commit cdec5b6fce4cef8daf7d1de3f76493266d7c8693
parent ff3685766b18c89ffb753de753e16ed38693c31b
Author: NunoSempere <nuno.sempere@protonmail.com>
Date: Fri, 2 Jun 2023 16:05:42 -0600
remove old code from samples.c
Diffstat:
| M | C/samples.c | | | 171 | ++++++++++++++++++++++++++----------------------------------------------------- |
1 file changed, 56 insertions(+), 115 deletions(-)
diff --git a/C/samples.c b/C/samples.c
@@ -18,18 +18,6 @@ void array_print(float* array, int length)
printf("\n");
}
-void array_fill(float* array, int length, float item)
-{
- int i;
- #pragma omp private(i)
- {
- #pragma omp for
- for (i = 0; i < length; i++) {
- array[i] = item;
- }
- }
-}
-
float array_sum(float* array, int length)
{
float output = 0.0;
@@ -47,10 +35,57 @@ void array_cumsum(float* array_to_sum, float* array_cumsummed, int length)
}
}
+// Split array helpers
+int split_array_get_my_length(int index, int total_length, int n_threads)
+{
+ return (total_length % n_threads > index ? total_length / n_threads + 1 : total_length / n_threads);
+}
+
+void split_array_allocate(float** meta_array, int length, int divide_into)
+{
+ int own_length;
+
+ for (int i = 0; i < divide_into; i++) {
+ own_length = split_array_get_my_length(i, length, divide_into);
+ meta_array[i] = malloc(own_length * sizeof(float));
+ }
+}
+
+void split_array_free(float** meta_array, int divided_into)
+{
+ for (int i = 0; i < divided_into; i++) {
+ free(meta_array[i]);
+ }
+ free(meta_array);
+}
+
+float split_array_sum(float** meta_array, int length, int divided_into)
+{
+ int i;
+ float output;
+ float* partial_sum = malloc(divided_into * sizeof(float));
+
+ #pragma omp private(i) shared(partial_sum)
+ for (int i = 0; i < divided_into; i++) {
+ float own_partial_sum = 0;
+ int own_length = split_array_get_my_length(i, length, divided_into);
+ for (int j = 0; j < own_length; j++) {
+ own_partial_sum += meta_array[i][j];
+ }
+ partial_sum[i] = own_partial_sum;
+ }
+ for (int i = 0; i < divided_into; i++) {
+ output += partial_sum[i];
+ }
+ return output;
+}
+
+// Distribution & sampling functions
+
float rand_float(float to, unsigned int* 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>
+ // 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.
}
@@ -87,58 +122,11 @@ inline float random_to(float low, float high, unsigned int* seed)
return random_lognormal(logmean, logsigma, seed);
}
-int split_array_get_my_length(int index, int total_length, int n_threads)
-{
- return (total_length % n_threads > index ? total_length / n_threads + 1 : total_length / n_threads);
-}
-
-//Old version, don't use it!! Optimized version is called mixture_f. This one is just for display
-/*
-void mixture(float* dists[], float* weights, int n_dists, float* results)
-{
- float sum_weights = array_sum(weights, n_dists);
- float* normalized_weights = malloc(n_dists * sizeof(float));
- for (int i = 0; i < n_dists; i++) {
- normalized_weights[i] = weights[i] / sum_weights;
- }
-
- float* cummulative_weights = malloc(n_dists * sizeof(float));
- array_cumsum(normalized_weights, cummulative_weights, n_dists);
-
- //create var holders
- float p1, p2;
- int index_found, index_counter, sample_index, i;
-
- #pragma omp parallel private(i, p1, p2, index_found, index_counter, sample_index)
- {
- #pragma omp for
- for (i = 0; i < N; i++) {
- p1 = random_uniform(0, 1);
- p2 = random_uniform(0, 1);
-
- index_found = 0;
- index_counter = 0;
-
- while ((index_found == 0) && (index_counter < n_dists)) {
- if (p1 < cummulative_weights[index_counter]) {
- index_found = 1;
- } else {
- index_counter++;
- }
- }
- if (index_found != 0) {
- sample_index = (int)(p2 * N);
- results[i] = dists[index_counter][sample_index];
- } else
- printf("This shouldn't be able to happen.\n");
- }
- }
- free(normalized_weights);
- free(cummulative_weights);
-}
-*/
-void mixture_f(float (*samplers[])(unsigned int* ), float* weights, int n_dists, float** results, int n_threads)
+// Mixture function
+void mixture(float (*samplers[])(unsigned int* ), float* weights, int n_dists, float** results, int n_threads)
{
+ // You can see a simpler version of this function in the git history
+ // or in C-02-better-algorithm-one-thread/
float sum_weights = array_sum(weights, n_dists);
float* normalized_weights = malloc(n_dists * sizeof(float));
for (int i = 0; i < n_dists; i++) {
@@ -180,6 +168,9 @@ void mixture_f(float (*samplers[])(unsigned int* ), float* weights, int n_dists,
}
}
+// Functions used for the BOTEC.
+// Their type has to be the same, as we will be passing them around.
+
float sample_0(unsigned int* seed)
{
return 0;
@@ -200,53 +191,9 @@ float sample_many(unsigned int* seed)
return random_to(2, 10, seed);
}
-void split_array_allocate(float** meta_array, int length, int divide_into)
-{
- int own_length;
-
- for (int i = 0; i < divide_into; i++) {
- own_length = split_array_get_my_length(i, length, divide_into);
- meta_array[i] = malloc(own_length * sizeof(float));
- }
-}
-
-void split_array_free(float** meta_array, int divided_into)
-{
- for (int i = 0; i < divided_into; i++) {
- free(meta_array[i]);
- }
- free(meta_array);
-}
-
-float split_array_sum(float** meta_array, int length, int divided_into)
-{
- int i;
- float output;
- float* partial_sum = malloc(divided_into * sizeof(float));
-
- #pragma omp private(i) shared(partial_sum)
- for (int i = 0; i < divided_into; i++) {
- float own_partial_sum = 0;
- int own_length = split_array_get_my_length(i, length, divided_into);
- for (int j = 0; j < own_length; j++) {
- own_partial_sum += meta_array[i][j];
- }
- partial_sum[i] = own_partial_sum;
- }
- for (int i = 0; i < divided_into; i++) {
- output += partial_sum[i];
- }
- return output;
-}
-
int main()
{
- //initialize randomness
- srand(time(NULL));
- // clock_t start, end;
- // start = clock();
-
// Toy example
// Declare variables in play
float p_a, p_b, p_c;
@@ -266,16 +213,10 @@ int main()
float weights[] = { 1 - p_c, p_c / 2, p_c / 4, p_c / 4 };
float (*samplers[])(unsigned int* ) = { sample_0, sample_1, sample_few, sample_many };
- mixture_f(samplers, weights, n_dists, dist_mixture, n_threads);
+ mixture(samplers, weights, n_dists, dist_mixture, n_threads);
printf("Sum(dist_mixture, N)/N = %f\n", split_array_sum(dist_mixture, N, n_threads) / N);
// array_print(dist_mixture[0], N);
split_array_free(dist_mixture, n_threads);
- // end = clock();
- // printf("Time (ms): %f\n", ((double)(end - start)) / (CLOCKS_PER_SEC) * 1000);
- // ^ Will only measure how long it takes the inner main to run, not the whole program,
- // including e.g., loading the program into memory or smth.
- // Also CLOCKS_PER_SEC in POSIX is a constant equal to 1000000.
- // See: https://stackoverflow.com/questions/10455905/why-is-clocks-per-sec-not-the-actual-number-of-clocks-per-second
return 0;
}
