more refactoring

1 files changed, 20 insertions, 0 deletions

diff --git a/src/rand.c b/src/rand.c
new file mode 100644
index 0000000..1a6a3d4
--- /dev/null
+++ b/src/rand.c
@@ -0,0 +1,20 @@
+
+#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;
+}
+
+double rand_dist_pow(const gsl_rng *r, double beta) {
+	double x = 0;
+
+	// underflow means that for very small beta x is sometimes identically zero,
+	// which causes problems
+	while ((x = exp(log(gsl_rng_uniform_pos(r)) / beta)) == 0.0);
+
+	return x;
+}