Re: [R] optimal way to compute matrix subtotals?

From: Werner Wernersen <pensterfuzzer_at_yahoo.de>
Date: Mon 15 May 2006 - 02:04:21 EST


Thank you all for your replys!

It is so much faster with rowsum(), thanks a million!   Werner

Dimitris Rizopoulos <dimitris.rizopoulos@med.kuleuven.be> schrieb: probably you want ?rowsum(); I hope it helps.

Best,
Dimitris



Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium

Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://www.med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


To:
Sent: Friday, May 12, 2006 11:48 AM
Subject: [R] optimal way to compute matrix subtotals?

> Hi!
>
> I have large matrices, one column per variable and I have a vector
> of factors / grouping symbols. Then I am computing subtotals for the
> groups but it takes pretty long and thus I wanted to ask if there is
> a better way to do it or if this is already the best way:
> subTotals <- function(x, groupvec)
> do.call("rbind",lapply(split(x,groupvec),colSums,na.rm=T))
>
>
> Thanks reading my question and any hints!
> Werner
>
>
> ---------------------------------
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> 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
>

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm                 


        [[alternative HTML version deleted]]



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 Mon May 15 02:22:35 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 Mon 15 May 2006 - 06:10:07 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.