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Re: st: Fwd: Mergeing datasets
From
Lars Ängquist <[email protected]>
To
<[email protected]>
Subject
Re: st: Fwd: Mergeing datasets
Date
Sat, 30 Apr 2011 01:49:51 +0200
Dear Thomas.
This seems to be solved by an application of the - reshape long -
functionality. Try, with respect to the former dataset, stating
reshape long id, i(master) j(nbr)
and you are already there (without even considering the latter id-based
dataset). However, if the latter one additionally includes other variables
of interest then you can simply apply a - merge - as a second step
use data1, clear
merge 1:1 id using data2
where the former and latter datasets here are referred to as 'data1' and
'data2' respectively. Moreover, I have here assumed that the id:s originally
distributed over id1-id4 are unique within the corresponding data matrix
(though this is in principle not important; if not being true, simply use -
merge 1:m - or - merge m:1 - instead). One may also note that the derived
variable 'nbr' will, prepared to being used if needed, hold the information
on from which original id-variable each id-value originates (here through
integers 1-4).
I hope this will help you solving your problem.
With best wishes & regards / Lars Ängquist
-------- Original Message --------
Subject: Mergeing datasets
Date: Tue, 26 Apr 2011 16:17:47 -0600
From: Thomas Speidel <[email protected]>
To: <[email protected]>
Reply-To: [email protected]
I have a dataset containing mappings of various id's used in a study. The
truly unique person identifier is the variable master. A person may then be
assigned an id:
master id1 id2 id3 id4
106 708 673 . 676
110 713 696 . 704
122 721 721 . .
123 749 722 . 728
129 789 789 734 .
134 739 739 . .
144 800 752 . 763
145 808 753 . 780
151 797 764 . 781
158 811 771 . 779
I have a working dataset containg id. The id may come from id1, id2, id3, or
id4 above:
. list id in 1/10, clean noobs
id
2014
2030
2038
2041
2042
2054
2055
2058
2061
2065
I need to merge(?) the two so that I can get the master id for each id,
regardless of whether they came from id1 id2 id3 id4. I thought this was a
job for merge, but did not find a mention for this type of situations in the
manual. I suppose I could do four sequential merges. Any suggestion on how
to best proceed?
Thanks.
--
Thomas Speidel
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