Added a proper specification and minor cleanup.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403592

dlib/manifold_regularization/function_objects.h

@@ -41,6 +41,12 @@ namespace dlib
 
     struct use_gaussian_weights 
     {
+        use_gaussian_weights (
+        ) 
+        {
+            gamma = 0.1;
+        }
+
         use_gaussian_weights (
             double g
         )

dlib/manifold_regularization/function_objects_abstract.h

+// Copyright (C) 2010  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_MR_FUNCTION_ObJECTS_ABSTRACT_H__
+#ifdef DLIB_MR_FUNCTION_ObJECTS_ABSTRACT_H__
+
+#include "../matrix.h"
+#include <cmath>
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    struct squared_euclidean_distance
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This is a simple function object that computes squared euclidean distance
+                between two dlib::matrix objects.
+        !*/
+
+        template <typename sample_type>
+        double operator() (
+            const sample_type& a,
+            const sample_type& b
+        ) const;
+        /*!
+            requires
+                - sample_type should be a kind of dlib::matrix 
+            ensures
+                - returns length_squared(a-b);
+        !*/
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    struct use_weights_of_one 
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This is a simple function object that takes a single argument
+                and always returns 1 
+        !*/
+
+        template <typename edge_type>
+        double operator() (
+            const edge_type&
+        ) const;
+        /*!
+            ensures
+                - returns 1
+        !*/
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    struct use_gaussian_weights 
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This is a simple function object that takes a single argument
+                which should be an object similar to dlib::sample_pair.  
+        !*/
+
+        use_gaussian_weights (
+        );
+        /*!
+            ensures
+                - #gamma == 0.1
+        !*/
+
+        use_gaussian_weights (
+            double g
+        );
+        /*!
+            ensures
+                - #gamma == g
+        !*/
+
+        double gamma;
+
+        template <typename edge_type>
+        double operator() (
+            const edge_type& e
+        ) const;
+        /*!
+            requires
+                - e.distance() must be a valid expression that returns a number
+                  (e.g. edge_type might be dlib::sample_pair)
+            ensures
+                - returns std::exp(-gamma*e.distance());
+        !*/
+    };
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_MR_FUNCTION_ObJECTS_ABSTRACT_H__
+
+
+