I changed the sequence labeling stuff to allow a user defined

sequence type.  So these changes are basically just renaming some
template arguments and minor changes to some typedefs.

dlib/svm/cross_validate_sequence_labeler.h

@@ -16,11 +16,11 @@ namespace dlib
 
     template <
         typename sequence_labeler_type,
-        typename sample_type
+        typename sequence_type 
         >
     const matrix<double> test_sequence_labeler (
         const sequence_labeler_type& labeler,
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels
     )
     {
@@ -59,11 +59,11 @@ namespace dlib
 
     template <
         typename trainer_type,
-        typename sample_type
+        typename sequence_type
         >
     const matrix<double> cross_validate_sequence_labeler (
         const trainer_type& trainer,
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels,
         const long folds
     )
@@ -102,7 +102,7 @@ namespace dlib
         const long num_in_test = samples.size()/folds;
         const long num_in_train = samples.size() - num_in_test;
 
-        std::vector<std::vector<sample_type> > x_test, x_train;
+        std::vector<sequence_type> x_test, x_train;
         std::vector<std::vector<unsigned long> > y_test, y_train;
 
 

dlib/svm/cross_validate_sequence_labeler_abstract.h

@@ -15,11 +15,11 @@ namespace dlib
 
     template <
         typename sequence_labeler_type,
-        typename sample_type
+        typename sequence_type 
         >
     const matrix<double> test_sequence_labeler (
         const sequence_labeler_type& labeler,
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels
     );
     /*!
@@ -43,11 +43,11 @@ namespace dlib
 
     template <
         typename trainer_type,
-        typename sample_type
+        typename sequence_type
         >
     const matrix<double> cross_validate_sequence_labeler (
         const trainer_type& trainer,
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels,
         const long folds
     );

dlib/svm/sequence_labeler.h

@@ -39,11 +39,11 @@ namespace dlib
             double value;
         };
 
-        template <typename feature_extractor, typename EXP, typename sample_type, typename EXP2> 
+        template <typename feature_extractor, typename EXP, typename sequence_type, typename EXP2> 
         double dot(
             const matrix_exp<EXP>& lambda,
             const feature_extractor& fe,
-            const std::vector<sample_type>& sequence,
+            const sequence_type& sequence,
             const matrix_exp<EXP2>& candidate_labeling,
             unsigned long position
         )
@@ -61,7 +61,7 @@ namespace dlib
     {
         template <
             typename T,
-            bool (T::*funct)(const std::vector<typename T::sample_type>&, const matrix_exp<matrix<unsigned long> >&, unsigned long)const
+            bool (T::*funct)(const typename T::sequence_type&, const matrix_exp<matrix<unsigned long> >&, unsigned long)const
             >
         struct hrlh_helper
         {
@@ -100,10 +100,10 @@ namespace dlib
         };
 
 
-        template <typename feature_extractor, typename EXP, typename sample_type>
+        template <typename feature_extractor, typename EXP, typename sequence_type>
         typename enable_if<has_reject_labeling<feature_extractor>,bool>::type call_reject_labeling_if_exists (
             const feature_extractor& fe,
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         )
@@ -111,10 +111,10 @@ namespace dlib
             return fe.reject_labeling(x, y, position);
         }
 
-        template <typename feature_extractor, typename EXP, typename sample_type>
+        template <typename feature_extractor, typename EXP, typename sequence_type>
         typename disable_if<has_reject_labeling<feature_extractor>,bool>::type call_reject_labeling_if_exists (
             const feature_extractor& ,
-            const std::vector<sample_type>& ,
+            const sequence_type& ,
             const matrix_exp<EXP>& ,
             unsigned long 
         )
@@ -131,7 +131,7 @@ namespace dlib
         >
     typename enable_if<dlib::impl::has_reject_labeling<feature_extractor>,bool>::type contains_invalid_labeling (
         const feature_extractor& fe,
-        const std::vector<typename feature_extractor::sample_type>& x,
+        const typename feature_extractor::sequence_type& x,
         const std::vector<unsigned long>& y
     )
     {
@@ -160,7 +160,7 @@ namespace dlib
         >
     typename disable_if<dlib::impl::has_reject_labeling<feature_extractor>,bool>::type contains_invalid_labeling (
         const feature_extractor& ,
-        const std::vector<typename feature_extractor::sample_type>& x,
+        const typename feature_extractor::sequence_type& x,
         const std::vector<unsigned long>& y 
     )
     {
@@ -177,7 +177,7 @@ namespace dlib
         >
     bool contains_invalid_labeling (
         const feature_extractor& fe,
-        const std::vector<std::vector<typename feature_extractor::sample_type> >& x,
+        const std::vector<typename feature_extractor::sequence_type>& x,
         const std::vector<std::vector<unsigned long> >& y
     )
     {
@@ -201,8 +201,7 @@ namespace dlib
     class sequence_labeler
     {
     public:
-        typedef typename feature_extractor::sample_type sample_type;
-        typedef std::vector<sample_type> sample_sequence_type;
+        typedef typename feature_extractor::sequence_type sample_sequence_type;
         typedef std::vector<unsigned long> labeled_sequence_type;
 
     private:

dlib/svm/sequence_labeler_abstract.h

@@ -42,8 +42,9 @@ namespace dlib
         !*/
 
     public:
-        // This should be the type of elements in the input sequence
-        typedef the_type_of_elements_of_x sample_type;
+        // This should be the type used to represent an input sequence.  It can be
+        // anything so long as it has a .size() which returns the length of the sequence.
+        typedef the_type_used_to_represent_a_sequence sequence_type;
 
         example_feature_extractor (
         ); 
@@ -81,7 +82,7 @@ namespace dlib
 
         template <typename EXP>
         bool reject_labeling (
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         ) const;
@@ -110,7 +111,7 @@ namespace dlib
         template <typename feature_setter, typename EXP>
         void get_features (
             feature_setter& set_feature,
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         ) const;
@@ -173,7 +174,7 @@ namespace dlib
         >
     bool contains_invalid_labeling (
         const feature_extractor& fe,
-        const std::vector<typename feature_extractor::sample_type>& x,
+        const typename feature_extractor::sequence_type& x,
         const std::vector<unsigned long>& y
     );
     /*!
@@ -195,7 +196,7 @@ namespace dlib
         >
     bool contains_invalid_labeling (
         const feature_extractor& fe,
-        const std::vector<std::vector<typename feature_extractor::sample_type> >& x,
+        const std::vector<typename feature_extractor::sequence_type>& x,
         const std::vector<std::vector<unsigned long> >& y
     );
     /*!
@@ -243,8 +244,7 @@ namespace dlib
         !*/
 
     public:
-        typedef typename feature_extractor::sample_type sample_type;
-        typedef std::vector<sample_type> sample_sequence_type;
+        typedef typename feature_extractor::sequence_type sample_sequence_type;
         typedef std::vector<unsigned long> labeled_sequence_type;
 
         sequence_labeler(

dlib/svm/structural_sequence_labeling_trainer.h

@@ -20,8 +20,7 @@ namespace dlib
     class structural_sequence_labeling_trainer
     {
     public:
-        typedef typename feature_extractor::sample_type sample_type;
-        typedef std::vector<sample_type> sample_sequence_type;
+        typedef typename feature_extractor::sequence_type sample_sequence_type;
         typedef std::vector<unsigned long> labeled_sequence_type;
 
         typedef sequence_labeler<feature_extractor> trained_function_type;

dlib/svm/structural_sequence_labeling_trainer_abstract.h

@@ -36,8 +36,7 @@ namespace dlib
         !*/
 
     public:
-        typedef typename feature_extractor::sample_type sample_type;
-        typedef std::vector<sample_type>   sample_sequence_type;
+        typedef typename feature_extractor::sequence_type sample_sequence_type;
         typedef std::vector<unsigned long> labeled_sequence_type;
         typedef sequence_labeler<feature_extractor> trained_function_type;
 

dlib/svm/structural_svm_sequence_labeling_problem.h

@@ -44,11 +44,11 @@ namespace dlib
 
     // ----------------------------------------------------------------------------------------
 
-        template <typename feature_extractor, typename sample_type, typename EXP2> 
+        template <typename feature_extractor, typename sequence_type, typename EXP2> 
         void get_feature_vector(
             std::vector<std::pair<unsigned long, double> >& feats,
             const feature_extractor& fe,
-            const std::vector<sample_type>& sequence,
+            const sequence_type& sequence,
             const matrix_exp<EXP2>& candidate_labeling,
             unsigned long position
         )
@@ -71,10 +71,10 @@ namespace dlib
         typedef matrix<double,0,1> matrix_type;
         typedef std::vector<std::pair<unsigned long, double> > feature_vector_type;
 
-        typedef typename feature_extractor::sample_type sample_type;
+        typedef typename feature_extractor::sequence_type sequence_type;
 
         structural_svm_sequence_labeling_problem(
-            const std::vector<std::vector<sample_type> >& samples_,
+            const std::vector<sequence_type>& samples_,
             const std::vector<std::vector<unsigned long> >& labels_,
             const feature_extractor& fe_,
             unsigned long num_threads = 2
@@ -130,7 +130,7 @@ namespace dlib
         }
 
         void get_joint_feature_vector (
-            const std::vector<sample_type>& sample, 
+            const sequence_type& sample, 
             const std::vector<unsigned long>& label,
             feature_vector_type& psi
         ) const 
@@ -163,7 +163,7 @@ namespace dlib
             unsigned long num_states() const { return fe.num_labels(); }
 
             map_prob(
-                const std::vector<sample_type>& sequence_,
+                const sequence_type& sequence_,
                 const std::vector<unsigned long>& label_,
                 const feature_extractor& fe_,
                 const matrix<double,0,1>& weights_
@@ -199,7 +199,7 @@ namespace dlib
                 return fe_helpers::dot(weights, fe, sequence, node_states, node_id) + loss;
             }
 
-            const std::vector<sample_type>& sequence;
+            const sequence_type& sequence;
             const std::vector<unsigned long>& label;
             const feature_extractor& fe;
             const matrix<double,0,1>& weights;
@@ -225,7 +225,7 @@ namespace dlib
             get_joint_feature_vector(samples[idx], y, psi);
         }
 
-        const std::vector<std::vector<sample_type> >& samples;
+        const std::vector<sequence_type>& samples;
         const std::vector<std::vector<unsigned long> >& labels;
         const feature_extractor& fe;
     };

dlib/svm/structural_svm_sequence_labeling_problem_abstract.h

@@ -40,10 +40,10 @@ namespace dlib
         !*/
 
     public:
-        typedef typename feature_extractor::sample_type sample_type;
+        typedef typename feature_extractor::sequence_type sequence_type;
 
         structural_svm_sequence_labeling_problem(
-            const std::vector<std::vector<sample_type> >& samples,
+            const std::vector<sequence_type>& samples,
             const std::vector<std::vector<unsigned long> >& labels,
             const feature_extractor& fe,
             unsigned long num_threads = 2

dlib/svm/svm.h

@@ -178,10 +178,10 @@ namespace dlib
 // ----------------------------------------------------------------------------------------
 
     template <
-        typename sample_type
+        typename sequence_type 
         >
     bool is_sequence_labeling_problem (
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels
     )
     {

dlib/svm/svm_abstract.h

@@ -63,10 +63,10 @@ namespace dlib
     !*/
 
     template <
-        typename sample_type
+        typename sequence_type 
         >
     bool is_sequence_labeling_problem (
-        const std::vector<std::vector<sample_type> >& samples,
+        const std::vector<sequence_type>& samples,
         const std::vector<std::vector<unsigned long> >& labels
     );
     /*!

dlib/test/sequence_labeler.cpp

@@ -24,12 +24,26 @@ namespace
     const unsigned long num_label_states = 3; // the "hidden" states
     const unsigned long num_sample_states = 3;
 
+// ----------------------------------------------------------------------------------------
+
+    struct funny_sequence
+    {
+        std::vector<unsigned long> item;
+        unsigned long size() const { return item.size(); }
+    };
+    funny_sequence make_funny_sequence(const std::vector<unsigned long>& item)
+    {
+        funny_sequence temp;
+        temp.item = item;
+        return temp;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     class feature_extractor
     {
     public:
-        typedef unsigned long sample_type; 
+        typedef funny_sequence sequence_type; 
 
         unsigned long num_features() const
         {
@@ -49,7 +63,7 @@ namespace
         template <typename feature_setter, typename EXP>
         void get_features (
             feature_setter& set_feature,
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         ) const
@@ -58,14 +72,14 @@ namespace
                 set_feature(y(1)*num_label_states + y(0));
 
             set_feature(num_label_states*num_label_states +
-                        y(0)*num_sample_states + x[position]);
+                        y(0)*num_sample_states + x.item[position]);
         }
     };
 
     class feature_extractor_partial
     {
     public:
-        typedef unsigned long sample_type; 
+        typedef funny_sequence sequence_type; 
 
         unsigned long num_features() const
         {
@@ -85,7 +99,7 @@ namespace
         template <typename feature_setter, typename EXP>
         void get_features (
             feature_setter& set_feature,
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         ) const
@@ -97,9 +111,9 @@ namespace
             }
 
             set_feature(num_label_states*num_label_states +
-                        y(0)*num_sample_states + x[position],0.4);
+                        y(0)*num_sample_states + x.item[position],0.4);
             set_feature(num_label_states*num_label_states +
-                        y(0)*num_sample_states + x[position],0.6);
+                        y(0)*num_sample_states + x.item[position],0.6);
         }
     };
 
@@ -107,7 +121,7 @@ namespace
     class feature_extractor2
     {
     public:
-        typedef unsigned long sample_type; 
+        typedef funny_sequence sequence_type; 
 
         unsigned long num_features() const
         {
@@ -126,7 +140,7 @@ namespace
 
         template <typename EXP>
         bool reject_labeling (
-            const std::vector<sample_type>& ,
+            const sequence_type& ,
             const matrix_exp<EXP>& ,
             unsigned long 
         ) const
@@ -138,7 +152,7 @@ namespace
         template <typename feature_setter, typename EXP>
         void get_features (
             feature_setter& set_feature,
-            const std::vector<sample_type>& x,
+            const sequence_type& x,
             const matrix_exp<EXP>& y,
             unsigned long position
         ) const
@@ -147,7 +161,7 @@ namespace
                 set_feature(y(1)*num_label_states + y(0));
 
             set_feature(num_label_states*num_label_states +
-                        y(0)*num_sample_states + x[position]);
+                        y(0)*num_sample_states + x.item[position]);
         }
     };
 
@@ -207,7 +221,7 @@ namespace
     void make_dataset (
         const matrix<double>& transition_probabilities,
         const matrix<double>& emission_probabilities,
-        std::vector<std::vector<unsigned long> >& samples,
+        std::vector<funny_sequence>& samples,
         std::vector<std::vector<unsigned long> >& labels,
         unsigned long dataset_size
     )
@@ -258,7 +272,7 @@ namespace
                 previous_label = next_label;
             }
 
-            samples.push_back(sample);
+            samples.push_back(make_funny_sequence(sample));
             labels.push_back(label);
         }
     }
@@ -283,7 +297,7 @@ namespace
         print_spinner();
 
 
-        std::vector<std::vector<unsigned long> > samples;
+        std::vector<funny_sequence> samples;
         std::vector<std::vector<unsigned long> > labels;
         make_dataset(transition_probabilities,emission_probabilities, 
                      samples, labels, 1000);
@@ -294,7 +308,7 @@ namespace
         for (int i = 0; i < 10; ++i)
         {
             dlog << LINFO << "hidden states:   " << trans(vector_to_matrix(labels[i]));
-            dlog << LINFO << "observed states: " << trans(vector_to_matrix(samples[i]));
+            dlog << LINFO << "observed states: " << trans(vector_to_matrix(samples[i].item));
             dlog << LINFO << "******************************";
         }
 
@@ -377,7 +391,7 @@ namespace
         */
 
         print_spinner();
-        std::vector<std::vector<unsigned long> > samples;
+        std::vector<funny_sequence> samples;
         std::vector<std::vector<unsigned long> > labels;
 
         matrix<double> transition_probabilities(num_label_states, num_label_states);

examples/sequence_labeler_ex.cpp

@@ -67,9 +67,10 @@ class feature_extractor
     */
 
 public:
-    // This defines the type used to represent the elements of an observed 
-    // sequence.  You can use any type here.  
-    typedef unsigned long sample_type; 
+    // This defines the type used to represent the observed sequence.  You can use 
+    // any type here so long as it has a .size() which returns the number of things
+    // in the sequence.  
+    typedef std::vector<unsigned long> sequence_type; 
 
     unsigned long num_features() const
     /*!
@@ -111,7 +112,7 @@ public:
     template <typename feature_setter, typename EXP>
     void get_features (
         feature_setter& set_feature,
-        const std::vector<sample_type>& x,
+        const sequence_type& x,
         const matrix_exp<EXP>& y,
         unsigned long position
     ) const