508","p75508")
>  TAZ<-c(38,37,37,171,171,282,171,46,46,169,169,169)
>  Area<-c(109828.04,  128134.71,   46469.57, 37160.21,
>  40080.50,344679.66,16972.28,
>  342309.558, 260906.870,  17014.659,   7285.706,  10936.316)
> #Creat 1st dataframe
> TazProperties..<-data.frame(Props,TAZ,Area)
>  #Sample Data
> Props2<-c("p754921","p754921","p754921","p75506" ,"p75506"
>  ,"p75506","p75506" ,"p75508","p75508","p75508","p75508","p75508")
>  TAZ2<-c(38,37,37,171,171,282,171,46,46,169,169,169)
> #Create 2nd data frame
> TazProperties2..<-data.frame(Props2,TAZ2)
>
> #match on prop and return area to data frame
>
> TazProperties2..$Area<-TazProperties..$Area[match(TazProperties..$Props,TazProperties..$Props)]
>
> --
> View this message in context:
> http://n4.nabble.com/matching-on-two-criteria-tp1565265p1565265.html
> 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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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