It dopes appear that this code works but entering a NA into the TAZ values goofs things up. Any ideas of how to remedy this problem?
-----Original Message----- From: Nikhil Kaza [mailto:nikhil.l...@gmail.com] Sent: Monday, February 08, 2010 4:51 PM To: ROLL Josh F Cc: r-help@r-project.org Subject: Re: [R] Selecting single TAZ based on area proportion try this t <- TazProperties.. v <- aggregate(t$Area, by=list(t$TAZ,t$Props), sum) names(v) <- c("TAZ", "Prop", "area") tapply(v$area, v$Prop, function(x) v$TAZ[which.max(x)]) note that you have to deal with the cases where there is a tie for the maximum. The above just returns the first maximum. Nikhil On Feb 8, 2010, at 1:14 PM, LCOG1 wrote: > > Good day all, > I am having an issue coercing my data. Below i have some data on > taxlots and an associated TAZ(transportation analsysi zone) that each > property is within. The main issue is that some properties cross TAZ > boundaries so i need to make a decision as to which TAZ the property > belongs too, i would like to do this based on the area of the Property > and ultimately assign the the property to the TAZ in which the > majority or the most of the area is within. For instance in the data > below: > > Property p754921 is in two TAZs, 38 and 37. Since the property is > mostly in 37 i would like to assign this value to the list of > properties(Props) so > that > > MultiTazProperties_ goes from > > $p754921 > [1] 38 37 37 > > $p75506 > [1] 171 171 282 171 > > $p75508 > [1] 46 46 169 169 169 > > to.... > > $p754921 > [1] 37 > > $p75506 > [1] 282 > > $p75508 > [1] 46 > > Props TAZ Area > 1 p754921 38 109828.040 > 2 p754921 37 128134.710 > 3 p754921 37 46469.570 > 4 p75506 171 37160.210 > 5 p75506 171 40080.500 > 6 p75506 282 344679.660 > 7 p75506 171 16972.280 > 8 p75508 46 342309.558 > 9 p75508 46 260906.870 > 10 p75508 169 17014.659 > 11 p75508 169 7285.706 > 12 p75508 169 10936.316 >> > > > #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) > > MultiTazProperties_<-tapply(TAZ , Props, function(x) x) > MultiTazArea_<-tapply(Area , Props, function(x) x) > > Hope my inquiry is clear. Thanks > -- > View this message in context: > http://n4.nabble.com/Selecting-single-TAZ-based-on-area-proportion-tp1 > 473288p1473288.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 > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ 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.
