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Re: st: If variable x contains variable y


From   Christoph Engel <engel@coll.mpg.de>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: If variable x contains variable y
Date   Sun, 15 Jul 2012 18:41:44 +0200

John,

So you want your dummy to be 1 whenever "mother_id" is not missing, right? Provided "mother_id" is a numeric variable, the following does the trick

gen dummy = (mother_id < .)

Should mother_id be a string variable, the following syntax should work

gen dummy = (mother_id != "")

Best

Christoph Engel



Am 7/15/2012 6:31 PM, schrieb john.guzek@lshtm.ac.uk:
Hi,


Sorry, this is getting somewhat embarrassing. Apparently the legible
table is not in this chain, so I'll add it again.


idhouse  |idno     |mother_id |x
1           |73664  |.               |1
1           |73665  |.               |.
1           |73666  |.               |.
1           |73667  |73664       |.
1           |73668  |.               |.
2           |94038  |.               |.
2           |94039  |.               |1
2           |94040  |.               |.
2           |94041  |.               |1
2           |94042  |.               |.
2           |94043  |.               |1
2           |94044  |94041       |.
2           |94045  |94039       |.
2           |94046  |.               |1
2           |94047  |94046       |.
2           |94048  |94046       |.
2           |94049  |.               |.
2           |94050  |.               |.
2           |94051  |94043       |.
2           |94052  |.               |.


John
  15/07/12 5:30 PM>>>
Hi,


Sorry, I've not explained this very well. Hopefully the legible version
of the table will help, which I resent. So yes, "y" represents "idno",
"z" represents "mother_id". I'm trying to make "x" to identify the
mothers in "idno". So x=1 if "y" is found anywhere in "z".


Thanks for you help.
John


Christoph Engel  15/07/12 5:18 PM>>>
John,

It still is not fully clear to me what you want. I take it what you
previously called "y" is variable "idno". You actually want a dummy that

is 1 if "idno" is in a certain range, and 0 otherwise. If that is what
you are after, you can use

gen dummy = (idno>  173664&  idno<  294053)

Actually for that purpose it is better that your variable idno is
numeric.

Hope that helps

Christoph Engel




Am 7/15/2012 5:52 PM, schrieb john.guzek@lshtm.ac.uk:
Hi,


Thanks for your help. It's a bit more tricky than that, at least as
far
as I can tell. I'll try and explain a little more clearly! So, as
below,
I have household level and individual level identifiers. I essentially
want to flag the mother's idno. So something along the lines of gen
x=1
if idno=="any value in mother_id" to look like column x below. Whether
column x read 1 or the corresponding idno is not important at this
stage. And I agree, these probably should be stored as string, it's
not
my data!


idhouseidnomother_idx
1736641
173665
173666
17366773664
173668
294038
2940391
294040
2940411
294042
2940431
29404494041
29404594039
2940461
29404794046
29404894046
294049
294050
29405194043
294052



Thanks for your help!
John



Christoph Engel  15/07/12 4:21 PM>>>
John,

You will have to define the value of x if y does not fulfil your
condition, i.e. if it is not equal to z. Depending on your purposes
you
might either want it to be a missing value, or some expression of x,
say
0. I would therefore start out

gen x = .
replace x = y if y == z

(note the "==" in the if clause)

Best

Christoph Engel

Am 7/15/2012 4:59 PM, schrieb Steve Nakoneshny:
John,

At first glance, it would seem that -gen x = y if y = z- would serve
as a solution. Of course, this assumes that your I'd vars are
numerical
and not string vars (which they probably should be stored as).
Steve

Sent via carrier pigeon

On 2012-07-15, at 8:52 AM, "john.guzek@lshtm.ac.uk"  wrote:

Hello,


This is my first time using statalist, I hope I do this all
correctly!
I'm looking to create a variable x which is equal to y, but only if
the given value for y can be found in another variable, z. These are
all
id numbers, so say y is a universal id and z is a mother's id, telling
you the universal id of the mother in relation to the child.
For example:


yzx


1..
2.2
3.3
42.
5..
6..
737
8..
9..
107.


So I'm trying to figure out how to create x. Any help would be much
appreciated.
Thanks,
John


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--
_________________________________________________________________
Prof. Dr. Christoph Engel
Max-Planck-Institut zur
Erforschung von Gemeinschaftsgütern
Max Planck Institute for Research on Collective Goods
Kurt-Schumacher-Strasse 10
D 53113 Bonn
Tel. +49/228/91416-10
Fax +49/228/91416-11
e-mail:engel@coll.mpg.de
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_________________________________________________________________

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