Re: [Help-gsl] how to seed qrng generators?

[Joakim Hove]

Kevin Thornton <address@hidden> writes:


>   gsl_rng_env_setup();
>   T = gsl_rng_default;
>   r = gsl_rng_alloc (T);

Right here you put in a call:

    gsl_rng_set(r , seed);

If you do not call this routine explicitly the generator is seeded
wtih a default seed. To actually get a seed you can (at linux at
least) use /dev/random:


  unsigned int seed;
  FILE *dev_random;

  dev_random = fopen("/dev/random","r");
  if (dev_random == NULL) {
    fprintf(stderr,"Can not open /dev/random - seeding failed\n");
    seed = 0;
  } else {
    fread(&seed , sizeof(seed), 1, dev_random);
    fclose(dev_random);
  }



This code (or something very close) has been posted here before;
i.e. I am not the true author of this.

HTH - Joakim

 


-- 
Joakim Hove
hove AT ift uib no                 /    
Tlf: +47 (55 5)8 27 90            /     Stabburveien 18          
Fax: +47 (55 5)8 94 40           /      N-5231 Paradis           
http://www.ift.uib.no/~hove/    /       55 91 28 18 / 92 68 57 04