Re: [R] Unique?

From: Francisco J. Zagmutt <gerifalte28_at_hotmail.com>
Date: Thu 11 May 2006 - 08:05:43 EST


If you only care about the sum of CONVUNIT by each TRIPID then you can use tapply i.e.:

step4<-data.frame(TRIPID=rep(c(111,222,333),3),CONVUNIT=rpois(9,40)) result<-tapply(step4$CONVUNIT,INDEX=step4$TRIPID,FUN=sum) result
111 222 333
115 107 123

Is this what you wanted to do? I can't think of anything faster than tapply for your problem.

I hope this helps

Francisco

>From: "Guenther, Cameron" <Cameron.Guenther@MyFWC.com>
>To: <r-help@stat.math.ethz.ch>
>Subject: [R] Unique?
>Date: Wed, 10 May 2006 17:02:33 -0400
>
>
>Hello,
>I have sample data set that looks like:
>
>YEAR MONTH DAY CONTINUE SPL TIMEFISH
>TIMEUNIT AREA COUNTY DEPTH DEPUNIT GEAR TRIPID
>CONVUNIT
>1992 1 26 1 SP0073928 8
>H 7 25 4 NA 1000000
>02163399054 161
>1992 1 26 1 SP0073928 8
>H 7 25 4 NA 1000000
>02163399054 8
>1992 1 26 2 SP0004228 8
>H 7 25 4 NA 1000000
>02163399054 161
>1992 1 26 2 SP0004228 8
>H 7 25 4 NA 1000000
>02163399054 8
>1992 1 25 NA SP0052652 8
>H 7 25 4 NA 1000000
>02163399057 85
>1992 1 26 NA SP0037940 8
>H 7 25 4 NA 1000000
>02163399058 70
>1992 1 27 NA SP0072357 8
>H 7 25 4 NA 1000000
>02163399059 15
>1992 1 27 NA SP0072357 8
>H 7 25 4 NA 1000000
>02163399059 20
>1992 1 27 NA SP0026324 8
>H 7 25 4 NA 1000000
>02163399060 8
>1992 1 28 1 SP0072357 8
>H 7 25 4 NA 1000000
>02163399062 200
>
>How can I use unique to extract the rows that have repeated tripid's
>only, not a unique value for each variable but only for TRIPID. I then
>want to condense the unique values by summing the CONVUNIT for each
>unique value of TRIPID. I posted a similar question last week and
>received a sufficient answer of how to do this without using uniqe. The
>solution below worked just fine on this sample data set but the full
>data set has 446,000 rows of data and my computer and R simply cannot
>handle this follwing code on data this large.
>
>conds<-by(Step4,Step4$TRIPID,function(x)
>replace(x[1,],"CONVUNIT",sum(x$CONVUNIT)))
>Step5<-do.call(rbind,conds)
>
>Thank you,
>
>Cameron Guenther, Ph.D.
>Associate Research Scientist
>FWC/FWRI, Marine Fisheries Research
>100 8th Avenue S.E.
>St. Petersburg, FL 33701
>(727)896-8626 Ext. 4305
>cameron.guenther@myfwc.com
>
>______________________________________________
>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 Thu May 11 08:15:34 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Thu 11 May 2006 - 10:10:08 EST.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.