[R] Merging two datasets

rkevinburton at charter.net rkevinburton at charter.net
Wed Aug 6 18:10:16 CEST 2008


I looked at 'merge'. What if df1 and df2 are data.frames and I want to merge on on column and sum on another? Say df1 and df2 are data.frames with columns 'ID1', 'ID2', 'ID3', and 'Qty'. I want to 'merge' the data frames (and produce a new data.frame) if there is a matching 'ID2' in each data.frame and if there is sum the 'Qty' value from each data fame. First, I don't see a function that can be applied during the merge. Maybe that has to be done in a separate step. Next, 'merge' seems to produce a data.frame with the columns renamed. How can I preserve the column names?

Thank you.


Kevin

---- Henrique Dallazuanna <wwwhsd at gmail.com> wrote: 
> Try using:
> 
> merge(df1, df2, all = TRUE)
> 
> On Wed, Aug 6, 2008 at 11:15 AM, Shreyasee Pradhan
> <shreyasee.pradhan at gmail.com> wrote:
> > I am facing a problem in merging two datasets.
> > I have given codes to the names which are common in both the datasets and
> > also to those which are uncommon.
> > When I gave gave the following command
> >
> > merge(df1,df2)
> >
> > only those rows and columns were merged which were  having common codes.
> > When I viewed the results, only common codes are seen and the remaining
> > entries are not seen.
> >
> > Can anyone guide me in this regards?
> > How should I merge these two datasets completely without loss of any
> > information?
> >
> > Thanks,
> > Shreyasee
> >
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
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> > and provide commented, minimal, self-contained, reproducible code.
> >
> 
> 
> 
> -- 
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.



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