TimestampedGeoJson duration parameter causes polygons to disappear

Hi all - I’m having trouble modifying a code snippet from the second TimestampedGeoJson example in the Plugins example notebook.

import folium
from folium.plugins import TimestampedGeoJson

m = folium.Map(location=[52.467697, -2.548828], zoom_start=6)

polygon = {
    'type': 'Feature',
    'geometry': {
        'type': 'MultiPolygon',
        'coordinates': [((
             (-2.548828, 51.467697),
             (-0.087891, 51.536086),
             (-1.516113, 53.800651),
             (-6.240234, 53.383328),
        ),)],
    },
    'properties': {
        'style': {
            'color': 'blue',
        },
        'times': ['2015-07-22T00:00:00', '2015-08-22T00:00:00', '2015-09-22T00:00:00']
    }
}

TimestampedGeoJson(
    {'type': 'FeatureCollection', 'features': [polygon]},
    period='P1M',
    duration='P1M',
    auto_play=False,
    loop=False,
    loop_button=True,
    date_options='YYYY/MM/DD',
).add_to(m)
    
m

The duration parameter is described as the “period of time which the features will be shown on the map after their time has passed. If None, all previous times will be shown.”

I expect this geometry to be shown on the map for all three time periods, but instead I see it disappear after the first time period.

I’m using folium version 0.6.0 without an ad-blocker. This happens in both Jupyter and html export. The duration parameter was introduced in #894.

[andy23512]

According to the corresponding document of leaflet.js, ( https://github.com/socib/Leaflet.TimeDimension/tree/520cb80f645112e242c5160cb44b7d5f2cae380d#ltimedimensionlayergeojson )

coordTimes, times or linestringTimestamps: array of times that can be associated with a geometry (datestrings or ms). In the case of a LineString, it must have as many items as coordinates in the LineString.

That means if one want to show the polygon at those 6 timestamps, the length of geometry coordinate list should be 6, in order to specify the polygon to be shown at corresponding timestamp.

In you case, you want to show the same polygon (polygon1) at those 6 timestamps. You can add * 6 after the coordinate list to make copies.

So the code that meet your expectation would be:

import folium
from folium.plugins import TimestampedGeoJson

m = folium.Map(location=[52.467697, -2.548828], zoom_start=6)

polygon_1 = {
    'type': 'Feature',
    'geometry': {
        'type': 'MultiPolygon',
        'coordinates': [((
             (-2.548828, 51.467697),
             (-0.087891, 51.536086),
             (-1.516113, 53.800651),
             (-6.240234, 53.383328),
        ),)] * 6, # duplication for matching 6 timestamps
    },
    'properties': {
        'style': {
            'color': 'blue',
        },
        'times': ['2015-07-22T00:00:00', '2015-08-22T00:00:00',
                  '2015-09-22T00:00:00', '2015-10-22T00:00:00',
                  '2015-11-22T00:00:00', '2015-12-22T00:00:00']
    }
}

polygon_2 = {
    'type': 'Feature',
    'geometry': {
        'type': 'MultiPolygon',
        'coordinates': [((
             (-3.548828, 50.467697),
             (-1.087891, 50.536086),
             (-2.516113, 52.800651),
             (-7.240234, 52.383328),
        ),)] * 2, # duplication for matching 2 timestamps
    },
    'properties': {
        'style': {
            'color': 'yellow',
        },
        'times': ['2015-07-22T00:00:00', '2015-08-22T00:00:00']
    }
}

TimestampedGeoJson(
    {'type': 'FeatureCollection', 'features': [polygon_1, polygon_2]},
    period='P1M',
    duration='P1M',
    auto_play=False,
    loop=False,
    loop_button=True,
    date_options='YYYY/MM/DD',
).add_to(m)
    
m

Hope that helps.

[Celtics33]

how do you read a file of multipolygons from a geodataframe?