[datatable-help] Crash when assigning column.

[Matthew Dowle]

Hi,

Yes that warning was because Ricky supplied the output of dput to 
create the example data, which uses structure(). Creating a data.table 
that way doesn't initialize the .internal.selfref. I usually just 
replace the structure() with a data.table() call when pasting code like 
that.

Have now improved that warning :

     " ... At an earlier point, this data.table has been copied by R (or 
been created manually using structure() or similar). Avoid ..."

and the result looks correct to me in v1.8.7.

Thanks,
Matthew

On 21.01.2013 19:42, statquant3 wrote:
> As Matthew is saying, I am using v.1.8.7 (lattest release)
> I get a warning:
>
> R>   test.dt[, tc := which(name==order), by=list(ID, name)]
> Warning message:
> In `[.data.table`(test.dt, , `:=`(tc, which(name == order)), by = 
> list(ID,
> :
>   Invalid .internal.selfref detected and fixed by taking a copy of 
> the whole
> table, so that := can add this new column by reference. At an earlier 
> point,
> this data.table has been copied by R. Avoid key<-, names<- and attr<- 
> which
> in R currently (and oddly) may copy the whole data.table. Use set* 
> syntax
> instead to avoid copying: setkey(), setnames() and setattr(). Also,
> list(DT1,DT2) will copy the entire DT1 and DT2 (R's list() copies 
> named
> objects), use reflist() instead if needed (to be implemented). If 
> this
> message doesn't help, please report to datatable-help so the root 
> cause can
> be fixed.
>
>
>
>
> --
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