Thanks a lot. This is working for me. Thanks and regards,
On Sun, Nov 17, 2013 at 4:41 AM, Arunkumar Srinivasan <[email protected] > wrote: > How about this? > DT[CJ(c("a", "b"), c("B", "D"))] > > Arun > > On Saturday, November 16, 2013 at 11:53 PM, Christofer Bogaso wrote: > > Hello all, > > I am a new user of data.table and really started to liking it :) > > I am seeking some suggestion on how I can implement 'OR'/AND' operator to > fetch a subset of a data.table. > > Below is my example data.table (my actual data.table is quite big): > > DT = data.table(x = 1:20, y1 = rep(letters[1:4], 5), y2 = > rep(LETTERS[1:4], each = 5)) > setkey(DT, y1, y2) > > > DT > x y1 y2 > 1: 1 a A > 2: 5 a A > 3: 9 a B > 4: 13 a C > 5: 17 a D > 6: 2 b A > 7: 6 b B > 8: 10 b B > 9: 14 b C > 10: 18 b D > 11: 3 c A > 12: 7 c B > 13: 11 c C > 14: 15 c C > 15: 19 c D > 16: 4 d A > 17: 8 d B > 18: 12 d C > 19: 16 d D > 20: 20 d D > > > Now I want to fetch those rows for which "y1 = a OR b AND y2 = B OR D" > > with ordinary data.frame, this is straightforward to achieve, however I am > wondering what could be the data.table way for fast computation. > > I would really appreciate for your help/pointer. > > Thanks and regards, > > _______________________________________________ > datatable-help mailing list > [email protected] > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help > > >
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