Re: [R] how to simplify a data.frame and add the counts of duplicate rows as a new column

2011-03-02 Thread Simone Gabbriellini
many thanks, this is really a great solution! best, Simone Il giorno 02/mar/2011, alle ore 16.22, Scott Chamberlain ha scritto: > see package plyr, especially the function ddply(), eg.., in your case: > > ddply(dataframe, .(columnA, columnB), summarise, > columnC = length(columnB) > ) >

Re: [R] how to simplify a data.frame and add the counts of duplicate rows as a new column

2011-03-02 Thread Scott Chamberlain
see package plyr, especially the function ddply(), eg.., in your case: ddply(dataframe, .(columnA, columnB), summarise, columnC = length(columnB) ) Scott On Wednesday, March 2, 2011 at 9:10 AM, Simone Gabbriellini wrote: > Hello List, > > I would like to simplify a data.frame like this > > co

[R] how to simplify a data.frame and add the counts of duplicate rows as a new column

2011-03-02 Thread Simone Gabbriellini
Hello List, I would like to simplify a data.frame like this columnA columnB user10 proj12 user10 proj19 user10 proj12 into something like: columnA columnB columnC user10 proj12 2 user10 proj19 1 I know unique() can simplify the dat