Made running_stats serializable.

dlib/statistics/statistics.h

@@ -158,6 +158,18 @@ namespace dlib
             return (val-mean())/std::sqrt(variance());
         }
 
+        template <typename U>
+        friend void serialize (
+            const running_stats<U>& item, 
+            std::ostream& out 
+        );
+
+        template <typename U>
+        friend void deserialize (
+            running_stats<U>& item, 
+            std::istream& in
+        ); 
+
     private:
         T sum;
         T sum_sqr;
@@ -167,6 +179,34 @@ namespace dlib
         T max_value;
     };
 
+    template <typename T>
+    void serialize (
+        const running_stats<T>& item, 
+        std::ostream& out 
+    )
+    {
+        serialize(item.sum, out);
+        serialize(item.sum_sqr, out);
+        serialize(item.n, out);
+        serialize(item.maximum_n, out);
+        serialize(item.min_value, out);
+        serialize(item.max_value, out);
+    }
+
+    template <typename T>
+    void deserialize (
+        running_stats<T>& item, 
+        std::istream& in
+    ) 
+    {
+        deserialize(item.sum, in);
+        deserialize(item.sum_sqr, in);
+        deserialize(item.n, in);
+        deserialize(item.maximum_n, in);
+        deserialize(item.min_value, in);
+        deserialize(item.max_value, in);
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <

dlib/statistics/statistics_abstract.h

@@ -157,6 +157,24 @@ namespace dlib
         !*/
     };
 
+    template <typename T>
+    void serialize (
+        const running_stats<T>& item, 
+        std::ostream& out 
+    );
+    /*!
+        provides serialization support 
+    !*/
+
+    template <typename T>
+    void deserialize (
+        running_stats<T>& item, 
+        std::istream& in
+    );
+    /*!
+        provides serialization support 
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     template <

dlib/test/statistics.cpp

@@ -195,7 +195,7 @@ namespace
         {
             print_spinner();
 
-            running_stats<double> rs;
+            running_stats<double> rs, rs2;
 
             running_scalar_covariance<double> rsc1, rsc2;
 
@@ -208,7 +208,6 @@ namespace
                 rsc2.add(i,-i);
             }
 
-
             // make sure the running_stats and running_scalar_covariance agree
             DLIB_TEST_MSG(std::abs(rs.mean() - rsc1.mean_x()) < 1e-10, std::abs(rs.mean() - rsc1.mean_x()));
             DLIB_TEST(std::abs(rs.mean() - rsc1.mean_y()) < 1e-10);
@@ -220,6 +219,23 @@ namespace
 
             DLIB_TEST(std::abs(rsc1.correlation() - 1) < 1e-10);
             DLIB_TEST(std::abs(rsc2.correlation() - 0) < 1e-10);
+
+
+
+            // test serialization of running_stats
+            ostringstream sout;
+            serialize(rs, sout);
+            istringstream sin(sout.str());
+            deserialize(rs2, sin);
+            // make sure the running_stats and running_scalar_covariance agree
+            DLIB_TEST_MSG(std::abs(rs2.mean() - rsc1.mean_x()) < 1e-10, std::abs(rs2.mean() - rsc1.mean_x()));
+            DLIB_TEST(std::abs(rs2.mean() - rsc1.mean_y()) < 1e-10);
+            DLIB_TEST(std::abs(rs2.stddev() - rsc1.stddev_x()) < 1e-10);
+            DLIB_TEST(std::abs(rs2.stddev() - rsc1.stddev_y()) < 1e-10);
+            DLIB_TEST(std::abs(rs2.variance() - rsc1.variance_x()) < 1e-10);
+            DLIB_TEST(std::abs(rs2.variance() - rsc1.variance_y()) < 1e-10);
+            DLIB_TEST(rs2.current_n() == rsc1.current_n());
+
         }
 
         void perform_test (