Hi, You should use the sapply/lapply for such operations. > r<-round(runif(100000,1,10)) > head(r) [1] 3 7 6 3 2 8 > filt<-function(x,thres) ifelse(x<thres,x,thres) > system.time(r2<-sapply(r,filt,thres=5)) user system elapsed 3.36 0.00 3.66 > head(r2) [1] 3 5 5 3 2 5
To return a list, replace "sapply" with "lapply" Christos > Date: Mon, 21 Jun 2010 11:34:01 +0100 > From: ja...@ipec.co.uk > To: r-help@r-project.org > Subject: [R] Replacing elements of a list over a certain threshold > > Dear List, > > I have a list of length ~1000 filled with numerics. I need to replace > the elements of this list that are above a certain numerical threshold > with the value of the threshold. > > e.g > example=list(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1) > threshold=5 > <magic code goes here> > example=(1, 2, 3, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 3, 2, 1). > > I have written a crude script that achieves this but it's very slow. Is > there a way to do this using some R function? > > Crude script: http://pastebin.com/3KSfi8nD > > ______________________________________________ > 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. _________________________________________________________________ Hotmail: Free, trusted and rich email service. [[alternative HTML version deleted]] ______________________________________________ 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.
