See FAQ 2.14 http://datatable.r-forge.r-project.org/datatable-faq.pdf
On 05/04/2014 02:00 PM, Rguy wrote: > I am beginning to learn the data.table package. At the outset, > 'data.table.pdf' states: > > It is inspired by A[B] syntax in R where A is a matrix and B is a 2-column > matrix. > > I have used matrices in R but am unfamiliar with the A[B] syntax. When I > check the documentation for 'matrix' I find no discussion of such syntax. So > this "explanation" is in fact a black hole. Please tell your readers what > the package does in such a way that they are not sent on a wild goose chase. > For example: > > The data.table package supports an A[B] syntax where A is a data table, B is > a 2 column data table, and the effect of the expression A[B] is... > > What does A[B] accomplish? > > Thanks. > > > > > -- > View this message in context: http://r.789695.n4.nabble.com/A-B-tp4689942.html > Sent from the datatable-help mailing list archive at Nabble.com. > _______________________________________________ > datatable-help mailing list > [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
