squiggle.c/test/test.c

#include "../squiggle.h"
#include <stdint.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>

#define N  1000 * 1000
#define PERCENTAGE_TOLERANCE 1.0/1000.0

void test_unit_uniform(uint64_t* seed){
	double* unit_uniform_array = malloc(sizeof(double) * N);
	
	for(int i=0; i<N; i++){
		unit_uniform_array[i] = sample_unit_uniform(seed);
	}
	
	double mean = array_mean(unit_uniform_array, N);
	double expected_mean = 0.5;
	double delta_mean = mean - expected_mean;

	double std = array_std(unit_uniform_array, N);
	double expected_std = sqrt(1.0/12.0);
	double delta_std = std - expected_std;
	
	printf("Mean of unit uniform: %f, vs expected mean: %f, delta: %f\n", mean, expected_mean, delta_mean);
	printf("Std of unit uniform: %f, vs expected std: %f, delta: %f\n", std, expected_std, delta_std);

	if(fabs(delta_mean) > PERCENTAGE_TOLERANCE){
		printf("[-] Mean test for unit uniform NOT passed.\n");
	}else {
		printf("[x] Mean test for unit uniform PASSED\n");
	}

	if(fabs(delta_std) > PERCENTAGE_TOLERANCE){
		printf("[-] Std test for unit uniform NOT passed.\n");
	}else {
		printf("[x] Std test for unit uniform PASSED\n");
	}
	
	printf("\n");

}

void test_uniform(double start, double end, uint64_t* seed){
	double* uniform_array = malloc(sizeof(double) * N);
	
	for(int i=0; i<N; i++){
		uniform_array[i] = sample_uniform(start, end, seed);
	}
	
	double mean = array_mean(uniform_array, N);
	double expected_mean = (start + end) / 2; 
	double delta_mean = mean - expected_mean;
	
	double std = array_std(uniform_array, N);
	double expected_std = sqrt(1.0/12.0) * fabs(end-start);
	double delta_std = std - expected_std;
	
	double width = fabs(end - start);
	if(fabs(delta_mean) > width * PERCENTAGE_TOLERANCE){
		printf("[-] Mean test for [%.1f, %.1f] uniform NOT passed.\n", start, end);
		printf("Mean of [%.1f, %.1f] uniform: %f, vs expected mean: %f, delta: %f\n", start, end, mean, expected_mean, mean - expected_mean);
	}else {
		printf("[x] Mean test for [%.1f, %.1f] uniform PASSED\n", start, end);
	}

	if(fabs(delta_std) > width * PERCENTAGE_TOLERANCE){
		printf("[-] Std test for [%.1f, %.1f] uniform NOT passed.\n", start, end);
		printf("Std of [%.1f, %.1f] uniform: %f, vs expected std: %f, delta: %f\n", start, end, std, expected_std, std - expected_std);
		for(int i=0; i<10; i++){

			printf("%.1f, ", uniform_array[i]);
		}
	}else {
		printf("[x] Std test for [%.1f, %.1f] uniform PASSED\n", start, end);
	}
	printf("\n");

}

int main(){
    // set randomness seed
    uint64_t* seed = malloc(sizeof(uint64_t));
    *seed = 1000; // xorshift can't start with a seed of 0
   
		printf("Testing unit uniform\n");
		test_unit_uniform(seed);

		printf("Testing small uniforms\n");
		for(int i=0; i<100; i++){
			double start = sample_uniform(-10, 10, seed);
			double end = sample_uniform(-10, 10, seed);
			if ( end > start){
				test_uniform(start, end, seed);
			}
		}

		printf("Testing wide uniforms\n");
		for(int i=0; i<100; i++){
			double start = sample_uniform(-1000 * 1000, 1000 * 1000, seed);
			double end = sample_uniform(-1000 * 1000, 1000 * 1000, seed);
			if ( end > start){
				test_uniform(start, end, seed);
			}
		}

		free(seed);
}