Laetitia Marisa wrote: > Hello, > > Is there a simple and fast function that returns a vector of the number > of replications for each object of a vector ? > For example : > I have a vector of IDs : > ids <- c( "ID1", "ID2", "ID2", "ID3", "ID3","ID3", "ID5") > > I want the function returns the following vector where each term is the > number of replicates for the given id : > c( 1, 2, 2, 3,3,3,1 )
One-liner: > table(ids)[ids] ids ID1 ID2 ID2 ID3 ID3 ID3 ID5 1 2 2 3 3 3 1 'table(ids)' computes the counts, then the subscripting [ids] looks it all up. Now try it on your 40,000-long vector! Barry ______________________________________________ [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
