# Copyright 2018-2022 Streamlit Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """A wrapper for simple PyDeck scatter charts.""" import copy import json from typing import Any, Dict from typing import cast import pandas as pd import streamlit import streamlit.elements.deck_gl_json_chart as deck_gl_json_chart from streamlit.errors import StreamlitAPIException from streamlit.proto.DeckGlJsonChart_pb2 import DeckGlJsonChart as DeckGlJsonChartProto class MapMixin: def map(self, data=None, zoom=None, use_container_width=True): """Display a map with points on it. This is a wrapper around st.pydeck_chart to quickly create scatterplot charts on top of a map, with auto-centering and auto-zoom. When using this command, we advise all users to use a personal Mapbox token. This ensures the map tiles used in this chart are more robust. You can do this with the mapbox.token config option. To get a token for yourself, create an account at https://mapbox.com. It's free! (for moderate usage levels). For more info on how to set config options, see https://docs.streamlit.io/library/advanced-features/configuration#set-configuration-options Parameters ---------- data : pandas.DataFrame, pandas.Styler, numpy.ndarray, Iterable, dict, or None The data to be plotted. Must have columns called 'lat', 'lon', 'latitude', or 'longitude'. zoom : int Zoom level as specified in https://wiki.openstreetmap.org/wiki/Zoom_levels Example ------- >>> import streamlit as st >>> import pandas as pd >>> import numpy as np >>> >>> df = pd.DataFrame( ... np.random.randn(1000, 2) / [50, 50] + [37.76, -122.4], ... columns=['lat', 'lon']) >>> >>> st.map(df) .. output:: https://share.streamlit.io/streamlit/docs/main/python/api-examples-source/charts.map.py height: 650px """ map_proto = DeckGlJsonChartProto() map_proto.json = to_deckgl_json(data, zoom) map_proto.use_container_width = use_container_width return self.dg._enqueue("deck_gl_json_chart", map_proto) @property def dg(self) -> "streamlit.delta_generator.DeltaGenerator": """Get our DeltaGenerator.""" return cast("streamlit.delta_generator.DeltaGenerator", self) # Map used as the basis for st.map. _DEFAULT_MAP = dict(deck_gl_json_chart.EMPTY_MAP) # type: Dict[str, Any] _DEFAULT_MAP["mapStyle"] = "mapbox://styles/mapbox/light-v10" # Other default parameters for st.map. _DEFAULT_COLOR = [200, 30, 0, 160] _DEFAULT_ZOOM_LEVEL = 12 _ZOOM_LEVELS = [ 360, 180, 90, 45, 22.5, 11.25, 5.625, 2.813, 1.406, 0.703, 0.352, 0.176, 0.088, 0.044, 0.022, 0.011, 0.005, 0.003, 0.001, 0.0005, 0.00025, ] def _get_zoom_level(distance): """Get the zoom level for a given distance in degrees. See https://wiki.openstreetmap.org/wiki/Zoom_levels for reference. Parameters ---------- distance : float How many degrees of longitude should fit in the map. Returns ------- int The zoom level, from 0 to 20. """ # For small number of points the default zoom level will be used. if distance < _ZOOM_LEVELS[-1]: return _DEFAULT_ZOOM_LEVEL for i in range(len(_ZOOM_LEVELS) - 1): if _ZOOM_LEVELS[i + 1] < distance <= _ZOOM_LEVELS[i]: return i def to_deckgl_json(data, zoom): if data is None or data.empty: return json.dumps(_DEFAULT_MAP) if "lat" in data: lat = "lat" elif "latitude" in data: lat = "latitude" else: raise StreamlitAPIException( 'Map data must contain a column named "latitude" or "lat".' ) if "lon" in data: lon = "lon" elif "longitude" in data: lon = "longitude" else: raise StreamlitAPIException( 'Map data must contain a column called "longitude" or "lon".' ) if data[lon].isnull().values.any() or data[lat].isnull().values.any(): raise StreamlitAPIException("Latitude and longitude data must be numeric.") data = pd.DataFrame(data) min_lat = data[lat].min() max_lat = data[lat].max() min_lon = data[lon].min() max_lon = data[lon].max() center_lat = (max_lat + min_lat) / 2.0 center_lon = (max_lon + min_lon) / 2.0 range_lon = abs(max_lon - min_lon) range_lat = abs(max_lat - min_lat) if zoom == None: if range_lon > range_lat: longitude_distance = range_lon else: longitude_distance = range_lat zoom = _get_zoom_level(longitude_distance) # "+1" because itertuples includes the row index. lon_col_index = data.columns.get_loc(lon) + 1 lat_col_index = data.columns.get_loc(lat) + 1 final_data = [] for row in data.itertuples(): final_data.append( {"lon": float(row[lon_col_index]), "lat": float(row[lat_col_index])} ) default = copy.deepcopy(_DEFAULT_MAP) default["initialViewState"]["latitude"] = center_lat default["initialViewState"]["longitude"] = center_lon default["initialViewState"]["zoom"] = zoom default["layers"] = [ { "@@type": "ScatterplotLayer", "getPosition": "@@=[lon, lat]", "getRadius": 10, "radiusScale": 10, "radiusMinPixels": 3, "getFillColor": _DEFAULT_COLOR, "data": final_data, } ] return json.dumps(default)