def certain_timezone_at(self, *, lng: float, lat: float) -> Optional[str]:
"""checks in which timezone polygon the point is certainly included in
.. note:: this is only meaningful when you use timezone data WITHOUT oceans!
Otherwise some timezone will always be matched, since ocean timezones span the whole globe.
-> useless to actually test all polygons.
.. note:: this is much slower than 'timezone_at'!
:param lng: longitude of the point in degree
:param lat: latitude in degree
:return: the timezone name of the polygon the point is included in or None
"""
lng, lat = rectify_coordinates(lng, lat)
shortcut_id_x, shortcut_id_y = coord2shortcut(lng, lat)
timezone = self._get_unique_zone(shortcut_id_x, shortcut_id_y)
if timezone is not None: # found perfect and fast match
return timezone
possible_polygons = self.polygon_ids_of_shortcut(
shortcut_id_x, shortcut_id_y)
# x = longitude y = latitude both converted to 8byte int
x = coord2int(lng)
y = coord2int(lat)
# check if the point is actually included in one of the polygons
for polygon_nr in possible_polygons:
# get boundaries
getattr(self, POLY_MAX_VALUES).seek(4 * NR_BYTES_I * polygon_nr)
boundaries = self._fromfile(
getattr(self, POLY_MAX_VALUES),
dtype=DTYPE_FORMAT_SIGNED_I_NUMPY,
count=4,
)
if not (x > boundaries[0] or x < boundaries[1] or y > boundaries[2]
or y < boundaries[3]):
outside_all_holes = True
# when the point is within a hole of the polygon this timezone doesn't need to be checked
for hole_coordinates in self._holes_of_poly(polygon_nr):
if inside_polygon(x, y, hole_coordinates):
outside_all_holes = False
break
if outside_all_holes:
if inside_polygon(x, y,
self.coords_of(polygon_nr=polygon_nr)):
return getattr(self,
TIMEZONE_NAMES)[self.id_of(polygon_nr)]
return None # no polygon has been matched
def certain_timezone_at(self, *, lng: float, lat: float) -> Optional[str]:
""" looks up in which polygon the point certainly is included in
.. note:: this is much slower than 'timezone_at'!
:param lng: longitude of the point in degree
:param lat: latitude in degree
:return: the timezone name of the polygon the point is included in or None
"""
lng, lat = rectify_coordinates(lng, lat)
shortcut_id_x, shortcut_id_y = coord2shortcut(lng, lat)
possible_polygons = self.polygon_ids_of_shortcut(
shortcut_id_x, shortcut_id_y)
# x = longitude y = latitude both converted to 8byte int
x = coord2int(lng)
y = coord2int(lat)
# check if the point is actually included in one of the polygons
for polygon_nr in possible_polygons:
# get boundaries
getattr(self, POLY_MAX_VALUES).seek(4 * NR_BYTES_I * polygon_nr)
boundaries = self._fromfile(getattr(self, POLY_MAX_VALUES),
dtype=DTYPE_FORMAT_SIGNED_I_NUMPY,
count=4)
if not (x > boundaries[0] or x < boundaries[1] or y > boundaries[2]
or y < boundaries[3]):
outside_all_holes = True
# when the point is within a hole of the polygon this timezone doesn't need to be checked
for hole_coordinates in self._holes_of_poly(polygon_nr):
if inside_polygon(x, y, hole_coordinates):
outside_all_holes = False
break
if outside_all_holes:
if inside_polygon(x, y,
self.coords_of(polygon_nr=polygon_nr)):
return getattr(self,
TIMEZONE_NAMES)[self.id_of(polygon_nr)]
return None # no polygon has been matched
def certain_timezone_at(self, *, lng, lat):
"""
this function looks up in which polygon the point certainly is included
this is much slower than 'timezone_at'!
:param lng: longitude of the point in degree
:param lat: latitude in degree
:return: the timezone name of the polygon the point is included in or None
"""
lng, lat = rectify_coordinates(lng, lat)
shortcut_id_x, shortcut_id_y = coord2shortcut(lng, lat)
possible_polygons = self.polygon_ids_of_shortcut(shortcut_id_x, shortcut_id_y)
# x = longitude y = latitude both converted to 8byte int
x = coord2int(lng)
y = coord2int(lat)
# check if the point is actually included in one of the polygons
for polygon_nr in possible_polygons:
# get boundaries
self.poly_max_values.seek(4 * NR_BYTES_I * polygon_nr)
boundaries = self.fromfile(self.poly_max_values, dtype=DTYPE_FORMAT_SIGNED_I_NUMPY, count=4)
if not (x > boundaries[0] or x < boundaries[1] or y > boundaries[2] or y < boundaries[3]):
outside_all_holes = True
# when the point is within a hole of the polygon this timezone doesn't need to be checked
for hole_coordinates in self._holes_of_line(polygon_nr):
if inside_polygon(x, y, hole_coordinates):
outside_all_holes = False
break
if outside_all_holes:
if inside_polygon(x, y, self.coords_of(line=polygon_nr)):
return self.timezone_names[self.id_of(polygon_nr)]
# no polygon has been matched
return None
def timezone_at(self, *, lng: float, lat: float) -> Optional[str]:
""" looks up in which timezone the given coordinate is possibly included in
to speed things up there are shortcuts being used (stored in a binary file)
especially for large polygons it is expensive to check if a point is really included,
so certain simplifications are made and even when you get a hit the point might actually
not be inside the polygon (for example when there is only one timezone nearby)
if you want to make sure a point is really inside a timezone use ``certain_timezone_at()``
:param lng: longitude of the point in degree (-180.0 to 180.0)
:param lat: latitude in degree (90.0 to -90.0)
:return: the timezone name of a matching polygon or None
"""
lng, lat = rectify_coordinates(lng, lat)
shortcut_id_x, shortcut_id_y = coord2shortcut(lng, lat)
getattr(self, SHORTCUTS_UNIQUE_ID).seek(
(NR_LAT_SHORTCUTS * NR_BYTES_H * shortcut_id_x +
NR_BYTES_H * shortcut_id_y))
try:
# if there is just one possible zone in this shortcut instantly return its name
return getattr(self, TIMEZONE_NAMES)[unpack(
DTYPE_FORMAT_H,
getattr(self, SHORTCUTS_UNIQUE_ID).read(NR_BYTES_H))[0]]
except IndexError:
possible_polygons = self.polygon_ids_of_shortcut(
shortcut_id_x, shortcut_id_y)
nr_possible_polygons = len(possible_polygons)
if nr_possible_polygons == 0:
return None
if nr_possible_polygons == 1:
# there is only one polygon in that area. return its timezone name without further checks
return getattr(self, TIMEZONE_NAMES)[self.id_of(
possible_polygons[0])]
# create a list of all the timezone ids of all possible polygons
ids = self.id_list(possible_polygons, nr_possible_polygons)
# x = longitude y = latitude both converted to 8byte int
x = coord2int(lng)
y = coord2int(lat)
# check until the point is included in one of the possible polygons
for i in range(nr_possible_polygons):
# when including the current polygon only polygons from the same zone remain,
same_element = all_the_same(pointer=i,
length=nr_possible_polygons,
id_list=ids)
if same_element != -1:
# return the name of that zone
return getattr(self, TIMEZONE_NAMES)[same_element]
polygon_nr = possible_polygons[i]
# get the boundaries of the polygon = (lng_max, lng_min, lat_max, lat_min)
getattr(self,
POLY_MAX_VALUES).seek(4 * NR_BYTES_I * polygon_nr)
boundaries = self._fromfile(getattr(self, POLY_MAX_VALUES),
dtype=DTYPE_FORMAT_SIGNED_I_NUMPY,
count=4)
# only run the expensive algorithm if the point is withing the boundaries
if not (x > boundaries[0] or x < boundaries[1]
or y > boundaries[2] or y < boundaries[3]):
outside_all_holes = True
# when the point is within a hole of the polygon, this timezone must not be returned
for hole_coordinates in self._holes_of_poly(polygon_nr):
if inside_polygon(x, y, hole_coordinates):
outside_all_holes = False
break
if outside_all_holes:
if inside_polygon(
x, y, self.coords_of(polygon_nr=polygon_nr)):
# the point is included in this polygon. return its timezone name without further checks
return getattr(self, TIMEZONE_NAMES)[ids[i]]
# the timezone name of the last polygon should always be returned
# if no other polygon has been matched beforehand.
raise ValueError(
'BUG: this statement should never be reached. Please open up an issue on Github!'
)
def timezone_at(self, *, lng: float, lat: float) -> str:
"""computes in which ocean OR land timezone a point is included in
Especially for large polygons it is expensive to check if a point is really included.
To speed things up there are "shortcuts" being used (stored in a binary file),
which have been precomputed and store which timezone polygons have to be checked.
In case there is only one possible zone this zone will instantly be returned without actually checking
if the query point is included in this polygon -> speed up
Since ocean timezones span the whole globe, some timezone will always be matched!
:param lng: longitude of the point in degree (-180.0 to 180.0)
:param lat: latitude in degree (90.0 to -90.0)
:return: the timezone name of the matched timezone polygon. possibly "Etc/GMT+-XX" in case of an ocean timezone.
"""
lng, lat = rectify_coordinates(lng, lat)
shortcut_id_x, shortcut_id_y = coord2shortcut(lng, lat)
timezone = self._get_unique_zone(shortcut_id_x, shortcut_id_y)
if timezone is not None: # found perfect and fast match
return timezone
# more thorough testing required:
possible_polygons = self.polygon_ids_of_shortcut(
shortcut_id_x, shortcut_id_y)
nr_possible_polygons = len(possible_polygons)
if nr_possible_polygons == 0:
raise ValueError(
"some timezone polygon should be present (ocean timezones exist everywhere)!"
)
if nr_possible_polygons == 1:
# there is only one polygon in that area. return its timezone name without further checks
return getattr(self,
TIMEZONE_NAMES)[self.id_of(possible_polygons[0])]
# create a list of all the timezone ids of all possible polygons
ids = self.id_list(possible_polygons, nr_possible_polygons)
# x = longitude y = latitude both converted to 8byte int
x = coord2int(lng)
y = coord2int(lat)
# check until the point is included in one of the possible polygons
for i in range(nr_possible_polygons):
# when including the current polygon only polygons from the same zone remain,
same_element = all_the_same(pointer=i,
length=nr_possible_polygons,
id_list=ids)
if same_element != -1:
# return the name of that zone
return getattr(self, TIMEZONE_NAMES)[same_element]
polygon_nr = possible_polygons[i]
# get the boundaries of the polygon = (lng_max, lng_min, lat_max, lat_min)
getattr(self, POLY_MAX_VALUES).seek(4 * NR_BYTES_I * polygon_nr)
boundaries = self._fromfile(
getattr(self, POLY_MAX_VALUES),
dtype=DTYPE_FORMAT_SIGNED_I_NUMPY,
count=4,
)
# only run the expensive algorithm if the point is withing the boundaries
if not (x > boundaries[0] or x < boundaries[1] or y > boundaries[2]
or y < boundaries[3]):
outside_all_holes = True
# when the point is within a hole of the polygon, this timezone must not be returned
for hole_coordinates in self._holes_of_poly(polygon_nr):
if inside_polygon(x, y, hole_coordinates):
outside_all_holes = False
break
if outside_all_holes:
if inside_polygon(x, y,
self.coords_of(polygon_nr=polygon_nr)):
# the point is included in this polygon. return its timezone name without further checks
return getattr(self, TIMEZONE_NAMES)[ids[i]]
# the timezone name of the last polygon should always be returned
# if no other polygon has been matched beforehand.
raise ValueError(
"BUG: this statement should never be reached. Please open up an issue on Github!"
)