Perhaps: ?findInterval (you may need to do some type conversion first)
-- Bert On Sat, Jul 27, 2013 at 3:28 PM, John Helly <hel...@ucsd.edu> wrote: > Hi. > > I've been puzzling about how to replace the nested loops below. The idea is > that the B dataframe has rows with a posix datetime and the C dataframes has > posix Start and End times. I want to assign a value to the observations in > B based in intersecting the appropriate time-interval in C. I haven't been > able to discern a more efficient way to do this. Any suggestions would be > most appreciated. > > brows = dim(B)[1] > mrows = dim(C)[1] > > for (i in 1:brows ) { > for (j in 1:mrows ) { > if (B$Datetime[i] >= C$DT_Start[j] & B$Datetime<=C$DT_End[j]){ > B$Site[i] = C$Proximity[j] > } > } > } > > -- > John Helly, University of California, San Diego / San Diego Supercomputer > Center / Scripps Institution of Oceanography / 760 840 8660 mobile / > stonesteps (Skype) / stonesteps7 (iChat) / http://www.sdsc.edu/~hellyj > > > ______________________________________________ > 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. > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.