[R] how to combine two data frames via factors (or somehow else)

[Phil Spector]

Philipp -
    I believe you're looking for the merge function.
If you need more guidance, please provide a meaningful
reproducible example.
 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu

On Mon, 30 May 2011, Philipp Chapkovski wrote:

> Hello!
> The question should be very naive, but I am a beginner and stuck with
> this unfortunately.
> There is a dataset of people's affiliation to companies that looks
> like that (a data frame actually)
>  x y
> 1 a X
> 2 b X
> 3 c X
> 4 f Z
> 5 e Z
> 6 g Z
> where x is a name of a person and y is a company name. That is, a,b,c
> work in a company X. f,e,g work in a company Z.
>
> and there is another dataset with the affiliation of companies. Like
> that (much much longer in reality):
>  y1 y2
> 1  X W
> 2  Z W
> that means that both X and Z belongs to the same company W.
> What is the most compact way (without loops etc) to 'attach' the 'head
> company' from the second dataset to the first dataset so I can have
> something like:
>
>  x  y owner
> 1 a X W
> ...
> 4 f  Z W
>
> I know it should be done somehow with factors, but I don't know how.
> Thank you in advance!
>
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