[metslib] Problem with random_shuffle

[Mirko Maischberger]

Hello,
can you please try if the following random_shuffle function fixes the
problem you are experiencing?

Please feel free to ask any question about migrating from 0.4 to 0.5 (or to
fill the wiki page on migration, that is just a stub right now).


Thank you and happy coding!
Mirko

  template<typename random_generator>
  void random_shuffle(permutation_problem& p, random_generator& rng)
  {
#if defined (METSLIB_HAVE_UNORDERED_MAP) && !defined
(METSLIB_TR1_MIXED_NAMESPACE)
    std::uniform_int<size_t> unigen;
    std::variate_generator<random_generator&,
      std::uniform_int<size_t> >gen(rng, unigen);
#else
    std::tr1::uniform_int<size_t> unigen;
    std::tr1::variate_generator<random_generator&,
      std::tr1::uniform_int<size_t> >gen(rng, unigen);
#endif
    std::random_shuffle(p.pi_m.begin(), p.pi_m.end(), gen);
    p.update_cost();
  }


On Wed, Nov 10, 2010 at 3:35 AM, Mirko Maischberger <
mirko.maischberger at gmail.com> wrote:

> Hello,
>
> Thank you for debugging and for having tracked the error down.
>
> I'm aware of some compatibility issues/bugs in the tr1/random libraries. I
> will look into the problem in the next few days and I hope to release a fix
> real soon.
>
> Mirko
>
>
> On Tue, Nov 9, 2010 at 1:01 AM, Shahin Gelareh <shahin.gelareh at gmail.com>wrote:
>
>> Hi everybody,
>>
>> It seems like there have been a lot of changes from 4.3 to 5. Thanks for
>> the efforts.
>> The code I had in 4.3 does not work anymore with 5, it is of course
>> migratable but now the main concern is regarding the suffleing algorithm of
>> STL.
>> The results in windows and using MSVC (MSVS2010)compiler is not what one
>> expects. This is for example the case for qap example.
>> I personally cannot run it. It reports exception and exits.
>>
>> One only needs to trace the code until:
>>  template<typename random_generator>
>>   void random_shuffle(permutation_problem& p, random_generator& rng)
>>   {
>> #if defined (METSLIB_HAVE_UNORDERED_MAP) && !defined
>> (METSLIB_TR1_MIXED_NAMESPACE)
>>     std::uniform_int<> unigen(0, p.pi_m.size());
>>     std::variate_generator<random_generator,
>>       std::uniform_int<> >gen(rng, unigen);
>> #else
>>     std::tr1::uniform_int<> unigen(0, p.pi_m.size());
>>     std::tr1::variate_generator<random_generator,
>>       std::tr1::uniform_int<> >gen(rng, unigen);
>> #endif
>>     std::random_shuffle(p.pi_m.begin(), p.pi_m.end(), gen);
>>     p.update_cost();
>>   }
>>
>>
>> The output of this "std::random_shuffle(p.pi_m.begin(), p.pi_m.end(),
>> gen);" is the original permutation where some of the cells are swapped BUT
>> there are some strange numbers among the numbers. large positive values
>> specifically. I searched a lot with no success about how to overcome.
>>
>> I was wondering if anyone has any idea?
>>
>>
>> _______________________________________________
>> metslib mailing list
>> metslib at list.coin-or.org
>> http://list.coin-or.org/mailman/listinfo/metslib
>>
>
>
>
> --
> Mirko Maischberger
> @ | mirko.maischberger at gmail.com
>



-- 
Mirko Maischberger
@ | mirko.maischberger at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://list.coin-or.org/pipermail/metslib/attachments/20101112/1d78ab8b/attachment.html