Added is_sequence_segmentation_problem()

dlib/svm/svm.h

@@ -198,6 +198,49 @@ namespace dlib
         return false;
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename sequence_type 
+        >
+    bool is_sequence_segmentation_problem (
+        const std::vector<sequence_type>& samples,
+        const std::vector<std::vector<std::pair<unsigned long,unsigned long> > >& segments
+    )
+    {
+        if (is_learning_problem(samples, segments))
+        {
+            for (unsigned long i = 0; i < samples.size(); ++i)
+            {
+                // Make sure the segments are inside samples[i] and don't overlap with each
+                // other.
+                std::vector<bool> hits(samples[i].size(), false);
+                for (unsigned long j = 0; j < segments[i].size(); ++j)
+                {
+                    const unsigned long begin = segments[i][j].first;
+                    const unsigned long end = segments[i][j].second;
+                    // if the segment is outside the sequence
+                    if (end > samples[i].size())
+                        return false;
+
+                    if (begin > end)
+                        return false;
+
+                    // check for overlap
+                    for (unsigned long k = begin; k < end; ++k)
+                    {
+                        if (hits[k])
+                            return false;
+                        hits[k] = true;
+                    }
+                }
+            }
+            return true;
+        }
+
+        return false;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <

dlib/svm/svm_abstract.h

@@ -40,6 +40,8 @@ namespace dlib
                 - x.size() > 0
     !*/
 
+// ----------------------------------------------------------------------------------------
+
     template <
         typename T,
         typename U
@@ -62,6 +64,8 @@ namespace dlib
                     - x_labels(i) == -1 or +1
     !*/
 
+// ----------------------------------------------------------------------------------------
+
     template <
         typename sequence_type 
         >
@@ -79,6 +83,33 @@ namespace dlib
                       its corresponding sample sequence)
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename sequence_type 
+        >
+    bool is_sequence_segmentation_problem (
+        const std::vector<sequence_type>& samples,
+        const std::vector<std::vector<std::pair<unsigned long,unsigned long> > >& segments
+    );
+    /*!
+        ensures
+            - returns true if all of the following are true and false otherwise:
+                - is_learning_problem(samples, segments) == true
+                - for all valid i:
+                    - for all valid j:
+                        - We interpret segments[i][j] as defining a half open range
+                          starting with segments[i][j].first and ending just before
+                          segments[i][j].second.
+                        - segments[i][j].first <= segments[i][j].second
+                        - segments[i][j].second <= samples[i].size()
+                          (i.e. Each segment must be contained within its associated sequence)
+                        - segments[i][j] does not overlap with any of the other ranges in
+                          segments[i].
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
     template <
         typename lhs_type, 
         typename rhs_type
@@ -106,6 +137,8 @@ namespace dlib
                       in samples[i].second.
     !*/
 
+// ----------------------------------------------------------------------------------------
+
     template <
         typename lhs_type, 
         typename rhs_type