src/rand.c


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#include "fracture.h"

unsigned long int rand_seed() {
	FILE *f = fopen("/dev/urandom", "r");
	unsigned long int seed;
	fread(&seed, sizeof(unsigned long int), 1, f);
	fclose(f);
	return seed;
}

long double rand_dist_pow(const gsl_rng *r, double beta) {
	long double x = 0;

	// underflow means that for very small beta x is sometimes identically zero,
	// which causes problems
	while (x == 0.0) {
		long double y = logl(gsl_rng_uniform_pos(r)) / beta;
		x = expl(y);
	}

	return x;
}