Added the null_trainer_type object.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403037

dlib/svm.h

@@ -15,6 +15,7 @@
 #include "svm/rvm.h"
 #include "svm/pegasos.h"
 #include "svm/sparse_kernel.h"
+#include "svm/null_trainer.h"
 
 #endif // DLIB_SVm_HEADER
 

dlib/svm/null_trainer.h

+// Copyright (C) 2009  Davis E. King (davisking@users.sourceforge.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_NULL_TRAINERs_H_
+#define DLIB_NULL_TRAINERs_H_
+
+#include "null_trainer_abstract.h"
+#include "../algs.h"
+#include "function_abstract.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename dec_funct_type 
+        >
+    class null_trainer_type
+    {
+    public:
+        typedef typename dec_funct_type::kernel_type kernel_type;
+        typedef typename dec_funct_type::scalar_type scalar_type;
+        typedef typename dec_funct_type::sample_type sample_type;
+        typedef typename dec_funct_type::mem_manager_type mem_manager_type;
+        typedef dec_funct_type trained_function_type;
+
+        null_trainer_type (
+        ){}
+
+        null_trainer_type (
+            const dec_funct_type& dec_funct_
+        ) : dec_funct(dec_funct_) {}
+
+        template <
+            typename in_sample_vector_type,
+            typename in_scalar_vector_type
+            >
+        const dec_funct_type& train (
+            const in_sample_vector_type& ,
+            const in_scalar_vector_type& 
+        ) const { return dec_funct; }
+
+    private:
+        dec_funct_type dec_funct;
+    }; 
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename dec_funct_type
+        >
+    const null_trainer_type<dec_funct_type> null_trainer (
+        const dec_funct_type& dec_funct
+    ) { return null_trainer_type<dec_funct_type>(dec_funct); }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_NULL_TRAINERs_H_
+

dlib/svm/null_trainer_abstract.h

+// Copyright (C) 2009  Davis E. King (davisking@users.sourceforge.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_NULL_TRAINERs_ABSTRACT_
+#ifdef DLIB_NULL_TRAINERs_ABSTRACT_
+
+#include "../algs.h"
+#include "function_abstract.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename dec_funct_type 
+        >
+    class null_trainer_type
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This object is a simple tool for turning a decision function 
+                into a trainer object that always returns the original decision
+                function when you try to train with it.  
+
+                dlib contains a few "training post processing" algorithms (e.g. 
+                reduced and reduced2()).  These tools take in a trainer object,
+                tell it to perform training, and then they take the output decision
+                function and do some kind of post processing to it.  The null_trainer_type 
+                object is useful because you can use it to run an already
+                learned decision function through the training post processing
+                algorithms by turning a decision function into a null_trainer_type
+                and then giving it to a post processor.  
+        !*/
+
+    public:
+        typedef typename dec_funct_type::kernel_type kernel_type;
+        typedef typename dec_funct_type::scalar_type scalar_type;
+        typedef typename dec_funct_type::sample_type sample_type;
+        typedef typename dec_funct_type::mem_manager_type mem_manager_type;
+        typedef dec_funct_type trained_function_type;
+
+        null_trainer_type (
+        );
+        /*!
+            ensures
+                - any call to this->train(x,y) will return a default initialized
+                  dec_funct_type object.
+        !*/
+
+        null_trainer_type (
+            const dec_funct_type& dec_funct
+        );
+        /*!
+            ensures
+                - any call to this->train(x,y) will always return a copy of
+                  the given dec_funct object.
+        !*/
+
+        template <
+            typename in_sample_vector_type,
+            typename in_scalar_vector_type
+            >
+        const dec_funct_type& train (
+            const in_sample_vector_type& x,
+            const in_scalar_vector_type& y
+        ) const;
+        /*!
+            ensures
+                - returns a copy of the decision function object given to
+                  this object's constructor.
+        !*/
+
+    }; 
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename dec_funct_type
+        >
+    const null_trainer_type<dec_funct_type> null_trainer (
+        const dec_funct_type& dec_funct
+    ) { return null_trainer_type<dec_funct_type>(dec_funct); }
+    /*!
+        ensures
+            - returns a null_trainer_type object that has been instantiated with 
+              the given arguments.  That is, this function returns a null_trainer_type
+              trainer that will return a copy of the given dec_funct object every time 
+              someone calls its train() function.
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_NULL_TRAINERs_ABSTRACT_
+
+