Meant to write 2nd paragraph as follows : > > Hi. Yes you should be able to rely on that. It's useful to have special > characters in column names for latex formatting, and spaces are allowed > too. There are tests for these things. If you need to refer to such column > names as variables, then it's up to you to wrap with ``; e.g., > by=`Illegal(name%)`+1. > > So yes, if you find problems with special characters, please report as > bugs, and suggest where the documentation needs improving would be great. > > I seem to remember a bug fix in this regard, and in particular in merge > (so my first thought is to ask you if you've recently upgraded to 1.8.2 > and if test.data.table returns 717), but as you say R-Forge is currently > down for maintenance... > > That neworder error looks familiar too. Are you sure you have 1.8.2 > running in memory? (Run test.data.table() to see if it returns 717). > > Matthew > >> I'm taking advantage of a feature in data.table which lets me get away >> with naming columns with characters that would not survive a call to >> make.names(), e.g.: >> >>> DT1 = data.table(a=letters[1:5], "Illegal(name%)"=1:5, key="a") >>> DT1 >> a Illegal(name%) >> 1: a 1 >> 2: b 2 >> 3: c 3 >> 4: d 4 >> 5: e 5 >> >> (The the dcast function from the reshape2 package will also create >> columns >> named "illegally".) >> >> But when using merge.data.table, I get two side-effects; either the >> merge >> works, but the column names appear to be run through make.names(), or >> the >> merge fails in setcolorder(): >> >>> DT1 = data.table(a=letters[1:5], "Illegal(name%)"=1:5, key="a") >>> DT2 = data.table(a=letters[1:5], b=6L, key="a") >> >>> merge(DT1,DT2) >> a Illegal.name.. b >> 1: a 1 6 >> 2: b 2 6 >> 3: c 3 6 >> 4: d 4 6 >> 5: e 5 6 >> >>> merge(DT2,DT1) >> Error in setcolorder(dt, c(setdiff(names(dt), end), end)) : >> neworder is length 4 but x has 3 columns. >> >> I can't get to datatable.r-forge.r-project.org - getting a 504. >> >> So... should I NOT rely on being able to use special characters in >> column >> names? >> >> Thanks >> George >> >>> sessionInfo() >> R version 2.15.0 (2012-03-30) >> Platform: x86_64-unknown-linux-gnu (64-bit) >> [1] data.table_1.8.2 >> _______________________________________________ >> 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 >
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