commit eaee16f205a3528768276bf94f8b902eb6d6f5ea
parent 80f98830da730e3f99a8ef24b8e1e5e5abbb849d
Author: NunoSempere <nuno.sempere@protonmail.com>
Date: Sat, 3 Jun 2023 04:08:23 -0600
finish integrating xorshift rng
Diffstat:
2 files changed, 18 insertions(+), 15 deletions(-)
diff --git a/C/out/samples b/C/out/samples
Binary files differ.
diff --git a/C/samples.c b/C/samples.c
@@ -79,40 +79,43 @@ float split_array_sum(float** meta_array, int length, int divided_into)
// Pseudo Random number generator
-uint32_t xorshift32(uint32_t* state)
+uint32_t xorshift32(uint32_t* seed)
{
/* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */
- uint32_t x = *state;
+ uint32_t x = *seed;
x ^= x << 13;
x ^= x >> 17;
x ^= x << 5;
- return *state = x;
-}
-
-inline float rand_xorshift32(uint32_t* state){
- return (float) xorshift32(state) / UINT32_MAX;
+ return *seed = x;
}
// Distribution & sampling functions
-float rand_float(float to, uint32_t* seed)
+float rand_0_to_1(uint32_t* seed){
+ return ((float) xorshift32(seed)) / ((float) UINT32_MAX);
+ // previously:
+ // ((float)rand_r(seed) / (float)RAND_MAX)
+ // and before that: rand, but it wasn't thread-safe.
+ // See: <https://stackoverflow.com/questions/43151361/how-to-create-thread-safe-random-number-generator-in-c-using-rand-r> for why to use rand_r:
+ // rand() is not thread-safe, as it relies on (shared) hidden seed.
+}
+
+float rand_float(float max, uint32_t* seed)
{
- return ((float)rand_r(seed) / (float)RAND_MAX) * to;
- // See: <https://stackoverflow.com/questions/43151361/how-to-create-thread-safe-random-number-generator-in-c-using-rand-r> for why to use rand_r:
- // rand() is not thread-safe, as it relies on (shared) hidden state.
+ return rand_0_to_1(seed) * max;
}
float ur_normal(uint32_t* seed)
{
- float u1 = rand_float(1.0, seed);
- float u2 = rand_float(1.0, seed);
+ float u1 = rand_0_to_1(seed);
+ float u2 = rand_0_to_1(seed);
float z = sqrtf(-2.0 * log(u1)) * sin(2 * PI * u2);
return z;
}
float random_uniform(float from, float to, uint32_t* seed)
{
- return ((float)rand_r(seed) / (float)RAND_MAX) * (to - from) + from;
+ return rand_0_to_1(seed) * (to - from) + from;
}
float random_normal(float mean, float sigma, uint32_t* seed)
@@ -155,7 +158,7 @@ void mixture(float (*samplers[])(uint32_t*), float* weights, int n_dists, float*
uint32_t** seeds = malloc(n_threads * sizeof(uint32_t*));
for (uint32_t i = 0; i < n_threads; i++) {
seeds[i] = malloc(sizeof(uint32_t));
- *seeds[i] = i;
+ *seeds[i] = i + 1;
}
#pragma omp parallel private(i, p1, sample_index, split_array_length)
