?split -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111
> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Jonathan Greenberg > Sent: Thursday, July 28, 2011 2:14 PM > To: r-help > Subject: [R] Data frame to list > > I'm hoping this is an easy problem that I'm missing something obvious. > Given: > > x=c(1,1,1,2,2,3,3,3) > y=c(1:length(x)) > dataframe=data.frame(x,y) > > I would like to convert this to a list for use with certain functions, > where each entry of the list is a subsetted dataframe based on > dataframe$x > > I can do this "brute force" by a for-next loop: > > unique_x=unique(dataframe$x) > unique_x_N=length(unique_x) > dataframe_to_list=vector(mode="list",length=unique_x_N) > for(i in 1:unique_x_N) > { > dataframe_to_list[[i]]=subset(dataframe,x==unique_x[i]) > > } > > My R-gut is telling me there's a much more efficient way of doing this > -- is it right? > > --j > > ______________________________________________ > 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. ______________________________________________ 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.
