commit fa832cbd17733abc6e760572b46a27d580b9df24
parent 279fb12dee25956fa6b9b4924131c11c235e868e
Author: NunoSempere <nuno.sempere@protonmail.com>
Date: Mon, 29 Jan 2024 18:29:17 +0100
use new pattern to reduce nested functions extension
Diffstat:
5 files changed, 118 insertions(+), 135 deletions(-)
diff --git a/examples/core/01_one_sample/example.c b/examples/core/01_one_sample/example.c
@@ -4,12 +4,12 @@
// Estimate functions
-double sample_model(uint64_t* seed){
+double sample_0(uint64_t* seed) { UNUSED(seed); return 0; }
+double sample_1(uint64_t* seed) { UNUSED(seed); return 1; }
+double sample_few(uint64_t* seed) { return sample_to(1, 3, seed); }
+double sample_many(uint64_t* seed) { return sample_to(2, 10, seed); }
- double sample_0(uint64_t* seed) { UNUSED(seed); return 0; }
- double sample_1(uint64_t* seed) { UNUSED(seed); return 1; }
- double sample_few(uint64_t* seed) { return sample_to(1, 3, seed); }
- double sample_many(uint64_t* seed) { return sample_to(2, 10, seed); }
+double sample_model(uint64_t* seed){
double p_a = 0.8;
double p_b = 0.5;
diff --git a/examples/core/02_time_to_botec/example.c b/examples/core/02_time_to_botec/example.c
@@ -2,37 +2,35 @@
#include <stdio.h>
#include <stdlib.h>
-int main()
-{
- // set randomness seed
- uint64_t* seed = malloc(sizeof(uint64_t));
- *seed = 1000; // xorshift can't start with 0
+double sample_0(uint64_t* seed) { UNUSED(seed); return 0; }
+double sample_1(uint64_t* seed) { UNUSED(seed); return 1; }
+double sample_few(uint64_t* seed) { return sample_to(1, 3, seed); }
+double sample_many(uint64_t* seed) { return sample_to(2, 10, seed); }
+
+double sample_model(uint64_t* seed){
double p_a = 0.8;
double p_b = 0.5;
double p_c = p_a * p_b;
- double sample_0(uint64_t * seed)
- {
- UNUSED(seed);
- return 0;
- }
- double sample_1(uint64_t * seed)
- {
- UNUSED(seed);
- return 1;
- }
- double sample_few(uint64_t * seed) { return sample_to(1, 3, seed); }
- double sample_many(uint64_t * seed) { return sample_to(2, 10, seed); }
-
int n_dists = 4;
double weights[] = { 1 - p_c, p_c / 2, p_c / 4, p_c / 4 };
double (*samplers[])(uint64_t*) = { sample_0, sample_1, sample_few, sample_many };
+ double result = sample_mixture(samplers, weights, n_dists, seed);
+
+ return result;
+}
+
+int main()
+{
+ // set randomness seed
+ uint64_t* seed = malloc(sizeof(uint64_t));
+ *seed = 1000; // xorshift can't start with 0
int n_samples = 1000000;
double* result_many = (double*)malloc((size_t)n_samples * sizeof(double));
for (int i = 0; i < n_samples; i++) {
- result_many[i] = sample_mixture(samplers, weights, n_dists, seed);
+ result_many[i] = sample_model(seed);
}
printf("Mean: %f\n", array_mean(result_many, n_samples));
diff --git a/examples/core/03_gcc_nested_function/example.c b/examples/core/03_gcc_nested_function/example.c
@@ -2,39 +2,36 @@
#include <stdio.h>
#include <stdlib.h>
-int main()
-{
- // set randomness seed
- uint64_t* seed = malloc(sizeof(uint64_t));
- *seed = 1000; // xorshift can't start with 0
+double sample_model(uint64_t* seed){
+
+ double sample_0(uint64_t* seed) { UNUSED(seed); return 0; }
+ // Using a gcc extension, you can define a function inside another function
+ double sample_1(uint64_t* seed) { UNUSED(seed); return 1; }
+ double sample_few(uint64_t* seed) { return sample_to(1, 3, seed); }
+ double sample_many(uint64_t* seed) { return sample_to(2, 10, seed); }
double p_a = 0.8;
double p_b = 0.5;
double p_c = p_a * p_b;
int n_dists = 4;
+ double weights[] = { 1 - p_c, p_c / 2, p_c / 4, p_c / 4 };
+ double (*samplers[])(uint64_t*) = { sample_0, sample_1, sample_few, sample_many };
+ double result = sample_mixture(samplers, weights, n_dists, seed);
- // These are nested functions. They will not compile without gcc.
- double sample_0(uint64_t * seed)
- {
- UNUSED(seed);
- return 0;
- }
- double sample_1(uint64_t * seed)
- {
- UNUSED(seed);
- return 1;
- }
- double sample_few(uint64_t * seed) { return sample_to(1, 3, seed); }
- double sample_many(uint64_t * seed) { return sample_to(2, 10, seed); }
+ return result;
+}
- double (*samplers[])(uint64_t*) = { sample_0, sample_1, sample_few, sample_many };
- double weights[] = { 1 - p_c, p_c / 2, p_c / 4, p_c / 4 };
+int main()
+{
+ // set randomness seed
+ uint64_t* seed = malloc(sizeof(uint64_t));
+ *seed = 1000; // xorshift can't start with 0
int n_samples = 1000000;
double* result_many = (double*)malloc((size_t)n_samples * sizeof(double));
for (int i = 0; i < n_samples; i++) {
- result_many[i] = sample_mixture(samplers, weights, n_dists, seed);
+ result_many[i] = sample_model(seed);
}
printf("result_many: [");
@@ -42,5 +39,6 @@ int main()
printf("%.2f, ", result_many[i]);
}
printf("]\n");
+
free(seed);
}
diff --git a/examples/core/04_gamma_beta/example.c b/examples/core/04_gamma_beta/example.c
@@ -2,8 +2,6 @@
#include <stdio.h>
#include <stdlib.h>
-// Estimate functions
-
int main()
{
// set randomness seed
@@ -11,33 +9,21 @@ int main()
*seed = 1000; // xorshift can't start with 0
int n = 1000 * 1000;
- /*
- for (int i = 0; i < n; i++) {
- double gamma_0 = sample_gamma(0.0, seed);
- // printf("sample_gamma(0.0): %f\n", gamma_0);
- }
- printf("\n");
- */
-
- double* gamma_1_array = malloc(sizeof(double) * (size_t)n);
+ double* gamma_array = malloc(sizeof(double) * (size_t)n);
for (int i = 0; i < n; i++) {
- double gamma_1 = sample_gamma(1.0, seed);
- // printf("sample_gamma(1.0): %f\n", gamma_1);
- gamma_1_array[i] = gamma_1;
+ gamma_array[i] = sample_gamma(1.0, seed);
}
- printf("gamma(1) summary statistics = mean: %f, std: %f\n", array_mean(gamma_1_array, n), array_std(gamma_1_array, n));
- free(gamma_1_array);
+ printf("gamma(1) summary statistics = mean: %f, std: %f\n", array_mean(gamma_array, n), array_std(gamma_array, n));
printf("\n");
- double* beta_1_2_array = malloc(sizeof(double) * (size_t)n);
+ double* beta_array = malloc(sizeof(double) * (size_t)n);
for (int i = 0; i < n; i++) {
- double beta_1_2 = sample_beta(1, 2.0, seed);
- // printf("sample_beta(1.0, 2.0): %f\n", beta_1_2);
- beta_1_2_array[i] = beta_1_2;
+ beta_array[i] = sample_beta(1, 2.0, seed);
}
- printf("beta(1,2) summary statistics: mean: %f, std: %f\n", array_mean(beta_1_2_array, n), array_std(beta_1_2_array, n));
- free(beta_1_2_array);
+ printf("beta(1,2) summary statistics: mean: %f, std: %f\n", array_mean(beta_array, n), array_std(beta_array, n));
printf("\n");
+ free(gamma_array);
+ free(beta_array);
free(seed);
}
diff --git a/examples/core/06_dissolving_fermi_paradox/example.c b/examples/core/06_dissolving_fermi_paradox/example.c
@@ -4,86 +4,87 @@
#include <stdio.h>
#include <stdlib.h>
-int main()
+double sample_fermi_logspace(uint64_t * seed)
{
// Replicate <https://arxiv.org/pdf/1806.02404.pdf>, and in particular the red line in page 11.
+ // You can see a simple version of this function in naive.c in this same folder
+ double log_rate_of_star_formation = sample_uniform(log(1), log(100), seed);
+ double log_fraction_of_stars_with_planets = sample_uniform(log(0.1), log(1), seed);
+ double log_number_of_habitable_planets_per_star_system = sample_uniform(log(0.1), log(1), seed);
- // set randomness seed
- uint64_t* seed = malloc(sizeof(uint64_t));
- *seed = 1001; // xorshift can't start with a seed of 0
+ double log_rate_of_life_formation_in_habitable_planets = sample_normal(1, 50, seed);
+ double log_fraction_of_habitable_planets_in_which_any_life_appears;
+ /*
+ Consider:
+ a = underlying normal
+ b = rate_of_life_formation_in_habitable_planets = exp(underlying normal) = exp(a)
+ c = 1 - exp(-b) = fraction_of_habitable_planets_in_which_any_life_appears
+ d = log(c)
- double sample_fermi_logspace(uint64_t * seed)
- {
- // You can see a simple version of this function in naive.c in this same folder
- double log_rate_of_star_formation = sample_uniform(log(1), log(100), seed);
- double log_fraction_of_stars_with_planets = sample_uniform(log(0.1), log(1), seed);
- double log_number_of_habitable_planets_per_star_system = sample_uniform(log(0.1), log(1), seed);
+ Looking at the Taylor expansion for c = 1 - exp(-b), it's
+ b - b^2/2 + b^3/6 - x^b/24, etc.
+ <https://www.wolframalpha.com/input?i=1-exp%28-x%29>
+ When b ~ 0 (as is often the case), this is close to b.
- double log_rate_of_life_formation_in_habitable_planets = sample_normal(1, 50, seed);
- double log_fraction_of_habitable_planets_in_which_any_life_appears;
- /*
- Consider:
- a = underlying normal
- b = rate_of_life_formation_in_habitable_planets = exp(underlying normal) = exp(a)
- c = 1 - exp(-b) = fraction_of_habitable_planets_in_which_any_life_appears
- d = log(c)
+ But now, if b ~ 0, c ~ b
+ and d = log(c) ~ log(b) = log(exp(a)) = a
- Looking at the Taylor expansion for c = 1 - exp(-b), it's
- b - b^2/2 + b^3/6 - x^b/24, etc.
- <https://www.wolframalpha.com/input?i=1-exp%28-x%29>
- When b ~ 0 (as is often the case), this is close to b.
+ Now, we could play around with estimating errors,
+ and indeed if we want b^2/2 = exp(a)^2/2 < 10^(-n), i.e., to have n decimal digits of precision,
+ we could compute this as e.g., a < (nlog(10) + log(2))/2
+ so for example if we want ten digits of precision, that's a < -11
+
+ Empirically, the two numbers as calculated in C do become really close around 11 or so,
+ and at 38 that calculation results in a -inf (so probably a floating point error or similar.)
+ So we should be using that formula for somewhere between -38 << a < -11
- But now, if b ~ 0, c ~ b
- and d = log(c) ~ log(b) = log(exp(a)) = a
+ I chose -16 as a happy medium after playing around with
+ double invert(double x){
+ return log(1-exp(-exp(-x)));
+ }
+ for(int i=0; i<64; i++){
+ double j = i;
+ printf("for %lf, log(1-exp(-exp(-x))) is calculated as... %lf\n", j, invert(j));
+ }
+ and <https://www.wolframalpha.com/input?i=log%281-exp%28-exp%28-16%29%29%29>
+ */
+ if (log_rate_of_life_formation_in_habitable_planets < -16) {
+ log_fraction_of_habitable_planets_in_which_any_life_appears = log_rate_of_life_formation_in_habitable_planets;
+ } else {
+ double rate_of_life_formation_in_habitable_planets = exp(log_rate_of_life_formation_in_habitable_planets);
+ double fraction_of_habitable_planets_in_which_any_life_appears = -expm1(-rate_of_life_formation_in_habitable_planets);
+ log_fraction_of_habitable_planets_in_which_any_life_appears = log(fraction_of_habitable_planets_in_which_any_life_appears);
+ }
- Now, we could play around with estimating errors,
- and indeed if we want b^2/2 = exp(a)^2/2 < 10^(-n), i.e., to have n decimal digits of precision,
- we could compute this as e.g., a < (nlog(10) + log(2))/2
- so for example if we want ten digits of precision, that's a < -11
-
- Empirically, the two numbers as calculated in C do become really close around 11 or so,
- and at 38 that calculation results in a -inf (so probably a floating point error or similar.)
- So we should be using that formula for somewhere between -38 << a < -11
+ double log_fraction_of_planets_with_life_in_which_intelligent_life_appears = sample_uniform(log(0.001), log(1), seed);
+ double log_fraction_of_intelligent_planets_which_are_detectable_as_such = sample_uniform(log(0.01), log(1), seed);
+ double log_longevity_of_detectable_civilizations = sample_uniform(log(100), log(10000000000), seed);
- I chose -16 as a happy medium after playing around with
- double invert(double x){
- return log(1-exp(-exp(-x)));
- }
- for(int i=0; i<64; i++){
- double j = i;
- printf("for %lf, log(1-exp(-exp(-x))) is calculated as... %lf\n", j, invert(j));
- }
- and <https://www.wolframalpha.com/input?i=log%281-exp%28-exp%28-16%29%29%29>
- */
- if (log_rate_of_life_formation_in_habitable_planets < -16) {
- log_fraction_of_habitable_planets_in_which_any_life_appears = log_rate_of_life_formation_in_habitable_planets;
- } else {
- double rate_of_life_formation_in_habitable_planets = exp(log_rate_of_life_formation_in_habitable_planets);
- double fraction_of_habitable_planets_in_which_any_life_appears = -expm1(-rate_of_life_formation_in_habitable_planets);
- log_fraction_of_habitable_planets_in_which_any_life_appears = log(fraction_of_habitable_planets_in_which_any_life_appears);
- }
+ double log_n =
+ log_rate_of_star_formation +
+ log_fraction_of_stars_with_planets +
+ log_number_of_habitable_planets_per_star_system +
+ log_fraction_of_habitable_planets_in_which_any_life_appears +
+ log_fraction_of_planets_with_life_in_which_intelligent_life_appears +
+ log_fraction_of_intelligent_planets_which_are_detectable_as_such +
+ log_longevity_of_detectable_civilizations;
+ return log_n;
+}
- double log_fraction_of_planets_with_life_in_which_intelligent_life_appears = sample_uniform(log(0.001), log(1), seed);
- double log_fraction_of_intelligent_planets_which_are_detectable_as_such = sample_uniform(log(0.01), log(1), seed);
- double log_longevity_of_detectable_civilizations = sample_uniform(log(100), log(10000000000), seed);
+double sample_are_we_alone_logspace(uint64_t * seed)
+{
+ double log_n = sample_fermi_logspace(seed);
+ return ((log_n > 0) ? 1 : 0);
+ // log_n > 0 => n > 1
+}
- double log_n =
- log_rate_of_star_formation +
- log_fraction_of_stars_with_planets +
- log_number_of_habitable_planets_per_star_system +
- log_fraction_of_habitable_planets_in_which_any_life_appears +
- log_fraction_of_planets_with_life_in_which_intelligent_life_appears +
- log_fraction_of_intelligent_planets_which_are_detectable_as_such +
- log_longevity_of_detectable_civilizations;
- return log_n;
- }
- double sample_are_we_alone_logspace(uint64_t * seed)
- {
- double log_n = sample_fermi_logspace(seed);
- return ((log_n > 0) ? 1 : 0);
- // log_n > 0 => n > 1
- }
+int main()
+{
+
+ // set randomness seed
+ uint64_t* seed = malloc(sizeof(uint64_t));
+ *seed = 1001; // xorshift can't start with a seed of 0
double logspace_fermi_proportion = 0;
int n_samples = 1000 * 1000;
