Re: [Boost-users] Boost random not looking so random

Subject: Re: [Boost-users] Boost random not looking so random
From: Rhys Ulerich (rhys.ulerich_at_[hidden])
Date: 2012-10-28 07:42:01

> > I'm using boost to shuffle an array, but it's not looking as random as I
> > would expect.

> >       for(unsigned i=0;i<5;i++)
> >       {       boost::random::uniform_int_distribution<> dist(min,max);
> >               const int j = dist(rng);
> >               ... code that shuffles stuff using j ...
> >               min++;
> >               cout<<j<<' ';
> >       }
>
> You may of course be using the results of an uniform distribution in a
> way that causes the resulting shuffle have some configurations that are
> more likely than others...

Use std::shuffle from the algorithm header.  This stuff is tricky to get
right if you write it yourself. Google "Knuth shuffle" for some background.

- Rhys