gdouble *vik_track_make_gradient_map ( const VikTrack *tr, guint16 num_chunks );
gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks );
gdouble *vik_track_make_distance_map ( const VikTrack *tr, guint16 num_chunks );
gdouble *vik_track_make_gradient_map ( const VikTrack *tr, guint16 num_chunks );
gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks );
gdouble *vik_track_make_distance_map ( const VikTrack *tr, guint16 num_chunks );