Source code for obspy.io.arclink.inventory

# -*- coding: utf-8 -*-
"""
ObsPy implementation for parsing the arclink inventory format
to an Inventory object.

This is a modified version of obspy.io.stationxml and obspy.io.sc3ml.

:author:
    Mathijs Koymans (koymans@knmi.nl), 29.2016 - [Jollyfant@GitHub]
:copyright:
    The ObsPy Development Team (devs@obspy.org)
:license:
    GNU Lesser General Public License, Version 3
    (https://www.gnu.org/copyleft/lesser.html)
"""
import inspect
import math
from pathlib import Path
import re
import warnings

from lxml import etree

import obspy
from obspy.core.util.obspy_types import (ComplexWithUncertainties,
                                         FloatWithUncertaintiesAndUnit)
from obspy.core.inventory import (Azimuth, ClockDrift, Dip,
                                  Distance, Frequency, Latitude,
                                  Longitude, SampleRate)
from obspy.core.inventory import (CoefficientsTypeResponseStage,
                                  FilterCoefficient, FIRResponseStage,
                                  PolesZerosResponseStage,
                                  PolynomialResponseStage)

SOFTWARE_MODULE = "ObsPy %s" % obspy.__version__
SOFTWARE_URI = "http://www.obspy.org"
SCHEMA_VERSION = "1.0"
SCHEMA_NAMESPACE = "http://geofon.gfz-potsdam.de/ns/Inventory/1.0/"


[docs]def _is_inventory_xml(path_or_file_object): """ Simple function checking if the passed object contains a valid arclink XML 1.0 file. Returns True of False. The test is not exhaustive - it only checks the root tag but that should be good enough for most real world use cases. If the schema is used to test for a StationXML file, many real world files are false negatives as they don't adhere to the standard. :param path_or_file_object: File name or file like object. """ if hasattr(path_or_file_object, "tell") and hasattr(path_or_file_object, "seek"): current_position = path_or_file_object.tell() try: if isinstance(path_or_file_object, etree._Element): xmldoc = path_or_file_object else: try: xmldoc = etree.parse(path_or_file_object) except etree.XMLSyntaxError: return False root = xmldoc.getroot() if re.match(r'{http://geofon.gfz-potsdam.de/ns/Inventory/' r'[0-9]*\.?[0-9]+/}', root.tag) is None: return False # Match and convert schema number to a float to have positive # comparisons between, e.g "1" and "1.0". version = float(re.findall(r"\d+\.\d+", root.tag)[0]) if float(version != float(SCHEMA_VERSION)): warnings.warn("The inventory file has version %s, ObsPy can " "deal with version %s. Proceed with caution." % ( root.attrib["version"], SCHEMA_VERSION)) return True finally: # Make sure to reset file pointer position. try: path_or_file_object.seek(current_position, 0) except Exception: pass
[docs]def _ns(tagname): """ Hoisted namespace function used to find elements :param tagname: name of tag to be extracted """ return "{%s}%s" % (SCHEMA_NAMESPACE, tagname)
[docs]def _read_inventory_xml(path_or_file_object, **kwargs): """ Function for reading an Arclink inventory file. :param path_or_file_object: File name or file like object. """ root = etree.parse(path_or_file_object).getroot() created = None sender = "ObsPy Inventory" # Set source to this script source = "Arclink Inventory Import" module = None module_uri = None # Collect all networks from the arcllink inventory networks = [] for net_element in root.findall(_ns("network")): networks.append(_read_network(root, net_element)) return obspy.core.inventory.Inventory(networks=networks, source=source, sender=sender, created=created, module=module, module_uri=module_uri)
[docs]def _attr2obj(element, attribute, convert): """ Reads text from attribute in element :param element: etree element :param attribute: name of attribute to be read :param convert: intrinsic function (e.g. int, str, float) """ try: if element.get(attribute) is None: return None elif element.get(attribute) == '': return None return convert(element.get(attribute)) except Exception: None
[docs]def _tag2obj(element, tag, convert): """ Reads text from tag in element :param element: etree element :param tag: name of tag to be read :param convert: intrinsic function (e.g. int, str, float) """ try: if element.find(tag).text is None: return None return convert(element.find(tag).text) except Exception: None
[docs]def _read_network(inventory_root, net_element): """ Reads the network structure :param inventory_root: base inventory element of document :param net_element: network element to be read :param _ns: namespace """ # Get the network code as attribute (e.g. <network code="GB">) network = obspy.core.inventory.Network(net_element.get("code")) # There is no further information in the attributes of <network> # Start and end date are included as tags network.start_date = _attr2obj(net_element, 'start', obspy.UTCDateTime) network.end_date = _attr2obj(net_element, 'end', obspy.UTCDateTime) network.description = _attr2obj(net_element, 'description', str) # get the restricted_status (boolean) # true is evaluated to 'open'; false to 'closed' # to match stationXML format network.restricted_status = _get_restricted_status(net_element) # Collect the stations stations = [] for sta_element in net_element.findall(_ns("station")): stations.append(_read_station(inventory_root, sta_element)) network.stations = stations return network
[docs]def _get_restricted_status(element): """ get the restricted_status (boolean) true is evaluated to 'open' and false to 'closed' to match stationXML formatting :param element: xmltree element status is extracted from """ restricted_status = _attr2obj(element, "restricted", str) if restricted_status == 'false': return 'open' else: return 'closed'
[docs]def _read_station(inventory_root, sta_element): """ Reads the station structure :param inventory_root: base inventory element of document :param sta_element: station element to be read """ # Read location tags longitude = _attr2obj(sta_element, "longitude", Longitude) latitude = _attr2obj(sta_element, "latitude", Latitude) elevation = _attr2obj(sta_element, "elevation", Distance) station = obspy.core.inventory.Station(code=sta_element.get("code"), latitude=latitude, longitude=longitude, elevation=elevation) station.site = _read_site(sta_element) # There is no relevant info in the base node # Read the start and end date (creation, termination) from tags station.start_date = _attr2obj(sta_element, "start", obspy.UTCDateTime) station.end_date = _attr2obj(sta_element, "end", obspy.UTCDateTime) station.creation_date = _attr2obj(sta_element, "start", obspy.UTCDateTime) station.termination_date = _attr2obj(sta_element, "end", obspy.UTCDateTime) # get the restricted_status (boolean) # true is evaluated to 'open'; false to 'closed' station.restricted_status = _get_restricted_status(sta_element) # Get all the channels, format keeps these in <sensorLocation> tags in the # station element. Individual channels are contained within <stream> tags channels = [] for sen_loc_element in sta_element.findall(_ns("sensorLocation")): for channel in sen_loc_element.findall(_ns("stream")): channels.append(_read_channel(inventory_root, channel)) station.channels = channels return station
[docs]def _read_site(sta_element): """ Reads site information from the station element tags and region from network element In arclinkXML, site information are included as tags in the station_element :param sta_element: station element """ # The region is defined in the parent network element net_element = sta_element.getparent() region = _attr2obj(net_element, "region", str) # The country, place, description are given in the # station element country = _attr2obj(sta_element, "country", str) place = _attr2obj(sta_element, "place", str) description = _attr2obj(sta_element, "description", str) # The name is usually the description name = description return obspy.core.inventory.Site(name=name, description=description, town=place, county=None, region=region, country=country)
[docs]def _read_datalogger(equip_element): """ Reads equipment information from datalogger Some information is not present > to None :param equip_element: element to be parsed """ resource_id = equip_element.get("publicID") description = _attr2obj(equip_element, "description", str) manufacturer = _attr2obj(equip_element, "digitizerManufacturer", str) model = _attr2obj(equip_element, "digitizerModel", str) # A lot of properties are not specified in the ArclinkXML return obspy.core.inventory.Equipment( resource_id=resource_id, type=model, description=description, manufacturer=manufacturer, vendor=None, model=model, serial_number=None, installation_date=None, removal_date=None, calibration_dates=None)
[docs]def _read_sensor(equip_element): """ Reads equipment information from element Some information is not present > to None :param equip_element: element to be parsed """ # try to read some element tags, most are missing anyway resource_id = equip_element.get("publicID") equipment_type = _attr2obj(equip_element, "type", str) description = _attr2obj(equip_element, "description", str) manufacturer = _attr2obj(equip_element, "manufacturer", str) model = _attr2obj(equip_element, "model", str) # A lot of properties are not specified in the ArclinkXML return obspy.core.inventory.Equipment( resource_id=resource_id, type=equipment_type, description=description, manufacturer=manufacturer, vendor=None, model=model, serial_number=None, installation_date=None, removal_date=None, calibration_dates=None)
[docs]def _read_channel(inventory_root, cha_element): """ reads channel element from arclinkXML format :param inventory_root: root of the XML document :param cha_element: channel element to be parsed """ code = cha_element.get("code") # Information is also kept within the parent <sensorLocation> element sen_loc_element = cha_element.getparent() location_code = sen_loc_element.get("code") # get site info from the <sensorLocation> element longitude = _attr2obj(sen_loc_element, "longitude", Longitude) latitude = _attr2obj(sen_loc_element, "latitude", Latitude) elevation = _attr2obj(sen_loc_element, "elevation", Distance) depth = _attr2obj(cha_element, "depth", Distance) channel = obspy.core.inventory.Channel( code=code, location_code=location_code, latitude=latitude, longitude=longitude, elevation=elevation, depth=depth) # obtain the sensorID and link to particular publicID <sensor> element # in the inventory base node sensor_id = cha_element.get("sensor") sensor_element = inventory_root.find(_ns("sensor[@publicID='" + sensor_id + "']")) # obtain the poles and zeros responseID and link to particular # <responsePAZ> publicID element in the inventory base node if sensor_element is not None: response_id = sensor_element.get("response") if response_id is not None: # Fix #2552 resp_type = response_id.replace("#", "/").split("/")[0] if resp_type == 'ResponsePAZ': search = "responsePAZ[@publicID='" + response_id + "']" response_element = inventory_root.find(_ns(search)) elif resp_type == 'ResponsePolynomial': search = "responsePolynomial[@publicID='" + response_id + "']" response_element = inventory_root.find(_ns(search)) else: response_element = None else: response_element = None # obtain the dataloggerID and link to particular <responsePAZ> publicID # element in the inventory base node datalogger_id = cha_element.get("datalogger") search = "datalogger[@publicID='" + datalogger_id + "']" data_log_element = inventory_root.find(_ns(search)) channel.restricted_status = _get_restricted_status(cha_element) # There is no further information in the attributes of <stream> # Start and end date are included as tags instead channel.start_date = _attr2obj(cha_element, "start", obspy.UTCDateTime) channel.end_date = _attr2obj(cha_element, "end", obspy.UTCDateTime) # Determine sample rate (given is a numerator, denominator) # Assuming numerator is # samples and denominator is # seconds numerator = _attr2obj(cha_element, "sampleRateNumerator", int) denominator = _attr2obj(cha_element, "sampleRateDenominator", int) rate = numerator / denominator channel.sample_rate_ratio_number_samples = numerator channel.sample_rate_ratio_number_seconds = denominator channel.sample_rate = _read_float_var(rate, SampleRate) if sensor_element is not None: channel.sensor = _read_sensor(sensor_element) if data_log_element is not None: channel.data_logger = _read_datalogger(data_log_element) temp = _attr2obj(data_log_element, "maxClockDrift", ClockDrift) if channel.sample_rate != 0.0: channel.clock_drift_in_seconds_per_sample = \ _read_float_var(temp / channel.sample_rate, ClockDrift) else: msg = "Clock drift division by sample rate of 0: using sec/sample" warnings.warn(msg) channel.sample_rate = temp channel.azimuth = _attr2obj(cha_element, "azimuth", Azimuth) channel.dip = _attr2obj(cha_element, "dip", Dip) # storage format of channel not supported by StationXML1.1 anymore, keep it # as a foreign tag to be nice if anybody needs to access it channel.extra = {'format': { 'value': _tag2obj(cha_element, _ns("format"), str), 'namespace': SCHEMA_NAMESPACE}} if channel.sample_rate == 0.0: msg = "Something went hopelessly wrong, found sampling-rate of 0!" warnings.warn(msg) # Begin to collect digital/analogue filter chains # This information is stored as an array in the datalogger element response_fir_id = [] response_paz_id = [] if data_log_element is not None: # Find the decimation element with a particular num/denom decim_element = data_log_element.find(_ns( "decimation[@sampleRateDenominator='" + str(int(denominator)) + "'][@sampleRateNumerator='" + str(int(numerator)) + "']")) analogue_filter_chain = _tag2obj(decim_element, _ns("analogueFilterChain"), str) if analogue_filter_chain is not None: response_paz_id = analogue_filter_chain.split(" ") digital_filter_chain = _tag2obj(decim_element, _ns("digitalFilterChain"), str) if digital_filter_chain is not None: response_fir_id = digital_filter_chain.split(" ") channel.response = _read_response(inventory_root, sensor_element, response_element, cha_element, data_log_element, channel.sample_rate, response_fir_id, response_paz_id) return channel
[docs]def _read_instrument_sensitivity(sen_element, cha_element): """ reads the instrument sensitivity (gain) from the sensor and channel element :param sen_element: sensor element to be parsed :param cha_element: channel element to be parsed """ # Read the gain and gain frequency from attributs gain = _attr2obj(cha_element, "gain", float) frequency = _attr2obj(cha_element, "gainFrequency", float) # Get input units and hardcode output units to counts input_units_name = _attr2obj(sen_element, "unit", str) output_units_name = 'COUNTS' sensitivity = obspy.core.inventory.response.InstrumentSensitivity( value=gain, frequency=frequency, input_units=input_units_name, output_units=output_units_name) # assuming these are equal to frequencyStart/frequencyEnd sensitivity.frequency_range_start = _attr2obj(sen_element, "lowFrequency", float) sensitivity.frequency_range_end = _attr2obj(sen_element, "highFrequency", float) return sensitivity
[docs]def _read_response(root, sen_element, resp_element, cha_element, data_log_element, samp_rate, fir, analogue): """ reads response from arclinkXML format :param root: XML document root element :param sen_element: sensor element to be used :param resp_element: response element to be parsed :param cha_element: channel element to be used :param data_log_element: datalogger element to be used :param samp_rate: sample rate of stream :param fir: list of FIR filter chain identifiers :param analogue: list of analogue filter chain identifiers """ response = obspy.core.inventory.response.Response() response.instrument_sensitivity = _read_instrument_sensitivity( sen_element, cha_element) if resp_element is None: return response # The sampling rate is not given per fir filter as in stationXML # We are only given a decimation factor per stage, therefore we are # required to reconstruct the sampling rates at a given stage from # this chain of factors # start with the final sampling_rate after all stages are applied # invert the fir stages to reverse engineer (backwards) the sample rate # during any fir stage samp_rate = float(samp_rate) fir_stage_rates = [] if len(fir): fir = fir[::-1] for fir_id in fir: # get the particular fir stage decimation factor # multiply the decimated sample rate by this factor search = "responseFIR[@publicID='" + fir_id + "']" fir_element = root.find(_ns(search)) if fir_element is None: continue dec_fac = _attr2obj(fir_element, "decimationFactor", int) if dec_fac is not None and int(dec_fac) != 0: samp_rate *= dec_fac fir_stage_rates.append(float(samp_rate)) # Return filter chain to original and also revert the rates fir = fir[::-1] fir_stage_rates = fir_stage_rates[::-1] # Attempt to read stages in the proper order # arclinkXML does not group stages by an ID # We are required to do stage counting ourselves stage = 1 # Get the sensor units, default to M/S sensor_units = _attr2obj(sen_element, "unit", str) if sensor_units is None: msg = "Sensor unit not set, assuming M/S" warnings.warn(msg) sensor_units = "M/S" # Get the first PAZ stage # Input unit: M/S or M/S**2 # Output unit: V if resp_element is not None: paz_response = _read_response_stage(resp_element, samp_rate, stage, sensor_units, 'V') if paz_response is not None: response.response_stages.append(paz_response) stage += 1 # Apply analogue filter stages (if any) # Input unit: V # Output unit: V if len(analogue): for analogue_id in analogue: search = "responsePAZ[@publicID='" + analogue_id + "']" analogue_element = root.find(_ns(search)) if analogue_element is None: msg = ('Analogue responsePAZ not in inventory:' '%s, stopping before stage %i') % (analogue_id, stage) warnings.warn(msg) return response analogue_response = _read_response_stage(analogue_element, samp_rate, stage, 'V', 'V') if analogue_response is not None: response.response_stages.append(analogue_response) stage += 1 # Apply datalogger (digitizer) # Input unit: V # Output unit: COUNTS if data_log_element is not None: coeff_response = _read_response_stage(data_log_element, samp_rate, stage, 'V', 'COUNTS') if coeff_response is not None: response.response_stages.append(coeff_response) stage += 1 # Apply final digital filter stages # Input unit: COUNTS # Output unit: COUNTS for fir_id, rate in zip(fir, fir_stage_rates): search = "responseFIR[@publicID='" + fir_id + "']" stage_element = root.find(_ns(search)) if stage_element is None: msg = ("fir response not in inventory: %s, stopping correction" "before stage %i") % (fir_id, stage) warnings.warn(msg) return response fir_response = _read_response_stage(stage_element, rate, stage, 'COUNTS', 'COUNTS') if fir_response is not None: response.response_stages.append(fir_response) stage += 1 return response
[docs]def _read_response_stage(stage, rate, stage_number, input_units, output_units): """ Private function to read a response stage :param stage: response stage element :param rate: stage sample rate :param stage_number: response stage number :param input_units: input units of stage :param output_units: output units of stage """ elem_type = stage.tag.split("}")[1] stage_sequence_number = stage_number # Obtain the stage gain and frequency # Default to a gain of 0 and frequency of 0 if missing stage_gain = _attr2obj(stage, "gain", float) or 0 stage_gain_frequency = _attr2obj(stage, "gainFrequency", float) or 0.0 name = _attr2obj(stage, "name", str) resource_id = _attr2obj(stage, "publicID", str) # Determine the decimation parameters # This is dependent on the type of stage # Decimation delay/correction need to be normalized if elem_type == "responseFIR": decimation_factor = _attr2obj(stage, "decimationFactor", int) if rate != 0.0: temp = _attr2obj(stage, "delay", float) / rate decimation_delay = _read_float_var(temp, FloatWithUncertaintiesAndUnit, unit=True) temp = _attr2obj(stage, "correction", float) / rate decimation_corr = _read_float_var(temp, FloatWithUncertaintiesAndUnit, unit=True) else: decimation_delay = _read_float_var("inf", FloatWithUncertaintiesAndUnit, unit=True) decimation_corr = _read_float_var("inf", FloatWithUncertaintiesAndUnit, unit=True) decimation_input_sample_rate = \ _read_float_var(rate, Frequency) decimation_offset = int(0) elif elem_type == "datalogger": decimation_factor = int(1) decimation_delay = _read_float_var(0.00, FloatWithUncertaintiesAndUnit, unit=True) decimation_corr = _read_float_var(0.00, FloatWithUncertaintiesAndUnit, unit=True) decimation_input_sample_rate = \ _read_float_var(rate, Frequency) decimation_offset = int(0) elif elem_type == "responsePAZ" or elem_type == "responsePolynomial": decimation_factor = None decimation_delay = None decimation_corr = None decimation_input_sample_rate = None decimation_offset = None else: raise ValueError("Unknown type of response: " + str(elem_type)) # set up list of for this stage arguments kwargs = { "stage_sequence_number": stage_sequence_number, "input_units": str(input_units), "output_units": str(output_units), "input_units_description": None, "output_units_description": None, "resource_id": None, "resource_id2": resource_id, "stage_gain": stage_gain, "stage_gain_frequency": stage_gain_frequency, "name": name, "description": None, "decimation_input_sample_rate": decimation_input_sample_rate, "decimation_factor": decimation_factor, "decimation_offset": decimation_offset, "decimation_delay": decimation_delay, "decimation_correction": decimation_corr } # Different processing for different types of responses # currently supported: # PAZ, COEFF, FIR, Polynomial response is not supported; # could not find example if elem_type == 'responsePAZ': # read normalization params normalization_freq = _attr2obj(stage, "normalizationFrequency", Frequency) normalization_factor = _attr2obj(stage, "normalizationFactor", float) # Parse the type of the transfer function # A: Laplace (rad) # B: Laplace (Hz) # D: digital (z-transform) pz_transfer_function_type = _attr2obj(stage, "type", str) if pz_transfer_function_type == 'A': pz_transfer_function_type = 'LAPLACE (RADIANS/SECOND)' elif pz_transfer_function_type == 'B': pz_transfer_function_type = 'LAPLACE (HERTZ)' elif pz_transfer_function_type == 'D': pz_transfer_function_type = 'DIGITAL (Z-TRANSFORM)' else: msg = ("Unknown transfer function code %s. Defaulting to Laplace" "(rad)") % pz_transfer_function_type warnings.warn(msg) pz_transfer_function_type = 'LAPLACE (RADIANS/SECOND)' # Parse string of poles and zeros # paz are stored as a string in arclinkXML # e.g. (-0.01234,0.01234) (-0.01234,-0.01234) zeros_array = stage.find(_ns("zeros")).text poles_array = stage.find(_ns("poles")).text if zeros_array is not None: zeros_array = zeros_array.split(" ") else: zeros_array = [] if poles_array is not None: poles_array = poles_array.split(" ") else: poles_array = [] # Keep counter for pole/zero number cnt = 0 poles = [] zeros = [] for el in poles_array: poles.append(_tag2pole_or_zero(el, cnt)) cnt += 1 for el in zeros_array: zeros.append(_tag2pole_or_zero(el, cnt)) cnt += 1 # Return the paz response return PolesZerosResponseStage( pz_transfer_function_type=pz_transfer_function_type, normalization_frequency=normalization_freq, normalization_factor=normalization_factor, zeros=zeros, poles=poles, **kwargs) elif elem_type == 'datalogger': cf_transfer_function_type = "DIGITAL" numerator = [] denominator = [] return CoefficientsTypeResponseStage( cf_transfer_function_type=cf_transfer_function_type, numerator=numerator, denominator=denominator, **kwargs) elif elem_type == 'responsePolynomial': raise NotImplementedError("responsePolynomial not" "implemented. Contact the ObsPy developers") # Polynomial response (UNTESTED) # Currently not implemented in ObsPy (20-11-2015) f_low = None f_high = None max_err = None appr_type = _attr2obj(stage, "approximationType", str) appr_low = _attr2obj(stage, "approximationLowerBound", float) appr_high = _attr2obj(stage, "approximationUpperBound", float) coeffs_str = _tag2obj(stage, _ns("coefficients"), str) if coeffs_str is not None: coeffs = coeffs_str.split(" ") coeffs_float = [] i = 0 # pass additional mapping of coefficient counter # so that a proper stationXML can be formatted for c in coeffs: temp = _read_float_var(c, FilterCoefficient, additional_mapping={str("number"): i}) coeffs_float.append(temp) i += 1 return PolynomialResponseStage( approximation_type=appr_type, frequency_lower_bound=f_low, frequency_upper_bound=f_high, approximation_lower_bound=appr_low, approximation_upper_bound=appr_high, maximum_error=max_err, coefficients=coeffs, **kwargs) elif elem_type == 'responseFIR': # For the responseFIR obtain the symmetry and # list of coefficients coeffs_str = _tag2obj(stage, _ns("coefficients"), str) coeffs_float = [] if coeffs_str is not None and coeffs_str != 'None': coeffs = coeffs_str.split(" ") i = 0 # pass additional mapping of coefficient counter # so that a proper stationXML can be formatted for c in coeffs: temp = _read_float_var(c, FilterCoefficient, additional_mapping={str("number"): i}) coeffs_float.append(temp) i += 1 # Write the FIR symmetry to what ObsPy expects # A = NONE, B = ODD, C = EVEN symmetry = _attr2obj(stage, "symmetry", str) if symmetry == 'A': symmetry = 'NONE' elif symmetry == 'B': symmetry = 'ODD' elif symmetry == 'C': symmetry = 'EVEN' else: raise ValueError('Unknown symmetry metric; expected A, B, or C') return FIRResponseStage( coefficients=coeffs_float, symmetry=symmetry, **kwargs) else: raise NotImplementedError
[docs]def _tag2pole_or_zero(paz_element, count): """ Parses arclinkXML paz format Uncertainties on poles removed, not present in fo Always put to None so no internal conflict The sanitization removes the first/last parenthesis and split by comma, real part is 1st, imaginary 2nd :param paz_element: string of poles or zeros e.g. (12320, 23020) :param count: sequential numbering of poles/zeros """ paz_element = paz_element[1:-1] paz_element = paz_element.split(",") real = float(paz_element[0]) imag = float(paz_element[1]) if real is not None or imag is not None: real = real or 0 imag = imag or 0 x = ComplexWithUncertainties(real, imag) x.upper_uncertainty = None x.upper_uncertainty = None x.number = count return x
[docs]def _read_float_var(elem, cls, unit=False, datum=False, additional_mapping={}): """ function to read floattype to cls object (based on _read_floattype) normally ObsPy would read this directly from a tag, but with different tag names this is no longer possible; instead we just pass the value and not the tag name. We always set the unit/datum/uncertainties to None because they are not provided. :param elem: float value to be converted :param cls: obspy.core.inventory class """ try: convert = float(elem) except (ValueError, TypeError): warnings.warn( "Encountered a value '%s' which could not be converted to a " "float. Will be skipped. Please contact to report this " "issue." % elem, UserWarning) return None if math.isnan(convert): warnings.warn("'%s' has a value of NaN. It will be skipped." % elem, UserWarning) return None obj = cls(convert) if unit: obj.unit = None if datum: obj.datum = None obj.lower_uncertainty = None obj.upper_uncertainty = None for key1, key2 in additional_mapping.items(): setattr(obj, key1, key2) return obj