boost random

[Gary Wessle]

Hi

using The Boost Random Number Library. how can I get a random number
every time I run the project "./proj"

the code below prints out 10 random numbers but it will print the same
exact numbers every time it runs. I just need one number not 10, and
random "different from the one before".
I can do the first "remove the for loop" but not able to do the
second.

#include <boost/random.hpp>
typedef boost::minstd_rand base_generator_type;
int main(){
base_generator_type generator(42u);
boost::uniform_real<uni_dist(0,1);
boost::variate_generator<base_generator_type&, boost::uniform_real< uni(generator, uni_dist);
for(int i=0; i<10; i++)
std::cout << uni() << std::endl;
}

thanks

[Klaas Vantournhout]

I don't know much about the boost library, but is it not possible to
give a seed number. If it is then you can make your seed number
depending on the time when the program starts to run.

Klaas

Gary Wessle wrote:

Hi

using The Boost Random Number Library. how can I get a random number
every time I run the project "./proj"

the code below prints out 10 random numbers but it will print the same
exact numbers every time it runs. I just need one number not 10, and
random "different from the one before".
I can do the first "remove the for loop" but not able to do the
second.

#include <boost/random.hpp>
typedef boost::minstd_rand base_generator_type;
int main(){
base_generator_type generator(42u);
boost::uniform_real<uni_dist(0,1);
boost::variate_generator<base_generator_type&, boost::uniform_real< uni(generator, uni_dist);
for(int i=0; i<10; i++)
std::cout << uni() << std::endl;
}

thanks

[Markus Moll]

Hi

Klaas Vantournhout wrote:

I don't know much about the boost library, but is it not possible to
give a seed number. If it is then you can make your seed number
depending on the time when the program starts to run.

Of course it is:

Gary Wessle wrote:

> base_generator_type generator(42u);

And while 42 is the answer to basically everything, it is not a good seed.
( e.g. clock() might be much better, on UNIces, reading from /dev/random
would provide a good seed )

Markus