Hi I named your data test
test$x<-1 test$x<-unlist(lapply(split(test$x, test$id.name), cumsum)) > test id.name x 1 123.45 1 2 123.45 2 3 123.45 3 4 123.45 4 5 234.56 1 6 234.56 2 7 234.56 3 8 234.56 4 9 234.56 5 10 234.56 6 11 234.56 7 12 345.67 1 13 345.67 2 14 345.67 3 15 456.78 1 16 456.78 2 17 456.78 3 18 456.78 4 19 456.78 5 20 456.78 6 21 456.78 7 22 456.78 8 23 456.78 9 > Two comments: This works only when your data are sorted Beware of FAQ 7.31 Regards Petr > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Steven Ranney > Sent: Friday, October 11, 2013 3:26 PM > To: r-help@r-project.org > Subject: [R] Create sequential vector for values in another column > > Hello all - > > I have an example column in a dataFrame > > id.name > 123.45 > 123.45 > 123.45 > 123.45 > 234.56 > 234.56 > 234.56 > 234.56 > 234.56 > 234.56 > 234.56 > 345.67 > 345.67 > 345.67 > 456.78 > 456.78 > 456.78 > 456.78 > 456.78 > 456.78 > 456.78 > 456.78 > 456.78 > ... > [truncated] > > And I'd like to create a second vector of sequential values (i.e., 1:N) > for each unique id.name value. In other words, I need > > id.name x > 123.45 1 > 123.45 2 > 123.45 3 > 123.45 4 > 234.56 1 > 234.56 2 > 234.56 3 > 234.56 4 > 234.56 5 > 234.56 6 > 234.56 7 > 345.67 1 > 345.67 2 > 345.67 3 > 456.78 1 > 456.78 2 > 456.78 3 > 456.78 4 > 456.78 5 > 456.78 6 > 456.78 7 > 456.78 8 > 456.78 9 > > The number of unique id.name values is different; for some values, > nrow() may be 42 and for others it may be 36, etc. > > The only way I could think of to do this is with two nested for loops. > I tried it but because this data set is so large (nrow = 112,679 with > 2,161 unique values of id.name), it took several hours to run. > > Is there an easier way to create this vector? I'd appreciate your > thoughts. > > Thanks - > > SR > Steven H. Ranney > > [[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. ______________________________________________ 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.
