Simplified the sequence_labeler interface a bit.

dlib/svm/sequence_labeler.h

@@ -186,6 +186,21 @@ namespace dlib
             weights = 0;
         }
 
+        explicit sequence_labeler(
+            const matrix<double,0,1>& weights_
+        ) : 
+            weights(weights_)
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT(fe.num_features() == static_cast<unsigned long>(weights_.size()),
+                "\t sequence_labeler::sequence_labeler(weights_)"
+                << "\n\t These sizes should match"
+                << "\n\t fe.num_features(): " << fe.num_features() 
+                << "\n\t weights_.size():   " << weights_.size() 
+                << "\n\t this: " << this
+                );
+        }
+
         sequence_labeler(
             const feature_extractor& fe_,
             const matrix<double,0,1>& weights_
@@ -195,7 +210,7 @@ namespace dlib
         {
             // make sure requires clause is not broken
             DLIB_ASSERT(fe_.num_features() == static_cast<unsigned long>(weights_.size()),
-                "\t sequence_labeler::sequence_labeler()"
+                "\t sequence_labeler::sequence_labeler(fe_,weights_)"
                 << "\n\t These sizes should match"
                 << "\n\t fe_.num_features(): " << fe_.num_features() 
                 << "\n\t weights_.size():    " << weights_.size() 

dlib/svm/sequence_labeler_abstract.h

@@ -196,9 +196,22 @@ namespace dlib
         );
         /*!
             ensures
-                - #get_weights().size() == fe.num_features()
+                - #get_feature_extractor() == feature_extractor() 
+                  (i.e. it will have its default value)
+                - #get_weights().size() == #get_feature_extractor().num_features()
                 - #get_weights() == 0
-                - #get_feature_extractor() will have an initial value for its type
+        !*/
+
+        explicit sequence_labeler(
+            const matrix<double,0,1>& weights
+        ); 
+        /*!
+            requires
+                - feature_extractor().num_features() == weights.size()
+            ensures
+                - #get_feature_extractor() == feature_extractor() 
+                  (i.e. it will have its default value)
+                - #get_weights() == weights
         !*/
 
         sequence_labeler(

examples/sequence_labeler_ex.cpp

@@ -162,7 +162,7 @@ int main()
     matrix<double,0,1> true_hmm_model_weights = log(join_cols(reshape_to_column_vector(transition_probabilities),
                                                               reshape_to_column_vector(emission_probabilities)));
 
-    sequence_labeler<feature_extractor> labeler_true(feature_extractor(), true_hmm_model_weights); 
+    sequence_labeler<feature_extractor> labeler_true(true_hmm_model_weights); 
 
     confusion_matrix = test_sequence_labeler(labeler_true, samples, labels);
     cout << "\nTrue HMM model: " << endl;