[datatable-help] What does "problem re-suffixing the merged data.table" mean?

[Steve Lianoglou]

Hi Allan,

On Fri, Aug 5, 2011 at 10:56 AM, Allan Engelhardt (CYBAEA)
<allane at cybaea.com> wrote:
> What does the warning mean?  What sort of problem?
>
> model.data <- merge(Y1, Y2, all = FALSE, suffixes = c(".Y1", ".Y2"))
> Warning message:
> In merge.data.table(Y1, Y2, all = FALSE, suffixes = c(".Y1", ".Y2")) :
>  There was a problem re-suffixing the merged data.table. The merge was
> succesful, but the default column naming has been used (ie. suffixes were
> set to c('', '.1').
>
> It doesn't seem to matter what value I use for suffixes=

When I added the ability to add custom suffixes, I added that warning
if the logic I used to slap the right suffixes on the right columns
hit a corner case that I didn't expect. The warning was so you could
do what you did an report a problem so the logic could be revisited.

Also, the merge actually "worked", though, the data.table that comes
back is the one you would have gotten if you set the suffixes param to
c("", ".1") [which was essentially what was happening before custom
suffixes were supported).

All that having been said, I recently checked in a fix for one of
these corner cases that made it's way into data.table 1.6.3. Could you
update to 1.6.3 to see if it works for you?

If it doesn't, can you provide the column names of the two data.tables
you are trying to merge on, and what the value is for your `by` param?

Thanks,
-steve

-- 
Steve Lianoglou
Graduate Student: Computational Systems Biology
 | Memorial Sloan-Kettering Cancer Center
 | Weill Medical College of Cornell University
Contact Info: http://cbio.mskcc.org/~lianos/contact