Try this: subset(merge(X, Y, by.x = 'groups', by.y = 1, all = TRUE), values < V2, -V2)
On Wed, Oct 20, 2010 at 1:37 PM, swam <sundars...@yahoo.com> wrote: > > I am needing some help in removing certain rows in a data.matrix and then > do > some calculation. So Iam need to removing certain values above a threshold > or value from another vector. > > For eg.. in the below data matrix X there are 6 groups (A, B, C, D, E ,F) > > >X > rows groups values > 1 A 1.2 > 2 A 0.2 > 3 A 6 > 4 A 0.5 > 5 A 22 > 6 B 0.2 > 7 B 1 > 8 C 0.5 > 9 D 5 > 10 D 4 > 11 D 40 > 12 E 0.3 > 13 E 0.5 > 14 E 1 > 15 E 1.1 > 16 E 0.9 > 17 E 4 > 18 F 0.22 > 19 F 0.32 > 20 F 1.5 > > > I have another array Y with 6 values (equal to the number of groups in X). > I need to remove the rows in each group in X that is greater than the first > value in Y for Group A in X and similarly for group B and so on .. > > >Y > > > A 1.5 > B 1.1 > C 0.8 > D 6 > E 2 > F 1.9 > > > For eg any value greater than 1.5 (from vector Y) must be removed in > Matrix > X only for group A. similarly for all, hence the result will be like the > matrix shown below > > rows groups values > 1 A 1.2 > 2 A 0.2 > 3 A 6 > 4 A 0.5 > 5 B 0.2 > 6 B 1 > 7 C 0.5 > 8 D 5 > 9 D 4 > 10 E 0.3 > 11 E 0.5 > 12 E 1 > 13 E 1.1 > 14 E 0.9 > 15 F 0.22 > 16 F 0.32 > 17 F 1.5 > > > I tried to get this with no luck any help would be appreciated. > > swam > > > -- > View this message in context: > http://r.789695.n4.nabble.com/removing-rows-from-a-matrix-using-condition-within-groups-tp3004132p3004132.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[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.
