fix floats.h bug, fix std bug, add tests for std.

squiggle.c

@@ -1,4 +1,4 @@
-#include <double.h>
+#include <float.h>
 #include <limits.h>
 #include <math.h>
 #include <stdint.h>
@@ -161,8 +161,7 @@ double array_std(double* array, int length)
     double mean = array_mean(array, length);
     double std = 0.0;
     for (int i = 0; i < length; i++) {
-        std += (array[i] - mean);
+        std += (array[i] - mean) * (array[i] - mean);
-				std *= std;
     }
     std = sqrt(std / length);
     return std;

test/makefile

@@ -36,6 +36,9 @@ format: $(SRC)
 run: $(SRC) $(OUTPUT)
 	./$(OUTPUT)
 
+verify: $(SRC) $(OUTPUT)
+	./$(OUTPUT) | grep "NOT passed" || true
+
 time-linux: 
 	@echo "Requires /bin/time, found on GNU/Linux systems" && echo
 	

test/test.c

@@ -4,7 +4,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-#define N  100
+#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);
@@ -24,13 +25,13 @@ void test_unit_uniform(uint64_t* seed){
 	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){
+	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) > 1.0/1000.0){
+	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");
@@ -56,22 +57,22 @@ void test_uniform(double start, double end, uint64_t* seed){
 	double delta_std = std - expected_std;
 	
 	double width = fabs(end - start);
-	if(fabs(delta_mean) > width * 1.0/1000.0){
+	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 unit uniform PASSED\n");
+		printf("[x] Mean test for [%.1f, %.1f] uniform PASSED\n", start, end);
 	}
 
-	if(fabs(delta_std) > width * 1.0/1000.0){
+	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<N; i++){
+		for(int i=0; i<10; i++){
 
 			printf("%.1f, ", uniform_array[i]);
 		}
 	}else {
-		printf("[x] Std test for unit uniform PASSED\n");
+		printf("[x] Std test for [%.1f, %.1f] uniform PASSED\n", start, end);
 	}
 	printf("\n");
 
@@ -82,15 +83,27 @@ int main(){
     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);
 
-		for(int i=0; i<1; i++){
+		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);
 }