start adding some testing

test/makefile

@@ -0,0 +1,53 @@
+# Interface: 
+#   make
+#   make build
+#   make format
+#   make run
+
+# Compiler
+CC=gcc
+# CC=tcc # <= faster compilation
+
+# Main file
+SRC=test.c ../squiggle.c
+OUTPUT=test
+
+## Dependencies
+MATH=-lm
+
+## Flags
+DEBUG= #'-g'
+STANDARD=-std=c99
+WARNINGS=-Wall
+OPTIMIZED=-O3  #-Ofast
+# OPENMP=-fopenmp
+
+## Formatter
+STYLE_BLUEPRINT=webkit
+FORMATTER=clang-format -i -style=$(STYLE_BLUEPRINT)
+
+## make build
+build: $(SRC)
+	$(CC) $(OPTIMIZED) $(DEBUG) $(SRC) $(MATH) -o $(OUTPUT)
+
+format: $(SRC)
+	$(FORMATTER) $(SRC)
+
+run: $(SRC) $(OUTPUT)
+	./$(OUTPUT)
+
+time-linux: 
+	@echo "Requires /bin/time, found on GNU/Linux systems" && echo
+	
+	@echo "Running 100x and taking avg time $(OUTPUT)"
+	@t=$$(/usr/bin/time -f "%e" -p bash -c 'for i in {1..100}; do $(OUTPUT); done' 2>&1 >/dev/null | grep real | awk '{print $$2}' ); echo "scale=2; 1000 * $$t / 100" | bc | sed "s|^|Time using 1 thread: |" | sed 's|$$|ms|' && echo
+
+## Profiling
+
+profile-linux: 
+	echo "Requires perf, which depends on the kernel version, and might be in linux-tools package or similar"
+	echo "Must be run as sudo"
+	$(CC) $(SRC) $(MATH) -o $(OUTPUT)
+	sudo perf record ./$(OUTPUT)
+	sudo perf report
+	rm perf.data

test/test.c

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+#include "../squiggle.h"
+#include <stdint.h>
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define N 10 * 1000 * 1000
+
+void test_unit_uniform(uint32_t* seed){
+	float* unit_uniform_array = malloc(sizeof(float) * N);
+	
+	for(int i=0; i<N; i++){
+		unit_uniform_array[i] = sample_unit_uniform(seed);
+	}
+	
+	float mean = array_mean(unit_uniform_array, N);
+	float expected_mean = 0.5;
+	float delta_mean = mean - expected_mean;
+
+	float std = array_std(unit_uniform_array, N);
+	float expected_std = sqrt(1.0/12.0);
+	float 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) > 1.0/1000.0){
+		printf("[-] Mean test for unit uniform NOT passed.\n");
+	}else {
+		printf("[x] Mean test for unit uniform PASSED\n");
+	}
+
+	if(fabs(delta_std) > 1.0/1000.0){
+		printf("[-] Std test for unit uniform NOT passed.\n");
+	}else {
+		printf("[x] Std test for unit uniform PASSED\n");
+	}
+	
+	printf("\n");
+
+}
+
+void test_uniform(float start, float end, uint32_t* seed){
+	float* uniform_array = malloc(sizeof(float) * N);
+	
+	for(int i=0; i<N; i++){
+		uniform_array[i] = sample_uniform(start, end, seed);
+	}
+	
+	float mean = array_mean(uniform_array, N);
+	float expected_mean = (start + end) / 2; 
+	float delta_mean = mean - expected_mean;
+	
+	float std = array_std(uniform_array, N);
+	float expected_std = sqrt(1.0/12.0) * fabs(end-start);
+	float delta_std = std - expected_std;
+	
+
+	float width = fabs(end - start);
+	if(fabs(delta_mean) > width * 1.0/1000.0){
+		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 unit uniform PASSED\n");
+	}
+
+	if(fabs(delta_std) > width * 1.0/1000.0){
+		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);
+	}else {
+		printf("[x] Std test for unit uniform PASSED\n");
+	}
+	printf("\n");
+
+}
+
+int main(){
+    // set randomness seed
+    uint32_t* seed = malloc(sizeof(uint32_t));
+    *seed = 1000; // xorshift can't start with a seed of 0
+   
+		test_unit_uniform(seed);
+
+		for(int i=0; i<100; i++){
+			float start = sample_uniform(-10, 10, seed);
+			float end = sample_uniform(-10, 10, seed);
+			if ( end > start){
+				test_uniform(start, end, seed);
+			}
+		}
+		free(seed);
+}
+