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"""Tools for generating maps from a text search."""
import geopy as gp
import numpy as np
import matplotlib.pyplot as plt
import warnings
from .tile import howmany, bounds2raster, bounds2img, _sm2ll, _calculate_zoom
from .plotting import INTERPOLATION, ZOOM, add_attribution
from . import providers
from xyzservices import TileProvider
# Set user ID for Nominatim
_val = np.random.randint(1000000)
_default_user_agent = f"contextily_user_{_val}"
class Place(object):
"""Geocode a place by name and get its map.
This allows you to search for a name (e.g., city, street, country) and
grab map and location data from the internet.
Parameters
----------
search : string
The location to be searched.
zoom : int or None
[Optional. Default: None]
The level of detail to include in the map. Higher levels mean more
tiles and thus longer download time. If None, the zoom level will be
automatically determined.
path : str or None
[Optional. Default: None]
Path to a raster file that will be created after getting the place map.
If None, no raster file will be downloaded.
zoom_adjust : int or None
[Optional. Default: None]
The amount to adjust a chosen zoom level if it is chosen automatically.
source : xyzservices.providers object or str
[Optional. Default: OpenStreetMap Humanitarian web tiles]
The tile source: web tile provider or path to local file. The web tile
provider can be in the form of a :class:`xyzservices.TileProvider` object or a
URL. The placeholders for the XYZ in the URL need to be `{x}`, `{y}`,
`{z}`, respectively. For local file paths, the file is read with
`rasterio` and all bands are loaded into the basemap.
IMPORTANT: tiles are assumed to be in the Spherical Mercator
projection (EPSG:3857), unless the `crs` keyword is specified.
geocoder : geopy.geocoders
[Optional. Default: geopy.geocoders.Nominatim()] Geocoder method to process `search`
Attributes
----------
geocode : geopy object
The result of calling ``geopy.geocoders.Nominatim`` with ``search`` as input.
s : float
The southern bbox edge.
n : float
The northern bbox edge.
e : float
The eastern bbox edge.
w : float
The western bbox edge.
im : ndarray
The image corresponding to the map of ``search``.
bbox : list
The bounding box of the returned image, expressed in lon/lat, with the
following order: [minX, minY, maxX, maxY]
bbox_map : tuple
The bounding box of the returned image, expressed in Web Mercator, with the
following order: [minX, minY, maxX, maxY]
"""
def __init__(
self,
search,
zoom=None,
path=None,
zoom_adjust=None,
source=None,
geocoder=gp.geocoders.Nominatim(user_agent=_default_user_agent),
):
self.path = path
if source is None:
source = providers.OpenStreetMap.HOT
self.source = source
self.zoom_adjust = zoom_adjust
# Get geocoded values
resp = geocoder.geocode(search)
bbox = np.array([float(ii) for ii in resp.raw["boundingbox"]])
if "display_name" in resp.raw.keys():
place = resp.raw["display_name"]
elif "address" in resp.raw.keys():
place = resp.raw["address"]
else:
place = search
self.place = place
self.search = search
self.s, self.n, self.w, self.e = bbox
self.bbox = [self.w, self.s, self.e, self.n] # So bbox is standard
self.latitude = resp.latitude
self.longitude = resp.longitude
self.geocode = resp
# Get map params
self.zoom = (
_calculate_zoom(self.w, self.s, self.e, self.n) if zoom is None else zoom
)
self.zoom = int(self.zoom)
if self.zoom_adjust is not None:
self.zoom += zoom_adjust
self.n_tiles = howmany(self.w, self.s, self.e, self.n, self.zoom, verbose=False)
# Get the map
self._get_map()
def _get_map(self):
kwargs = {"ll": True}
if self.source is not None:
kwargs["source"] = self.source
try:
if isinstance(self.path, str):
im, bbox = bounds2raster(
self.w, self.s, self.e, self.n, self.path, zoom=self.zoom, **kwargs
)
else:
im, bbox = bounds2img(
self.w, self.s, self.e, self.n, self.zoom, **kwargs
)
except Exception as err:
raise ValueError(
"Could not retrieve map with parameters: {}, {}, {}, {}, zoom={}\n{}\nError: {}".format(
self.w, self.s, self.e, self.n, self.zoom, kwargs, err
)
)
self.im = im
self.bbox_map = bbox
return im, bbox
def plot(self, ax=None, zoom=ZOOM, interpolation=INTERPOLATION, attribution=None):
"""
Plot a `Place` object
...
Parameters
----------
ax : AxesSubplot
Matplotlib axis with `x_lim` and `y_lim` set in Web
Mercator (EPSG=3857). If not provided, a new
12x12 figure will be set and the name of the place
will be added as title
zoom : int/'auto'
[Optional. Default='auto'] Level of detail for the
basemap. If 'auto', if calculates it automatically.
Ignored if `source` is a local file.
interpolation : str
[Optional. Default='bilinear'] Interpolation
algorithm to be passed to `imshow`. See
`matplotlib.pyplot.imshow` for further details.
attribution : str
[Optional. Defaults to attribution specified by the source of the map tiles]
Text to be added at the bottom of the axis. This
defaults to the attribution of the provider specified
in `source` if available. Specify False to not
automatically add an attribution, or a string to pass
a custom attribution.
Returns
-------
ax : AxesSubplot
Matplotlib axis with `x_lim` and `y_lim` set in Web
Mercator (EPSG=3857) containing the basemap
Examples
--------
>>> lvl = cx.Place('Liverpool')
>>> lvl.plot()
"""
im = self.im
bbox = self.bbox_map
title = None
axisoff = False
if ax is None:
fig, ax = plt.subplots(figsize=(12, 12))
title = self.place
axisoff = True
ax.imshow(im, extent=bbox, interpolation=interpolation)
ax.set(xlabel="X", ylabel="Y")
if isinstance(self.source, (dict, TileProvider)) and attribution is None:
attribution = self.source.get("attribution")
if attribution:
add_attribution(ax, attribution)
if title is not None:
ax.set(title=title)
if axisoff:
ax.set_axis_off()
return ax
def __repr__(self):
s = "Place : {} | n_tiles: {} | zoom : {} | im : {}".format(
self.place, self.n_tiles, self.zoom, self.im.shape[:2]
)
return s
def plot_map(
place, bbox=None, title=None, ax=None, axis_off=True, latlon=True, attribution=None
):
"""Plot a map of the given place.
Parameters
----------
place : instance of Place or ndarray
The map to plot. If an ndarray, this must be an image corresponding
to a map. If an instance of ``Place``, the extent of the image and name
will be inferred from the bounding box.
ax : instance of matplotlib Axes object or None
The axis on which to plot. If None, one will be created.
axis_off : bool
Whether to turn off the axis border and ticks before plotting.
attribution : str
[Optional. Default to standard `ATTRIBUTION`] Text to be added at the
bottom of the axis.
Returns
-------
ax : instance of matplotlib Axes object or None
The axis on the map is plotted.
"""
warnings.warn(
(
"The method `plot_map` is deprecated and will be removed from the"
" library in future versions. Please use either `add_basemap` or"
" the internal method `Place.plot`"
),
DeprecationWarning,
)
if not isinstance(place, Place):
im = place
bbox = bbox
title = title
else:
im = place.im
if bbox is None:
bbox = place.bbox_map
if latlon is True:
# Convert w, s, e, n into lon/lat
w, e, s, n = bbox
w, s = _sm2ll(w, s)
e, n = _sm2ll(e, n)
bbox = [w, e, s, n]
title = place.place if title is None else title
if ax is None:
fig, ax = plt.subplots(figsize=(15, 15))
ax.imshow(im, extent=bbox)
ax.set(xlabel="X", ylabel="Y")
if title is not None:
ax.set(title=title)
if attribution:
add_attribution(ax, attribution)
if axis_off is True:
ax.set_axis_off()
return ax
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