apply over parallel lists and their elements
On Sep 13, 2010, at 5:20 PM, Liviu Andronic wrote:
Hello On Sun, Sep 12, 2010 at 5:37 PM, Sebastian Gibb <lists at sebastiangibb.de
wrote: Hello, thanks for your answer. mapply fits to my needs.
One thing that seems strange is that if you use tree[[1]]$node$values <- 1:10 tree[[2]]$node$values <- 3:12 you still get
mapply(mean, tree[[1]]$node$values, tree[[2]]$node$values)
[1] 1 2 3 4 5 6 7 8 9 10 But I cannot understand what's wrong.
The second argument to mean is trim. I am not sure what mean(1, 3) is supposed to do but what it return is 1. If you wanted 2,3,4 ..., 11 then you would perhaps do: mean( mapply(c, tree[[1]]$node$values, tree[[2]]$node$values) )
David > > >> But I don't know how many items would "tree" have. I can't write >> them all by >> hand. >> How can I generate the arguments for mapply? >> > Unfortunately I cannot think of a solution. Perhaps reorganise your > data, so that all relevant data points go into the same vector. For > example, > tree[[4]]<-list(); > tree[[4]][['node']]<-list(); > tree[[4]]$node$more[[1]] <- 1:10 > tree[[4]]$node$more[[2]] <- 3:12 >> mapply(mean, tree[[4]]$node$more) > [1] 5.5 7.5 > > Also check maply and mlply to see if they can fit your needs. [1] > Regards > Liviu > > [1] http://had.co.nz/plyr/plyr-intro-090510.pdf > > > >> mapply(mean, tree[[1]]$node$values, tree[[2]]$node$values, ... >> tree[[k]]$node$values); >> >> Kind regards, >> >> Sebastian >> >> ______________________________________________ >> R-help at 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. >> > > > > -- > Do you know how to read? > http://www.alienetworks.com/srtest.cfm > http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader > Do you know how to write? > http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail > > ______________________________________________ > R-help at 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. David Winsemius, MD West Hartford, CT