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st: Generating unique values from unique and duplicate cases
From
Tim Morris <[email protected]>
To
[email protected]
Subject
st: Generating unique values from unique and duplicate cases
Date
Mon, 17 Oct 2011 15:49:42 +0100
Hello,
I have created syntax to check for and label potential duplicate cases
across 3 variables (two text and one numeric). the syntax is as follows:
sort var1 var2 var3
quietly by var1 var2 var3: gen dup = cond(_N==1,0,_n) if var1!=. |
var2!="" | var3!=""
this results in a new variable (dup) which may read as follows through the
cases: 0, 0, 0, 1, 2, 0, 0 (1 and 2 being duplicate cases the rest being
unique). What i want to do is create a new variable (id) that assigns a
unique id to each unique case and groups together the corresponding
duplicates into the same id, so based upon the example above the results
will be along the lines of:
dup id
0 1
0 2
0 3
1 4
2 4
0 5
0 6
I have played around with various code, searched online and spoken to other
STATA users for help but cannot find a way to make STATA assign unique
values for each 'group' of duplicates. Thanks in advance for any help.
regards,
tim morris
----------------------
Tim Morris, ALSPAC
[email protected]
0117 331 0022
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