try this: > # create a factor and then convert back to numeric > x$nb <- as.integer(factor(x$name, levels=unique(x$name))) + 99 > x name freq nb 1 Mary 1 100 2 Mary 2 100 3 Mary 3 100 4 Sam 1 101 5 Sam 2 101 6 John 1 102 7 John 2 102 8 John 3 102 9 John 4 102
On Sat, Nov 21, 2009 at 7:00 PM, Dana Sevak <[email protected]> wrote: > Dear R Helpers, > > I am missing something very elementary here, and I don't seem to get it from > the help pages of the ave, seq and seq_along functions, so I wonder if you > could offer a quick help. > > To use an example from an earlier post on this list, I have a dataframe of > this kind: > > dat = data.frame(name = rep(c("Mary", "Sam", "John"), c(3,2,4))) > dat$freq = ave(seq_along(dat$name), dat$name, FUN = seq_along) > > dat > name freq > 1 Mary 1 > 2 Mary 2 > 3 Mary 3 > 4 Sam 1 > 5 Sam 2 > 6 John 1 > 7 John 2 > 8 John 3 > 9 John 4 > > What I need is another column assigning a number to each name starting from > index 100, that is: > > name freq nb > 1 Mary 1 100 > 2 Mary 2 100 > 3 Mary 3 100 > 4 Sam 1 101 > 5 Sam 2 101 > 6 John 1 102 > 7 John 2 102 > 8 John 3 102 > 9 John 4 102 > > What is the easiest way to do this? > > Thanks a lot for your kind help. > > Dana > > ______________________________________________ > [email protected] 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ [email protected] 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.
