def __init__(self, filename):
'''
:param str filename:
Name of the catalogue file in ndk format
'''
self.filename = filename
self.data = GCMTCatalogue()
def read_file(self, start_year=None, end_year=None):
'''
Reads the file
'''
raw_data = getlines(self.filename)
num_lines = len(raw_data)
if ((float(num_lines) / 5.) - float(num_lines // 5)) > 1E-9:
raise IOError('GCMT represented by 5 lines - number in file not'
' a multiple of 5!')
number_gcmts = num_lines // 5
# Pre-allocates list
data_gcmts = [None for i in range(number_gcmts)]
id0 = 0
print('Parsing catalogue ...')
for iloc in range(number_gcmts):
data_gcmts[iloc] = self.read_ndk_event(raw_data, id0)
id0 += 5
print('complete. Contains %s moment tensors' % len(data_gcmts))
if not start_year:
start_year = data_gcmts[0].centroid.date.year
if not end_year:
end_year = data_gcmts[-1].centroid.date.year
return GCMTCatalogue(start_year, end_year, data_gcmts)
def __init__(self):
"""
Initialise the catalogue with an empty data dictionary
"""
self.data = {}
for attribute in self.TOTAL_ATTRIBUTE_LIST:
if attribute in self.FLOAT_ATTRIBUTE_LIST:
self.data[attribute] = np.array([], dtype=float)
elif attribute in self.INT_ATTRIBUTE_LIST:
self.data[attribute] = np.array([], dtype=int)
else:
self.data[attribute] = []
self.number_earthquakes = 0
self.gcmt_catalogue = GCMTCatalogue()
class ParseNDKtoGCMT(object):
'''
Implements the parser to read a file in ndk format to the GCMT catalogue
'''
def __init__(self, filename):
'''
:param str filename:
Name of the catalogue file in ndk format
'''
self.filename = filename
self.data = GCMTCatalogue()
def read_file(self, start_year=None, end_year=None):
'''
Reads the file
'''
raw_data = getlines(self.filename)
num_lines = len(raw_data)
if ((float(num_lines) / 5.) - float(num_lines / 5)) > 1E-9:
raise IOError('GCMT represented by 5 lines - number in file not'
' a multiple of 5!')
self.data.number_gcmts = num_lines / 5
self.data.gcmts = [None] * self.data.number_gcmts #Pre-allocates list
id0 = 0
print 'Parsing catalogue ...'
for iloc in range(0, self.data.number_gcmts):
self.data.gcmts[iloc] = self.read_ndk_event(raw_data, id0)
id0 += 5
print 'complete. Contains %s moment tensors' \
% self.data.number_events()
if not start_year:
self.data.start_year = self.data.gcmts[1].centroid.date.year
if not end_year:
self.data.end_year = self.data.gcmts[-1].centroid.date.year
return self.data
def read_ndk_event(self, raw_data, id0):
'''
Reads a 5-line batch of data into a set of GCMTs
'''
gcmt = GCMTEvent()
# Get hypocentre
ndkstring = raw_data[id0].rstrip('\n')
gcmt.hypocentre = self._read_hypocentre_from_ndk_string(ndkstring)
# GCMT metadata
ndkstring = raw_data[id0 + 1].rstrip('\n')
gcmt = self._get_metadata_from_ndk_string(gcmt, ndkstring)
# Get Centroid
ndkstring = raw_data[id0 + 2].rstrip('\n')
gcmt.centroid = self._read_centroid_from_ndk_string(
ndkstring, gcmt.hypocentre)
# Get Moment Tensor
ndkstring = raw_data[id0 + 3].rstrip('\n')
gcmt.moment_tensor = self._get_moment_tensor_from_ndk_string(ndkstring)
# Get principal axes
ndkstring = raw_data[id0 + 4].rstrip('\n')
gcmt.principal_axes = self._get_principal_axes_from_ndk_string(
ndkstring[3:48], exponent=gcmt.moment_tensor.exponent)
# Get Nodal Planes
gcmt.nodal_planes = self._get_nodal_planes_from_ndk_string(
ndkstring[57:])
# Get Moment and Magnitude
gcmt.moment, gcmt.version, gcmt.magnitude = \
self._get_moment_from_ndk_string(ndkstring,
gcmt.moment_tensor.exponent)
return gcmt
def _read_hypocentre_from_ndk_string(self, linestring):
'''
Reads the hypocentre data from the ndk string to return an
instance of the GCMTHypocentre class
'''
hypo = GCMTHypocentre()
hypo.source = linestring[0:4]
hypo.date = _read_date_from_string(linestring[5:15])
hypo.time = _read_time_from_string(linestring[16:26])
hypo.latitude = float(linestring[27:33])
hypo.longitude = float(linestring[34:41])
hypo.depth = float(linestring[42:47])
magnitudes = map(float, (linestring[48:55]).split(' '))
if magnitudes[0] > 0.:
hypo.m_b = magnitudes[0]
if magnitudes[1] > 0.:
hypo.m_s = magnitudes[1]
hypo.location = linestring[56:]
return hypo
def _get_metadata_from_ndk_string(self, gcmt, ndk_string):
'''
Reads the GCMT metadata from line 2 of the ndk batch
'''
gcmt.identifier = ndk_string[:16]
inversion_data = re.split('[A-Z:]+', ndk_string[17:61])
gcmt.metadata['BODY'] = map(float, inversion_data[1].split())
gcmt.metadata['SURFACE'] = map(float, inversion_data[2].split())
gcmt.metadata['MANTLE'] = map(float, inversion_data[3].split())
further_meta = re.split('[: ]+', ndk_string[62:])
gcmt.metadata['CMT'] = int(further_meta[1])
gcmt.metadata['FUNCTION'] = {
'TYPE': further_meta[2],
'DURATION': float(further_meta[3])
}
return gcmt
def _read_centroid_from_ndk_string(self, ndk_string, hypocentre):
'''
Reads the centroid data from the ndk string to return an
instance of the GCMTCentroid class
:param str ndk_string:
String of data (line 3 of ndk format)
:param hypocentre:
Instance of the GCMTHypocentre class
'''
centroid = GCMTCentroid(hypocentre.date, hypocentre.time)
data = ndk_string[:58].split()
centroid.centroid_type = data[0].rstrip(':')
data = map(float, data[1:])
time_diff = data[0]
if fabs(time_diff) > 1E-6:
centroid._get_centroid_time(time_diff)
centroid.time_error = data[1]
centroid.latitude = data[2]
centroid.latitude_error = data[3]
centroid.longitude = data[4]
centroid.longitude_error = data[5]
centroid.depth = data[6]
centroid.depth_error = data[7]
centroid.depth_type = ndk_string[59:63]
centroid.centroid_id = ndk_string[64:]
return centroid
def _get_moment_tensor_from_ndk_string(self, ndk_string):
'''
Reads the moment tensor from the ndk_string and returns an instance of
the GCMTMomentTensor class.
By default the ndk format uses the Up, South, East (USE) reference
system.
'''
moment_tensor = GCMTMomentTensor('USE')
tensor_data = _read_moment_tensor_from_ndk_string(ndk_string, 'USE')
moment_tensor.tensor = tensor_data[0]
moment_tensor.tensor_sigma = tensor_data[1]
moment_tensor.exponent = tensor_data[2]
return moment_tensor
def _get_principal_axes_from_ndk_string(self, ndk_string, exponent):
'''
Gets the principal axes from the ndk string and returns an instance
of the GCMTPrincipalAxes class
'''
axes = GCMTPrincipalAxes()
# The principal axes is defined in characters 3:48 of the 5th line
exponent = 10.**exponent
axes.t_axis = {
'eigenvalue': exponent * float(ndk_string[0:8]),
'plunge': float(ndk_string[8:11]),
'azimuth': float(ndk_string[11:15])
}
axes.b_axis = {
'eigenvalue': exponent * float(ndk_string[15:23]),
'plunge': float(ndk_string[23:26]),
'azimuth': float(ndk_string[26:30])
}
axes.p_axis = {
'eigenvalue': exponent * float(ndk_string[30:38]),
'plunge': float(ndk_string[38:41]),
'azimuth': float(ndk_string[41:])
}
return axes
def _get_nodal_planes_from_ndk_string(self, ndk_string):
'''
Reads the nodal plane information (represented by 5th line [57:] of the
tensor representation) and returns an instance of the GCMTNodalPlanes
class
'''
planes = GCMTNodalPlanes()
planes.nodal_plane_1 = {
'strike': float(ndk_string[0:3]),
'dip': float(ndk_string[3:6]),
'rake': float(ndk_string[6:11])
}
planes.nodal_plane_2 = {
'strike': float(ndk_string[11:15]),
'dip': float(ndk_string[15:18]),
'rake': float(ndk_string[18:])
}
return planes
def _get_moment_from_ndk_string(self, ndk_string, exponent):
'''
Gets the moment and the moment magnitude
'''
moment = float(ndk_string[49:56]) * (10.**exponent)
version = ndk_string[:3]
magnitude = utils.moment_magnitude_scalar(moment)
return moment, version, magnitude