Hi Melanie, I think you just need merge(TABLE1, TABLE2)
see ?merge for details. -Ista On Wed, Mar 10, 2010 at 12:47 AM, Melanie HAMEL <melanie.ha...@ird.fr> wrote: > Dear all, > > I would like to solve a trivial problem (I guess it is) but can't find the > right way. Maybe someone can help me ? > > I've got a table with two factors (station = station ID, buffer = buffer size > in meters) and a value for each unique combination of those two factors (S = > number of habitats within each buffer around each station) like this: > > TABLE 1 > > station buffer S > > Abaia01 200 2 > Abaia01 400 2 > Abaia01 600 2 > Abaia01 800 2 > Abaia01 1000 2 > Abaia01 1200 2 > Abaia01 1400 2 > Abaia01 1600 2 > Abaia01 1800 2 > Abaia01 2000 2 > Abaia02 200 2 > Abaia02 400 2 > Abaia02 600 2 > Abaia02 800 2 > Abaia02 1000 2 > Abaia02 1200 2 > Abaia02 1400 2 > Abaia02 1600 2 > Abaia02 1800 3 > Abaia02 2000 3 > > > etc.. > > I would like to fill this more complete table here wich has a third factor > "L5_code" (L5_code = type of habitat). As you can see, there are several > types of habitats within each buffer around a station (up to several dozens). > > TABLE 2 > > station buffer L5_CODE S > > Abaia01 200 14 2 > Abaia01 200 11 2 > > Abaia01 400 14 2 > Abaia01 400 11 2 > > > Abaia01 600 14 2 > Abaia01 600 11 2 > > > ... ... ... > > > Abaia02 200 14 2 > Abaia02 200 11 2 > > > Abaia02 400 14 2 > Abaia02 400 11 2 > > > Abaia02 600 14 2 > Abaia02 600 11 2 > > I was hoping there was a simple function to do that but for now I've been > useless with bad for loops, etc. > > One method could be to go go through TABLE 1 step by step then fill TABLE 2 > according to a combination of station and buffer of TABLE 1. I.e. go through > the first column of TABLE 2 and find the corrseponding station name from > TABLE 1, then go through the second column of TABLE 2 and find the > corresponding buffer size from TABLE 1, then rep() the value of TABLE 1 in > the column S of TABLE 2 corresponding to the right combination... > > One other (quick) method would be to create a unique factor from the two > first columns of TABLE 1 (station_buffer) but maybe there is something > cleaner ? Do you have an idea ? > > Thanks ! > > Mel > > PS: those tables are supposed to be very large datasets of several thousands > of rows. > > > ___________________________________________________ > > Mélanie HAMEL > Institut de Recherche pour le Développement (I.R.D.) > U227 - CoRéUs (Biocomplexité des Ecosystèmes Coralliens de l'Indo-Pacifique) > > Centre IRD - Nouméa > 101 Promenade Roger Laroque > Anse Vata > BP A5 - 98848 Noumea > New Caledonia > > Tel: 26 07 19 > E-mail: melanie.ha...@ird.fr > Web: http://www.coreus.ird.fr > > _______________________________________________________________________ > Save a tree, please don't print this email unless you really need to... > > [[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. > > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ 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.
