def get_closest_stations(self, lon, lat, nn=1):
"""
:param lon: longitude (degree)
:param lat: latitude (degrees)
:param nn: number of closest stations to fetch
:return: A tuple containing a list of closest 'network.station' names and a list of distances
(in ascending order) in kms
"""
assert nn > 0, 'nn must be > 0'
xyz = rtp2xyz(np.array([self._earth_radius]),
np.array([np.radians(90 - lat)]),
np.array([np.radians(lon)]))
d, l = self._tree.query(xyz, nn)
if isinstance(l, int):
l = [l]
if (len(d.shape)==1):
d = np.expand_dims(d, axis=0)
l = l[l<len(self.unique_coordinates)]
if isinstance(l, int):
l = [l]
return (list(self._key_list[l]), d[0, :len(l)])
def __init__(self,
asdf_source,
logger=None,
single_item_read_limit_in_mb=1024):
"""
Initializer for FederatedASDFDataSet.
:param asdf_source: Path to a text file containing a list of ASDF files. \
Entries can be commented out with '#'
:param logger: logger instance
"""
self.logger = logger
self.asdf_source = asdf_source
self._unique_coordinates = None
self._earth_radius = 6371 # km
# Instantiate implementation class
self.fds = _FederatedASDFDataSetImpl(
asdf_source,
logger=logger,
single_item_read_limit_in_mb=single_item_read_limit_in_mb)
# Populate coordinates
self._unique_coordinates = defaultdict(list)
rtps_dict = defaultdict()
for ds_dict in self.fds.asdf_station_coordinates:
for key in list(ds_dict.keys()):
self._unique_coordinates[key] = [
ds_dict[key][0], ds_dict[key][1]
]
rtps_dict[key] = [
self._earth_radius,
np.radians(90 - ds_dict[key][1]),
np.radians(ds_dict[key][0])
]
# end for
# end for
rtps_list = []
for k in list(rtps_dict.keys()):
rtps_list.append(rtps_dict[k])
# end for
rtps = np.array(rtps_list)
xyzs = rtp2xyz(rtps[:, 0], rtps[:, 1], rtps[:, 2])
self._tree = cKDTree(xyzs)
self._key_list = np.array(list(rtps_dict.keys()))
def __init__(self,
asdf_source,
variant='db',
use_json_db=False,
logger=None):
"""
:param asdf_source: path to a text file containing a list of ASDF files:
Entries can be commented out with '#'
:param variant: can be either 'mem' or 'db'
:param use_json_db: whether to use json db if available. Has no effect if variant is 'db'
:param logger: logger instance
"""
self.variant = variant
self.use_json_db = use_json_db
self.logger = logger
self.asdf_source = asdf_source
self._unique_coordinates = None
self._earth_radius = 6371 #km
if (self.variant == 'mem'):
if (HAS_RTREE):
self.fds = FederatedASDFDataSetMemVariant(
asdf_source, use_json_db, logger)
else:
raise Exception(
"'mem' variant cannot be used, because package rtree is missing"
)
# end if
elif (self.variant == 'db'):
self.fds = FederatedASDFDataSetDBVariant(asdf_source, logger)
else:
raise Exception("Invalid variant: must be 'mem' or 'db'")
# end if
# Populate coordinates
self._unique_coordinates = defaultdict(list)
rtps_dict = defaultdict()
for ds_dict in self.fds.asdf_station_coordinates:
for key in ds_dict.keys():
self._unique_coordinates[key] = [
ds_dict[key][0], ds_dict[key][1]
]
rtps_dict[key] = [
self._earth_radius,
np.radians(90 - ds_dict[key][1]),
np.radians(ds_dict[key][0])
]
# end for
# end for
rtps_list = []
for k in rtps_dict.keys():
rtps_list.append(rtps_dict[k])
# end for
rtps = np.array(rtps_list)
xyzs = rtp2xyz(rtps[:, 0], rtps[:, 1], rtps[:, 2])
self._tree = cKDTree(xyzs)
self._key_list = np.array(rtps_dict.keys())