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RE: st: Creating choice indicator!


From   Nick Cox <n.j.cox@durham.ac.uk>
To   "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu>
Subject   RE: st: Creating choice indicator!
Date   Tue, 20 Mar 2012 18:24:08 +0000

Alternatively, look upwards! 

ceil(5 * runiform()) 

Nick 
n.j.cox@durham.ac.uk 

Scott Merryman

For a random integer between 1 and 5 the code should be :

 1 + floor(5*runiform())

On Tue, Mar 20, 2012 at 12:32 PM, Peter Grand <grand@ihs.ac.at> wrote:
> @ Scott: Exactly, thank you very much!
>
> @ Joerg: Sorry, if I have not been able to correctly specify my request.
>
> Again, thank you for your efforts!
>
Scott Merryman [scott.merryman@gmail.com]

> Something like this?
>
>
> clear
> set obs 5
> gen id = _n
> expand 5
> sort id
>
> bys id: gen order = _n
> gen chosen = 0
> levelsof id, local(levels)
> foreach l of local levels {
>        if runiform() < .5 {  //probability that id is chosen
>        local a = round(1 +4*runiform(),1)
>        qui replace chosen= 1 if order ==  `a' & id == `l' //1 of 5
> alternatives is chosen
>
>        }
> }
> drop order
> l


On Tue, Mar 20, 2012 at 11:51 AM, Peter Grand <grand@ihs.ac.at> wrote:

>> How can I create a random binary variable which indicates either only one chosen alternative or none of them within an id variable, e.g. 5 choices for each individual id :
>>
>>
>> id   chosen
>> 1       0
>> 1       0
>> 1       1
>> 1       0
>> 1       0
>> 2       0
>> 2       0
>> 2       0
>> 2       0
>> 2       0
>> 3       0
>> 3       1
>> 3       0
>> 3       0
>> 3       0
>>

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