[R] How to combine two data frames by ID

jim holtman
Wed, 15 Jul 2009 01:24:35 -0000

?merge

On Tue, Jul 14, 2009 at 9:07 PM, Christopher
Desjardins<cddesjardins at gmail.com> wrote:
> Hi,
>
> I am trying to combine two data frames by ID. The first data frame is the
> whole data set and the second data frame is a subset of the first. What I
> would like to do is take the values from variable, p1, from the second data
> frame and merge them back into that variable in the first data frame. I
have
> ID variables that match for both data frames and the data frames obviously
> have differing number of rows where the first data frame > second data
> frame. I want to keep the pre existing data for this variable that is
> present in the first data frame and only write over the data that I edited
> in the second.
>
> Thanks and please cc me as I am a digest subscriber,
> Chris
>
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--
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?