Issues following example docs

Hi @anitagraser

I have been working through the examples at https://anitagraser.github.io/movingpandas/

It all works well except for the last couple of examples embedded in the images at the end of the page (for calculating stops and splits):

import pandas as pd
import geopandas as gp
import psycopg2
import movingpandas as mpd
from datetime import timedelta

con = psycopg2.connect(database="gis", user="docker", password="xxxxxxxxx",
    host="db", sslmode="require")

sql = "select geom, id, device, event_datetime from owntracks.event order by event_datetime ASC"

df = gp.GeoDataFrame.from_postgis(sql, con, geom_col='geom' )

df.plot()

<AxesSubplot:>

traj = mpd.Trajectory(df, 1)

traj.plot()

<AxesSubplot:>





![output_6_1](https://user-images.githubusercontent.com/178003/136838243-33b1d04c-b6d5-43f7-9a3b-9be060c6d7b6.png)

traj.hvplot(geo=True, tiles=‘OSM’, line_width=5, frame_width=300, frame_height=300)

df.columns

Index(['geom', 'id', 'device', 'event_datetime'], dtype='object')

df

<div> <style scoped> .dataframe tbody tr th:only-of-type { vertical-align: middle; }

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

</style>

	geom	id	device	event_datetime
0	POINT (xxx,yyy)	8807	TP	2021-09-21 18:41:26
1	POINT (xxx,yyy)	8814	TP	2021-09-21 18:41:26
2	POINT (xxx,yyy)	59819	TP	2021-09-21 18:41:26
3	POINT (xxx,yyy)	8849	TP	2021-09-21 18:41:26
4	POINT (xxx,yyy)	8869	TP	2021-09-21 18:41:26
...	...	...	...	...
67954	POINT (xxx,yyy)	68106	TP	2021-10-11 19:18:44
67955	POINT (xxx,yyy)	68107	TP	2021-10-11 19:18:52
67956	POINT (xxx,yyy)	68108	TP	2021-10-11 19:18:57
67957	POINT (xxx,yyy)	68109	TP	2021-10-11 19:19:19
67958	POINT (xxx,yyy)	68110	TP	2021-10-11 19:19:19

67959 rows × 4 columns

</div>

df = df.set_index('event_datetime')

tc = mpd.TrajectoryCollection(df, 'device')

daily = mpd.TemporalSplitter(tc).split(mode='day')

daily_lengths = [traj.get_length() for traj in daily]

daily_t = [traj.get_start_time() for traj in daily]

daily_lengths = pd.DataFrame(daily_lengths, index=daily_t, columns=['length'])

daily_lengths.hvplot(title='Daily trajectory length')

stops = mpd.TrajectoryStopDetector(traj).get_stop_segments(min_duration=timedelta(seconds=60), max_diameter=100)

    ---------------------------------------------------------------------------

    TypeError                                 Traceback (most recent call last)

![output_6_1](https://user-images.githubusercontent.com/178003/136837828-7e33ee95-99a4-4ceb-b414-f26ddb4051a7.png)
![output_4_1](https://user-images.githubusercontent.com/178003/136837832-2fa3cd33-ac43-43b3-a0b4-3411f83b84f4.png)
    /tmp/ipykernel_235/1649748576.py in <module>
    ----> 1 stops = mpd.TrajectoryStopDetector(traj).get_stop_segments(min_duration=timedelta(seconds=60), max_diameter=100)
    

    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_stop_detector.py in get_stop_segments(self, max_diameter, min_duration)
        113         >>> mpd.TrajectoryStopDetector(traj).get_stop_segments(min_duration=timedelta(seconds=60), max_diameter=100)
        114         """
    --> 115         stop_time_ranges = self.get_stop_time_ranges(max_diameter, min_duration)
        116         return TrajectoryCollection(convert_time_ranges_to_segments(self.traj, stop_time_ranges))
        117 


    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_stop_detector.py in get_stop_time_ranges(self, max_diameter, min_duration)
         41         """
         42         if isinstance(self.traj, Trajectory):
    ---> 43             return self._process_traj(self.traj, max_diameter, min_duration)
         44         elif isinstance(self.traj, TrajectoryCollection):
         45             return self._process_traj_collection(max_diameter, min_duration)


    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_stop_detector.py in _process_traj(self, traj, max_diameter, min_duration)
         80                 segment_begin = segment_times[0]
         81                 if not is_stopped and previously_stopped:
    ---> 82                     if segment_end - segment_begin >= min_duration:  # detected end of a stop
         83                         detected_stops.append(TemporalRangeWithTrajId(segment_begin, segment_end, traj.id))
         84                         segment_geoms = []


    TypeError: '>=' not supported between instances of 'int' and 'datetime.timedelta'

split = mpd.StopSplitter(traj).split(min_duration=timedelta(seconds=60), max_diameter=100)

    ---------------------------------------------------------------------------

    TypeError                                 Traceback (most recent call last)

    /tmp/ipykernel_235/971365991.py in <module>
    ----> 1 split = mpd.StopSplitter(traj).split(min_duration=timedelta(seconds=60), max_diameter=100)
    

    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_splitter.py in split(self, **kwargs)
         41         """
         42         if isinstance(self.traj, Trajectory):
    ---> 43             return self._split_traj(self.traj, **kwargs)
         44         elif isinstance(self.traj, TrajectoryCollection):
         45             return self._split_traj_collection(**kwargs)


    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_splitter.py in _split_traj(self, traj, max_diameter, min_duration, min_length)
        175     def _split_traj(self, traj, max_diameter, min_duration, min_length=0):
        176         stop_detector = TrajectoryStopDetector(traj)
    --> 177         stop_time_ranges = stop_detector.get_stop_time_ranges(max_diameter, min_duration)
        178         between_stops = self.get_time_ranges_between_stops(traj, stop_time_ranges)
        179         result = convert_time_ranges_to_segments(traj, between_stops)


    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_stop_detector.py in get_stop_time_ranges(self, max_diameter, min_duration)
         41         """
         42         if isinstance(self.traj, Trajectory):
    ---> 43             return self._process_traj(self.traj, max_diameter, min_duration)
         44         elif isinstance(self.traj, TrajectoryCollection):
         45             return self._process_traj_collection(max_diameter, min_duration)


    /opt/conda/lib/python3.9/site-packages/movingpandas/trajectory_stop_detector.py in _process_traj(self, traj, max_diameter, min_duration)
         80                 segment_begin = segment_times[0]
         81                 if not is_stopped and previously_stopped:
    ---> 82                     if segment_end - segment_begin >= min_duration:  # detected end of a stop
         83                         detected_stops.append(TemporalRangeWithTrajId(segment_begin, segment_end, traj.id))
         84                         segment_geoms = []


    TypeError: '>=' not supported between instances of 'int' and 'datetime.timedelta'

---

In terms of the data, the table schema looks like this:

                                              Table "owntracks.event"
     Column      |            Type             | Collation | Nullable |                   Default                   
-----------------+-----------------------------+-----------+----------+---------------------------------------------
 id              | integer                     |           | not null | nextval('owntracks.event_id_seq'::regclass)
 geom            | geometry(Point,4326)        |           |          | 
 battery         | integer                     |           | not null | 
 velocity        | double precision            |           |          | 
 altitude        | double precision            |           | not null | 
 course          | double precision            |           |          | 
 device          | character varying(2)        |           | not null | 
 insert_datetime | timestamp without time zone |           | not null | now()
 event_datetime  | timestamp without time zone |           |          | 
 trigger         | character varying(1)        |           |          | 
 battery_status  | integer                     |           |          | 
 in_regions      | text                        |           |          | 
 ssid            | text                        |           |          | 
 bssid           | text                        |           |          | 
 topic           | text                        |           | not null | 'none'::text
 osm_road_id     | integer                     |           |          | 
 has_road        | boolean                     |           | not null | false
Indexes:
    "osm__geom_idx" gist (geom)
    "owntracks_event_geom_idx" gist (geom)
Triggers:
    nearest_road_to_event_trigger BEFORE INSERT OR UPDATE ON owntracks.event FOR EACH ROW EXECUTE FUNCTION nearest_road_to_event_trigger()

[Ali-Ozturk]

I think the input DataFrame may be missing the required DateTimeIndex. Can you double-check if you did to_datetime and set_index, as shown in the tutorials?

gdf = read_file('../data/geolife_small.gpkg')
gdf['t'] = pd.to_datetime(gdf['t'])
gdf = gdf.set_index('t')

Hello Anitagraser,

This has solved my issues thank you!

[anitagraser]

I think the input DataFrame may be missing the required DateTimeIndex. Can you double-check if you did to_datetime and set_index, as shown in the tutorials?

gdf = read_file('../data/geolife_small.gpkg')
gdf['t'] = pd.to_datetime(gdf['t'])
gdf = gdf.set_index('t')