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 2ã 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]]
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