[R] Adding two files into one and vlookup

[Raghu]

Say I have two files file and file2:

file1 contains the following:
Date	                Price
02/07/2010	53.96597903
03/07/2010	56.92825807
04/07/2010	39.27408645
05/07/2010	42.59834151
06/07/2010	70.68512383
07/07/2010	10.92505265
08/07/2010	52.12492249
09/07/2010	49.88767957

file2 contains the following:
Date	                Price
03/07/2010	5.312006403
04/07/2010	673.0705924
05/07/2010	442.4679386
06/07/2010	851.9158985
07/07/2010	581.8592424

I want to create a new file that should look like:
Date                  Price1                Price2
03/07/2010	5.312006403        56.928
04/07/2010	673.0705924        39.274
05/07/2010	442.4679386        42.598
06/07/2010	851.9158985        70.685
07/07/2010	581.8592424        10.925

Thx



On 7/7/10, Erik Iverson <eriki at ccbr.umn.edu> wrote:
> raghu wrote:
>> I have two files with dates and prices in each. The number of rows in each
>> of
>> them will differ. How do I create a new file which contains data from both
>> these files? Cbind and merge are not helpful. For cbind because the rows
>> are
>> not the same replication occurs. Also if I have similar data how do I
>> write
>> a vlookup kind of function? I am giving an example below:
>> Say Price1 file contains the following:
>> Date             Price
>> 2/3/2010       134.00
>> 3/3/2010       133.90
>> 4/3/2010       135.55
>>
>> And say price2 contains the following:
>> Date              Price
>> 2/3/2010        2300
>> 3/3/2010        3200
>> 4/3/2010        1800
>> 5/3/2010        1900
>>
>> I want to take both these data together in a single file, and take the
>> smaller vector (or matrix or dataframe??..i am new to R and still confused
>> with the various objects) which is file1 (because it contains fewer rows )
>> and vlookup prices in the second file basedon the dates on file1 and write
>> three columns (date, price from 1 and price from2) in a new file. How do i
>> do this please?
>
> I think all this can be accomplished with merge.  Can you give reproducible
> examples as the posting guide suggests?
>
> Use read.table to read in your data into R objects, then use ?dput to give
> us
> the exact copies of the objects (probably data.frames by your example), and
> what
> output you want to have.  Being precise with the classes of objects you're
> working with is key, and ?dput is a great way to make sure we have the same
> objects as you.
>
> Another tip is common terminology. For instance, `vlookup` is not a term
> used in
> R, and many people will not know what it means.
>
> This way, everything is reproducible for us, and we can offer suggestions
> and
> show you what the exact output will be.  In short, making sure everyone is
> on
> the same page goes a long way when getting help from a mailing list.
>
>


-- 
'Raghu'