Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Different results with the same code


From   Estrella Gomez <estrellastata@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Different results with the same code
Date   Mon, 10 Feb 2014 10:59:11 +0100

Hi, Nick

I have tried sorting just before the collapse and it happens the same
thing. Does (firstnm) use random values each time then?

Thank you,
Estrella

2014-02-10 10:41 GMT+01:00 Nick Cox <njcoxstata@gmail.com>:
> Contrary to your claim, I would point at this:
>
> Which values are (firstnm) is likely to depend on the exact sort order
> of your data and you are sorting before you -collapse-.
>
> As Phil Schumm often explains, you could get consistent results by
> insisting on stable sorting, but that would be hiding a bug. There's
> evidently some arbitrariness that is better fixed directly.
> Nick
> njcoxstata@gmail.com
>
>
> On 10 February 2014 09:07, Estrella Gomez <estrellastata@gmail.com> wrote:
>> Dear Statalisters
>>
>> I am running a code and I have realized that every time I run it the
>> results (the coefficients and the standard errors) are different. This
>> is the code:
>>
>> clear all
>> use "itunes_grav_song", clear
>> sort id country orig
>>
>> egen  nb_id=tag(id)
>> bysort orig: egen nr_orig=sum(nb_id)
>> bysort orig country: egen nr_dest=sum(available)
>> gen avail_share=(nr_dest/nr_orig)
>> collapse (count) nr_songs=id (firstnm) contig comlang ldist
>> avail_share, by(country orig)
>> encode country, gen(d_id)
>> encode orig, gen(o_id)
>> gen home=country==orig
>>
>> reg avail_share ldist comlang home i.d_id i.o_id
>>
>>
>> I have checked and after the collapse I obtain every time the same
>> dataset, so I don't know what can be the reason
>>
>> Thanks for any help!
>> Estrella
>> *
>> *   For searches and help try:
>> *   http://www.stata.com/help.cgi?search
>> *   http://www.stata.com/support/faqs/resources/statalist-faq/
>> *   http://www.ats.ucla.edu/stat/stata/
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/faqs/resources/statalist-faq/
> *   http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index