Is this better:
> sapply(split(v, v$Prop), function(x) x$TAZ[which.max(x$area)])
p754921 p75506 p75508
37 282 46
>
Take a look at what you were doing. The result of the 'tapply' is to
split v$area in to smaller groups based on v$Prop, so the 'x'
parameter is not going to be the same length as your 'v' dataframe and
therefore you are indexing to the incorrect value. Best to split the
dataframe and then operate on the individual portions.
On Tue, Feb 23, 2010 at 3:47 PM, LCOG1 <[email protected]> wrote:
>
> Please consider the following
>
> #Data to use
> Props<-c("p754921","p754921" ,"p754921","p75506" ,"p75506"
> ,"p75506","p75506","p75508","p75508","p75508","p75508","p75508")
> TAZ<-c(38,37,37,171,171,282,171,46,46,169,169,169)
> Area<-c(109828.04, 128134.71, 46469.57, 37160.21,
> 40080.50,344679.66,16972.28,
> 342309.558, 260906.870, 17014.659, 7285.706, 10936.316)
>
> TazProperties..<-data.frame(Props,TAZ,Area)
>
>
> t <- TazProperties..
> v <- aggregate(t$Area, by=list(t$TAZ,t$Props), sum)
> names(v) <- c("TAZ", "Prop", "area")
> a<-tapply(v$area, v$Prop, function(x) v$TAZ[which.max(x)])
>
> "a" returns:
>
> p754921 p75506 p75508
> 37 38 37
>
> and it should return
>
> p754921 p75506 p75508
> 37 282 46
>
> What am i doing wrong? Thanks
> --
> View this message in context:
> http://n4.nabble.com/select-row-based-on-highest-value-tp1566510p1566510.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [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
> 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?
______________________________________________
[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
and provide commented, minimal, self-contained, reproducible code.
