Re: help with mersenne_twister

From: agiatojon (JonAgiato_at_[hidden])
Date: 2003-03-17 14:23:59

--- In Boost-Users_at_[hidden], scleary_at_j... wrote:
> > -----Original Message-----
> > From: Jon Agiato [mailto:JonAgiato_at_n...]
> > 
> > I am having difficulty in understanding the documentation 
regarding 
> > the use of the pseudo-random number generators in 
boost::random.  
> > Below, I have created a small sample program of the type I am 
trying 
> > to create in order to use the various classes in boost::random 
with 
> > Diehard (requires a binary file of 32 bit integers for 
testing).  
> > This program does not compile as it says that mersenne_twister 
> > requires template arguments.  I understand what that means of 
> > course, but am unsure as to what arguments should go in there.  
I am 
> > using MSVC++ 7.0 and would really apprechiate any assistance.  
> > Thanks!
> 
> The Boost.Random library defines fully-generic random number 
generator
> algorithms, e.g., boost::random::mersenne_twister,
> boost::random::linear_congruential, etc.  These are only for 
advanced users.

Hello Steve, and thank you for your kind help.  I am trying to use 
the boost library as part of a project in which I demonstrate the 
validity of various random number generation algorithms and 
methodologies.  I wanted to use boost to demonstrate what can be 
achieved through top class C++ generic programming.
> 
> The Boost.Random library also provides specializations of those 
generic
> random number generator algorithms for use by normal users.  e.g.,
> boost::mt19937 and boost::mt11213b are both specializations of the 
Mersenne
> twister; and boost::minstd_rand is a specialization of the linear
> congruential algorithm.
> 
> So, unless you have really exceptional random number requirements, 
you
> should be using boost::mt19937 instead of 
boost::random::mersenne_twister:

I used mt19937 as you directed and my example did compile but when I 
ran the binary file through Diehard it failed every single test 
every time.  I am sure this can not be due to the algorithm, but I 
can not pinpoint what I could be doing in error.  Here is the code I 
used to create a binary file for diehard:

#include <iostream>
using std::cout;
using std::cin;

#include <cstdlib>

#include <boost/random/mersenne_twister.hpp>
using boost::mt19937;

#include <iomanip>
using std::ios;

#include <fstream>
using std::ofstream;

int main()
{
        ofstream file("MTRNG.bin", ios::binary);
        const unsigned int N = 30000;
        unsigned int i = 0;
        mt19937 MT;
        for(; i != N; ++i)
        {
                file << MT;
        }

        cout << "Operation complete.  Press enter to exit...";
        cin.get();

        return EXIT_SUCCESS;
}
> 
> > using boost::random::mersenne_twister;
> 
> using boost::mt19937;
> 
> >       mersenne_twister MT;
> 
> mt19937 MT;
> 
> Then your example should compile.
> 	-Steve

I was intending on using boost::random to demonstrate various 
deterministic and non-deterministic RNGs and their validity as far 
as randomness using Diehard.  I am thinking either I am doing 
something wrong, or maybe I do require the use of the advanced RNG 
classes boost offers.  Does anyone have any ideas?

Again, thanks for any and all assistance.

Jon Agiato
JonAgiato_at_[hidden]