implement split by daybreak

tests/test_trajectory.py

@@ -232,15 +232,30 @@ def test_get_length_euclidiean(self):
     def test_get_direction(self):
         df = pd.DataFrame([
             {'geometry':Point(0,0), 't':datetime(2018,1,1,12,0,0)},
-            {'geometry':Point(-6,10), 't':datetime(2018,1,1,12,0,0)},
-            {'geometry':Point(6,6), 't':datetime(2018,1,1,12,0,1)}
+            {'geometry':Point(-6,10), 't':datetime(2018,1,1,12,0,1)},
+            {'geometry':Point(6,6), 't':datetime(2018,1,1,12,0,2)}
             ]).set_index('t')
         geo_df = GeoDataFrame(df, crs={'init': '31256'})
         traj = Trajectory(1,geo_df)
         result = traj.get_direction()
         expected_result = 45
         self.assertAlmostEqual(result, expected_result, 1)
 
+    def test_split_by_daybreak(self):
+        df = pd.DataFrame([
+            {'geometry':Point(0,0), 't':datetime(2018,1,1,12,0,0)},
+            {'geometry':Point(-6,10), 't':datetime(2018,1,1,12,1,0)},
+            {'geometry':Point(6,6), 't':datetime(2018,1,3,12,0,1)},
+            {'geometry':Point(6,16), 't':datetime(2018,1,3,12,5,1)}
+            ]).set_index('t')
+        geo_df = GeoDataFrame(df, crs={'init': '31256'})
+        traj = Trajectory(1,geo_df)
+        split = traj.split('daybreak')
+        result = len(split)
+        expected_result = 2
+        self.assertEqual(result, expected_result)
+
+
 
 if __name__ == '__main__':
     unittest.main()

trajectory.py

@@ -206,3 +206,15 @@ def clip(self, polygon):
 
     def intersection(self, feature):
         return overlay.intersection(self, feature)
+
+    def split(self, mode='daybreak'):
+        result = []
+        if mode == 'daybreak':
+            dfs = [group[1] for group in self.df.groupby(self.df.index.day)]
+            for i, df in enumerate(dfs):
+                result.append(Trajectory('{}_{}'.format(self.id, i), df))
+        else:
+            raise ValueError('Invalid split mode {}. Must be one of [daybreak]'.format(mode))
+        return result
+
+