|
Hi, is there any way to prevent name-munging when [] is used? The
data.table constructor supports check.names but as soon as a join is performed the names are munged. Thanks. _______________________________________________ datatable-help mailing list [hidden email] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help |
|
name-munging? Example please.
On Thu, 2012-03-08 at 15:06 -0800, Yang Zhang wrote: > Hi, is there any way to prevent name-munging when [] is used? The > data.table constructor supports check.names but as soon as a join is > performed the names are munged. Thanks. > _______________________________________________ > datatable-help mailing list > [hidden email] > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help _______________________________________________ datatable-help mailing list [hidden email] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help |
|
Oh, an example is when I have a column named "Account Name" it gets
munged into "Account.Name". That's why I was referring to the check.names argument (same as in other places like read.table). Actually, I think I was mistaken in thinking that data.table supported un-munged names at all - I'm not in front of R at the moment but IIRC when I ran data.table(data.frame('a b'=1), check.names=F) I would get a column named "a.b". But I could be completely wrong. In any case I'm pretty sure after using operator [] any un-munged names get munged. Thanks On Thu, Mar 8, 2012 at 4:37 PM, Matthew Dowle <[hidden email]> wrote: > name-munging? Example please. > > On Thu, 2012-03-08 at 15:06 -0800, Yang Zhang wrote: >> Hi, is there any way to prevent name-munging when [] is used? The >> data.table constructor supports check.names but as soon as a join is >> performed the names are munged. Thanks. >> _______________________________________________ >> datatable-help mailing list >> [hidden email] >> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help > > -- Yang Zhang http://yz.mit.edu/ _______________________________________________ datatable-help mailing list [hidden email] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help |
|
Munged is a slightly strong word to describe that. Similar to mangled.
The thinking behind it is to encourage j expressions of column names, like a database. So column names need to be valid variable names. However thinking about it, perhaps data.table shouldn't force that on user. Writing from phone so perhaps you could raise a detailed bug or feature request. > Oh, an example is when I have a column named "Account Name" it gets > munged into "Account.Name". That's why I was referring to the > check.names argument (same as in other places like read.table). > > Actually, I think I was mistaken in thinking that data.table supported > un-munged names at all - I'm not in front of R at the moment but IIRC > when I ran data.table(data.frame('a b'=1), check.names=F) I would get > a column named "a.b". But I could be completely wrong. > > In any case I'm pretty sure after using operator [] any un-munged > names get munged. > > Thanks > > On Thu, Mar 8, 2012 at 4:37 PM, Matthew Dowle <[hidden email]> > wrote: >> name-munging? Example please. >> >> On Thu, 2012-03-08 at 15:06 -0800, Yang Zhang wrote: >>> Hi, is there any way to prevent name-munging when [] is used? The >>> data.table constructor supports check.names but as soon as a join is >>> performed the names are munged. Thanks. >>> _______________________________________________ >>> datatable-help mailing list >>> [hidden email] >>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help >> >> > > > > -- > Yang Zhang > http://yz.mit.edu/ > _______________________________________________ datatable-help mailing list [hidden email] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help |
| Powered by Nabble | Edit this page |
