Re: [Gretl-users] Computing an index for unique combinations of discrete variables

Yes, nice, but one has to check that 'region' and 'sector' do not share a common cluster ID like in <hansl> region = randgen(i,1,10) sector = randgen(i,1,5) <hansl> Since combinations like (1,2) and (2,1) are treated as being different. Hence, with a primary data manipulation 'sector = randgen(i,1,5) +100' things should be fine. 21.11.2013 15:13, Riccardo (Jack) Lucchetti: > On Thu, 21 Nov 2013, Giuseppe Vittucci wrote: > > > Hi, > > > > I have firm level data and two categorical variables (region and > > sector). > > I need to define another variable which is an index identifying > > the > > unique combinations region-sector each firm belongs to, so I can > > use it > > in computing cluster-robust s.e. > > > > One way to do this is to use the command "values" for region and > > sector > > and then use a nested loop, but this seems quite > > time-consuming... > > > > Is there a simpler way in gretl to do it? > > You mean, like this? > > <hansl> > nulldata 1024 > > # simulated data > region = randgen(i,1,20) > sector = randgen(i,10,99) > # ---------------------------------------------- > scalar ndigits = floor(log10(max(sector))) > series unique = region * 10^(ndigits+1) + sector > </hansl> > > > ------------------------------------------------------- > Riccardo (Jack) Lucchetti > Dipartimento di Scienze Economiche e Sociali (DiSES) > > Università Politecnica delle Marche > (formerly known as Università di Ancona) > > r.lucchetti(a)univpm.it > http://www2.econ.univpm.it/servizi/hpp/lucchetti > ------------------------------------------------------- > > > _______________________________________________ > Gretl-users mailing list > Gretl-users(a)lists.wfu.edu > http://lists.wfu.edu/mailman/listinfo/gretl-users _______________________________________________ Gretl-users mailing list Gretl-users(a)lists.wfu.edu http://lists.wfu.edu/mailman/listinfo/gretl-users