made the rank_features() function work with any kind of

vector like object

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402377

dlib/svm/feature_ranking.h

@@ -19,7 +19,7 @@ namespace dlib
         typename sample_matrix_type,
         typename label_matrix_type
         >
-    matrix<typename kernel_type::scalar_type,0,2,typename kernel_type::mem_manager_type> rank_features (
+    matrix<typename kernel_type::scalar_type,0,2,typename kernel_type::mem_manager_type> rank_features_impl (
         const kcentroid<kernel_type>& kc,
         const sample_matrix_type& samples,
         const label_matrix_type& labels,
@@ -131,6 +131,23 @@ namespace dlib
         return results;
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename kernel_type,
+        typename sample_matrix_type,
+        typename label_matrix_type
+        >
+    matrix<typename kernel_type::scalar_type,0,2,typename kernel_type::mem_manager_type> rank_features (
+        const kcentroid<kernel_type>& kc,
+        const sample_matrix_type& samples,
+        const label_matrix_type& labels,
+        const long num_features
+    )
+    {
+        return rank_features_impl(kc, vector_to_matrix(samples), vector_to_matrix(labels), num_features);
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/svm/feature_ranking_abstract.h

@@ -27,12 +27,11 @@ namespace dlib
     );
     /*!
         requires
-            - is_matrix<sample_matrix_type>::value == true
-              (i.e. samples must be a dlib matrix object)
-            - is_matrix<sample_matrix_type::type>::value == true
-              (i.e. samples must also contain dlib matrix objects)
-            - is_matrix<label_matrix_type>::value == true
-              (i.e. labels must be a dlib matrix object)
+            - vector_to_matrix(samples) == a valid matrix object
+            - vector_to_matrix(samples(0)) == a valid matrix object
+            - vector_to_matrix(labels) == a valid matrix object
+              (i.e. the 3 above things must either be dlib::matrix objects or be
+              convertable to them via the vector_to_matrix() function)
             - samples.nc() == 1 && labels.nc() == 1
               (i.e. samples and labels must be column vectors)
             - samples.size() == labels.size()