[R] Merging dataframes

[Chintanu]

Thanks - Peter, Eivind, Rui


Sorry, I perhaps could not explain it properly in the first go.

Trying to simplify it here with an example - Say I have two dataframes as
below that are NOT equally-sized data frames (i.e., number of columns are
different in each table):



Table_A:

Email             Name                   Phone

abc using gmail.com   John Chan         0909

bcd using yahoo.com   Tim Ma                    89089

......



Table_B:

Email                     Name                 Sex        Phone

abc using gmail.com    John Chan            M                 0909

khn using hotmail.com           Rosy  Kim               F                   7779

.....



Now, I have used -

merge (Table_A, Table_B, by="Email", all = FALSE))



- to find only the rows that match from these data frames - based on Email
as primary key.



Further, I am also interested (using "Email" as the common key) which rows
from Table_A did not match with Table_B.

I am not sure how to do this here.

Thanks and regards,
Chintanu



On Tue, May 1, 2018 at 8:48 PM, Rui Barradas <ruipbarradas using sapo.pt> wrote:

> Hello,
>
> Is it something like this that you want?
>
> x <- data.frame(a = c(1:3, 5, 5:10), b = c(1:7, 7, 9:10))
> y <- data.frame(a = 1:10, b = 1:10)
>
> which(x != y, arr.ind = TRUE)
>
>
> Hope this helps,
>
> Rui Barradas
>
>
> On 5/1/2018 11:35 AM, Chintanu wrote:
>
>> Hi,
>>
>>
>> May I please ask how I do the following in R. Sorry - this may be trivial,
>> but I am struggling here for this.
>>
>>
>>
>> For two dataframes (A and B), I wish to identify (based on a primary
>> key-column present in both A & B) -
>>
>> 1. Which records (rows) of A did not match with B, and
>>
>>
>>
>> 2. Which records of B did not match with A ?
>>
>>
>>
>> I came across a setdt function while browsing, but when I tried it, it
>> says
>> - Could not find function "setdt".
>>
>>
>>
>> Overall, if there is any way of doing it (preferably in some simplified
>> way), please advise.
>>
>>
>> Many thanks in advance.
>>
>>
>> regards,
>>
>> Tito
>>
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>>
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