Added unit tests for uniform_random_hash() and gaussian_random_hash().

dlib/test/rand.cpp

@@ -9,6 +9,7 @@
 #include <cmath>
 #include <dlib/rand.h>
 #include <dlib/compress_stream.h>
+#include <dlib/hash.h>
 
 #include "tester.h"
 
@@ -209,6 +210,7 @@ namespace
         rand_type& rnd
     )
     {
+        print_spinner();
         dlog << LINFO << "test normality";
         double cnt1 = 0; // num <= -1.2
         double cnt2 = 0; // num <= -0.5 
@@ -247,9 +249,137 @@ namespace
 
     }
 
+    void test_gaussian_random_hash()
+    {
+        print_spinner();
+        dlog << LINFO << "test_gaussian_random_hash()";
+        double cnt1 = 0; // num <= -1.2
+        double cnt2 = 0; // num <= -0.5 
+        double cnt3 = 0; // num <= 0
+        double cnt4 = 0; // num <= 0.5
+        double cnt5 = 0; // num <= 1.2
+
+        const unsigned long total = 1000000;
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = gaussian_random_hash(i,0,0);
+            if (r <= -1.2) cnt1 += 1;
+            if (r <= -0.5) cnt2 += 1;
+            if (r <=  0)   cnt3 += 1;
+            if (r <=  0.5) cnt4 += 1;
+            if (r <=  1.2) cnt5 += 1;
+        }
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = gaussian_random_hash(0,i,0);
+            if (r <= -1.2) cnt1 += 1;
+            if (r <= -0.5) cnt2 += 1;
+            if (r <=  0)   cnt3 += 1;
+            if (r <=  0.5) cnt4 += 1;
+            if (r <=  1.2) cnt5 += 1;
+        }
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = gaussian_random_hash(0,0,i);
+            if (r <= -1.2) cnt1 += 1;
+            if (r <= -0.5) cnt2 += 1;
+            if (r <=  0)   cnt3 += 1;
+            if (r <=  0.5) cnt4 += 1;
+            if (r <=  1.2) cnt5 += 1;
+        }
+
+        cnt1 /= total*3;
+        cnt2 /= total*3;
+        cnt3 /= total*3;
+        cnt4 /= total*3;
+        cnt5 /= total*3;
+
+        dlog << LINFO << "cnt1: "<< cnt1;
+        dlog << LINFO << "cnt2: "<< cnt2;
+        dlog << LINFO << "cnt3: "<< cnt3;
+        dlog << LINFO << "cnt4: "<< cnt4;
+        dlog << LINFO << "cnt5: "<< cnt5;
+
+        DLIB_TEST(std::abs(cnt1 - 0.11507) < 0.001);
+        DLIB_TEST(std::abs(cnt2 - 0.30854) < 0.001);
+        DLIB_TEST(std::abs(cnt3 - 0.5)     < 0.001);
+        DLIB_TEST(std::abs(cnt4 - 0.69146) < 0.001);
+        DLIB_TEST(std::abs(cnt5 - 0.88493) < 0.001);
+    }
+
+    void test_uniform_random_hash()
+    {
+        print_spinner();
+        dlog << LINFO << "test_uniform_random_hash()";
+        double cnt1 = 0; // num <= 0.2
+        double cnt2 = 0; // num <= 0.4 
+        double cnt3 = 0; // num <= 0.6
+        double cnt4 = 0; // num <= 0.8
+        double cnt5 = 0; // num <= 1.0
+
+        double min_val = 10;
+        double max_val = 0;
 
+        const unsigned long total = 1000000;
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = uniform_random_hash(i,0,0);
+            min_val = min(r,min_val);
+            max_val = max(r,max_val);
+
+            if (r <=  0.2) cnt1 += 1;
+            if (r <=  0.4) cnt2 += 1;
+            if (r <=  0.6) cnt3 += 1;
+            if (r <=  0.8) cnt4 += 1;
+            if (r <=  1.0) cnt5 += 1;
+        }
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = uniform_random_hash(0,i,0);
+            min_val = min(r,min_val);
+            max_val = max(r,max_val);
+
+            if (r <=  0.2) cnt1 += 1;
+            if (r <=  0.4) cnt2 += 1;
+            if (r <=  0.6) cnt3 += 1;
+            if (r <=  0.8) cnt4 += 1;
+            if (r <=  1.0) cnt5 += 1;
+        }
+        for (unsigned long i = 0; i < total; ++i)
+        {
+            const double r = uniform_random_hash(0,0,i);
+            min_val = min(r,min_val);
+            max_val = max(r,max_val);
+
+            if (r <=  0.2) cnt1 += 1;
+            if (r <=  0.4) cnt2 += 1;
+            if (r <=  0.6) cnt3 += 1;
+            if (r <=  0.8) cnt4 += 1;
+            if (r <=  1.0) cnt5 += 1;
+        }
 
+        cnt1 /= total*3;
+        cnt2 /= total*3;
+        cnt3 /= total*3;
+        cnt4 /= total*3;
+        cnt5 /= total*3;
 
+        dlog << LINFO << "cnt1: "<< cnt1;
+        dlog << LINFO << "cnt2: "<< cnt2;
+        dlog << LINFO << "cnt3: "<< cnt3;
+        dlog << LINFO << "cnt4: "<< cnt4;
+        dlog << LINFO << "cnt5: "<< cnt5;
+        dlog << LINFO << "min_val: "<< min_val;
+        dlog << LINFO << "max_val: "<< max_val;
+
+        DLIB_TEST(std::abs(cnt1 - 0.2) < 0.001);
+        DLIB_TEST(std::abs(cnt2 - 0.4) < 0.001);
+        DLIB_TEST(std::abs(cnt3 - 0.6) < 0.001);
+        DLIB_TEST(std::abs(cnt4 - 0.8) < 0.001);
+        DLIB_TEST(std::abs(cnt5 - 1.0) < 0.001);
+        DLIB_TEST(std::abs(min_val - 0.0) < 0.001);
+        DLIB_TEST(std::abs(max_val - 1.0) < 0.001);
+    }
 
     class rand_tester : public tester
     {
@@ -269,6 +399,8 @@ namespace
 
             dlib::rand rnd;
             test_normal_numbers(rnd);
+            test_gaussian_random_hash();
+            test_uniform_random_hash();
         }
     } a;