"Indexing is merging with row numbers, so indeed there's a merging going on" - I hadn't seen it this way until now. But I like this. I see why you expect `nomatch=0` to work on indexing as well. And it makes sense to me.
But I am not so much inclined towards the implementation of `merge`-like operations in X[Y] syntax. I'd love to be convinced. I just can't get my mind around the usage X[Y, all.X = TRUE] and even more X[Y, list(2 columns of X, 1 column of Y), all.X=TRUE]. I could just do Y[X, …] which makes more sense here. I am unable to wrap my head around the need for this feature... Arun On Saturday, May 4, 2013 at 1:54 AM, Gabor Grothendieck wrote: > data.table is supposed to generalize indexing and although not > explicitly stated the generalization seems to be that indexing is > merging with the row numbers so there is indeed merging going on and > that merging should respect nomatch= for consistency. > > On Fri, May 3, 2013 at 6:54 PM, Eduard Antonyan > <[email protected] (mailto:[email protected])> wrote: > > There is no join'ing happening here, thus nomatch=0 has no effect. > > > > > > On Fri, May 3, 2013 at 5:52 PM, Gabor Grothendieck <[email protected] > > (mailto:[email protected])> > > wrote: > > > > > > The definition of DT was left out by mistake. It should be: > > > > > > DT <- data.table(a=letters[1:3]) > > > > > > > > > On Fri, May 3, 2013 at 6:50 PM, Gabor Grothendieck > > > <[email protected] (mailto:[email protected])> wrote: > > > > Consider this example: > > > > > > > > > DT[1:4,,nomatch=0] > > > > a > > > > 1: a > > > > 2: b > > > > 3: c > > > > 4: NA > > > > > > > > Should it not return only the first 3 rows? It seems to be ignoring > > > > the nomatch=0. > > > > > > > > -- > > > > Statistics & Software Consulting > > > > GKX Group, GKX Associates Inc. > > > > tel: 1-877-GKX-GROUP > > > > email: ggrothendieck at gmail.com (http://gmail.com) > > > > > > > > > > > > > > > > > > > -- > > > Statistics & Software Consulting > > > GKX Group, GKX Associates Inc. > > > tel: 1-877-GKX-GROUP > > > email: ggrothendieck at gmail.com (http://gmail.com) > > > _______________________________________________ > > > datatable-help mailing list > > > [email protected] > > > (mailto:[email protected]) > > > > > > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help > > > > -- > Statistics & Software Consulting > GKX Group, GKX Associates Inc. > tel: 1-877-GKX-GROUP > email: ggrothendieck at gmail.com (http://gmail.com) > _______________________________________________ > datatable-help mailing list > [email protected] > (mailto:[email protected]) > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help > >
_______________________________________________ datatable-help mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help
