[R] (Newbie) Merging two data frames
Marc Schwartz (via MN)
mschwartz at mn.rr.com
Wed Feb 1 23:19:34 CET 2006
On Wed, 2006-02-01 at 17:10 -0500, Vivek Satsangi wrote:
> This one is an easy question. I am looking for the "idiomatic" way to do it.
>
> I have two large data frames. I want to "merge" them. What is the
> idiomatic way to say "match the rows from dataframe 1 to the rows in
> dataframe2 which have the following fields the same: Identifier, Year
> and Quarter? (These three fields form something like a composite
> primary key in SQL). Then tell me which rows you could not find a
> match for.... etc.
You answered your own question... :-)
See ?merge
which will perform SQL-like joins.
HTH,
Marc Schwartz
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