[R] problems with merge() - the output has many repeated lines

[Cecilia Carmo]

Thanks, but I don't have multiple matches and the lines 
repeated in the final dataframe are exactly equal in all 
columns.

Cecília

Sat, 21 Aug 2010 10:58:53 -0500
  Hadley Wickham <hadley at rice.edu> escreveu:
> You may find a close reading of ?merge helpful, 
>particularly this
> sentence: "If there is more than one match, all possible
> matches contribute one row each"  (so check that you 
>don't have
> multiple matches).
> 
> Hadley
> 
> On Sat, Aug 21, 2010 at 10:45 AM, Cecilia Carmo 
><cecilia.carmo at ua.pt> wrote:
>> Hi everyone,
>>
>> I have been merging many big dataframes (about 80000 
>>rows each) and I never
>> had this problem, but now it happened to me and I want 
>>to know if someone
>> knows what could be happening.
>> The final dataframe has many rows, an impossible number! 
>>I have done
>> edit(dataframe) and I saw that there are many repeated 
>>rows (all equal).
>>
>> Thanks for any help,
>>
>> Cecília Carmo
>> Universidade de Aveiro
>> Portugal
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide 
>>http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, 
>>reproducible code.
>>
> 
> 
> 
> -- 
> Assistant Professor / Dobelman Family Junior Chair
> Department of Statistics / Rice University
> http://had.co.nz/