HI,
I tried two ways in aggregate. The results are the same.
dat1<-read.table(text="
Data Plot Lat LatCat Elevation ElevCat Type SizeClass
Stems Area Density
VTM 39C16 39.76282 Lat6 1500 Elev1 Conifer Class3 0
751.5347 0.00000
VTM 39C16 39.76282 Lat6 1500 Elev1 Conifer Class4 1
751.5347 13.30611
VTM 39F11 39.57721 Lat6 500 Elev1 Conifer Class3 0
751.5347 0.00000
VTM 39F11 39.57721 Lat6 500 Elev1 Conifer Class4 0
751.5347 0.00000
VTM 39F13 39.56214 Lat6 1500 Elev1 Conifer Class3 3
694.0784 0.00000
VTM 39F13 39.56214 Lat6 1500 Elev1 Conifer Class4 1
694.0784 0.00000
VTM 39F14 39.54522 Lat6 900 Elev1 Conifer Class3 1
763.9850 13.08926
VTM 39F14 39.54522 Lat6 900 Elev1 Conifer Class4 2
763.9850 0.00000
",sep="",header=TRUE, stringsAsFactors=FALSE)
> with(dat1,aggregate(Stems,list(Plot,Data,Lat,LatCat,Elevation,Type,Area,Density),sum))
Group.1 Group.2 Group.3 Group.4 Group.5 Group.6 Group.7 Group.8 x
1 39F13 VTM 39.56214 Lat6 1500 Conifer 694.0784 0.00000 4
2 39F11 VTM 39.57721 Lat6 500 Conifer 751.5347 0.00000 0
3 39C16 VTM 39.76282 Lat6 1500 Conifer 751.5347 0.00000 0
4 39F14 VTM 39.54522 Lat6 900 Conifer 763.9850 0.00000 2
5 39F14 VTM 39.54522 Lat6 900 Conifer 763.9850 13.08926 1
6 39C16 VTM 39.76282 Lat6 1500 Conifer 751.5347 13.30611 1
> aggregate(Stems~Plot+Data+Lat+LatCat+Elevation+Type+Area+Density,data=dat1,sum)
Plot Data Lat LatCat Elevation Type Area Density Stems
1 39F13 VTM 39.56214 Lat6 1500 Conifer 694.0784 0.00000 4
2 39F11 VTM 39.57721 Lat6 500 Conifer 751.5347 0.00000 0
3 39C16 VTM 39.76282 Lat6 1500 Conifer 751.5347 0.00000 0
4 39F14 VTM 39.54522 Lat6 900 Conifer 763.9850 0.00000 2
5 39F14 VTM 39.54522 Lat6 900 Conifer 763.9850 13.08926 1
6 39C16 VTM 39.76282 Lat6 1500 Conifer 751.5347 13.30611 1
The rows with 39.57721 and 39.56214 are the same for SizeClass except the Stems
#. It got summed. Otherwise, it is giving both Class3 and Class4 values
separately.
A.K.
----- Original Message -----
From: Christopher R. Dolanc <crdol...@ucdavis.edu>
To: arun <smartpink...@yahoo.com>
Cc:
Sent: Tuesday, August 7, 2012 6:38 PM
Subject: Re: [R] summing and combining rows
Hmmm. It looks like it's only giving me the values for Class3, instead
of summing, which is why I thought the "+" method might not be the
appropriate coding.
Here's the code I used:
> CH_Con_Elev1SC34a<-
aggregate(Stems~Plot+Data+Lat+LatCat+Elevation+Type+Area+Density,
data=CH_Con_Elev1SC34, sum)
> CH_Con_Elev1SC34b<- data.frame(CH_Con_Elev1SC34a,
SizeClass=rep("Class34",))
If it helps, attached is a txt file with the data structure.
On 8/7/2012 3:00 PM, arun wrote:
>
> Hi,
> Not sure why you mentioned "+" doesn't work.
> dat1<-read.table(text="
> Plot Elevation Area SizeClass Stems
> 12 1200 132.4 Class3 0
> 12 1200 132.4 Class4 1
> 17 2320 209.1 Class3 3
> 17 2320 209.1 Class4 5
> ",sep="",header=TRUE,stringsAsFactors=FALSE)
>
> dat2<-aggregate(Stems~Plot+Elevation+Area, data=dat1,sum)
> dat3<-data.frame(dat2,SizeClass=rep("Class34",2))
> dat3<-dat3[,c(1:3,5,4)]
> dat3
> # Plot Elevation Area SizeClass Stems
> #1 12 1200 132.4 Class34 1
> #2 17 2320 209.1 Class34 8
>
> A.K.
>
>
>
>
>
>
> ----- Original Message -----
> From: Christopher R. Dolanc <crdol...@ucdavis.edu>
> To: arun <smartpink...@yahoo.com>
> Cc:
> Sent: Tuesday, August 7, 2012 5:47 PM
> Subject: Re: [R] summing and combining rows
>
> Thanks for your response. The aggregate method mostly works for me, but
> I have numerous other columns that I'd like to keep in the result. So,
> if I have something like this:
>
>
> Plot Elevation Area SizeClass Stems
> 12 1200 132.4 Class3 0
> 12 1200 132.4 Class4 1
> 17 2320 209.1 Class3 3
> 17 2320 209.1 Class4 5
>
> How can I make it look like this?
>
> Plot Elevation Area SizeClass Stems
> 12 1200 132.4 Class34 1
> 17 2320 209.1 Class34 8
>
> I see something in ?aggregate about adding columns with a +, but this
> doesn't quite work for me.
>
>
> On 8/7/2012 2:32 PM, arun wrote:
>> Hi,
>>
>> Try this:
>> dat1<-read.table(text="
>> Plot SizeClass Stems
>> 12 Class3 1
>> 12 Class4 3
>> 17 Class3 5
>> 17 Class4 2
>> ",sep="",header=TRUE, stringsAsFactors=FALSE)
>>
>>
>>
>> ddply(dat1,.(Plot), summarize, sum(Stems))
>>
>> #or
>>
>>
>> dat2<-aggregate(Stems~Plot,data=dat1,sum)
>> dat3<-data.frame(dat2,SizeClass=rep("Class34",2))
>> dat3
>> # Plot Stems SizeClass
>> #1 12 4 Class34
>> #2 17 7 Class34
>>
>>
>> A.K.
>>
>> ----- Original Message -----
>> From: Christopher R. Dolanc <crdol...@ucdavis.edu>
>> To: r-help@r-project.org
>> Cc:
>> Sent: Tuesday, August 7, 2012 1:47 PM
>> Subject: [R] summing and combining rows
>>
>> Hello,
>>
>> I have a data set that needs to be combined so that rows are summed by a
>> group based on a certain variable. I'm pretty sure rowsum() or rowsums() can
>> do this but it's difficult for me to figure out how it will work for my data
>> based on the examples I've read.
>>
>> My data are structured like this:
>>
>> Plot SizeClass Stems
>> 12 Class3 1
>> 12 Class4 3
>> 17 Class3 5
>> 17 Class4 2
>>
>> I simply want to sum the size classes by plot and create a new data frame
>> with a size class called "Class34" or with the SizeClass variable removed. I
>> actually do have other size classes that I want to leave alone, but combine
>> 3 and 4, so if I could figure out how to do this by creating a new class,
>> that would be preferable.
>>
>> I've also attached a more detailed sample of data.
>>
>> Thanks,
>> Chris Dolanc
>>
>> -- Christopher R. Dolanc
>> Post-doctoral Researcher
>> University of Montana and UC-Davis
>>
>>
>> ______________________________________________
>> 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.
>>
>>
--
Christopher R. Dolanc
Post-doctoral Researcher
University of Montana and UC-Davis
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