Source code for pyrocko.io.gse1

# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
from __future__ import absolute_import, division

import sys
import numpy as num

from .io_common import FileLoadError
from pyrocko import util, trace


[docs]class GSE1LoadError(FileLoadError): pass
[docs]class EOF(Exception): pass
def read_xw01(f): line = f.readline() if not line[:4] == 'XW01': raise GSE1LoadError( '"XW01" marker not found, maybe this is not a GSE1 file') f.readline() def read_wid1(f): line = f.readline() if not line.strip(): raise EOF() (wid1, stmin, imilli, nsamples, sta, channel_id, channel_name, sample_rate, system_type, data_format, diff_flag) = util.unpack_fixed( 'a4,x1,a17,x1,i3,x1,i8,x1,a6,x1,a8,x1,a2,x1,f11,x1,a6,x1,a4,x1,i1', line[:80]) if wid1 != 'WID1': raise GSE1LoadError('"WID1" marker expected but not found.') tmin = util.str_to_time(stmin, format='%Y%j %H %M %S') + 0.001*imilli line = f.readline() (gain, units, calib_period, lat, lon, elevation, depth, beam_azimuth, beam_slowness, horizontal_orientation) = util.unpack_fixed( 'f9,i1,f7,x1,f9,x1,f9,x1,f9,x1,f9,x1,f7,x1,f7,x1,f6', line[:80]) return (tmin, nsamples, sta, channel_id, channel_name, sample_rate, system_type, data_format, diff_flag, gain, units, calib_period, lat, lon, elevation, depth, beam_azimuth, beam_slowness, horizontal_orientation) def read_dat1_chk1(f, data_format, diff_flag, nsamples): dat1 = f.readline()[:4] if dat1 != 'DAT1': raise GSE1LoadError('"DAT1" marker expected but not found.') if data_format == 'INTV' and diff_flag == 0: samples = [] while len(samples) < nsamples: samples.extend(map(float, f.readline().split())) data = num.array(samples[:nsamples], dtype=int) else: raise GSE1LoadError( 'GSE1 data format %s with differencing=%i not supported.' % (data_format, diff_flag)) line = f.readline() if not line.startswith('CHK1'): raise GSE1LoadError('"CHK1" marker expected but not found.') t = line.split() try: checksum = int(t[1]) except Exception: raise GSE1LoadError('could not parse CHK1 section') f.readline() return data, checksum def skip_dat1_chk1(f, data_format, diff_flag, nsamples): dat1 = f.readline()[:4] if dat1 != 'DAT1': raise GSE1LoadError('"DAT1" marker expected but not found.') while True: if f.readline().startswith('CHK1'): break f.readline() def iload(filename, load_data=True): with open(filename, 'r') as f: read_xw01(f) try: while True: h = read_wid1(f) (tmin, nsamples, sta, chid, cha, sample_rate, _, data_format, diff_flag, gain) = h[:10] deltat = 1.0/sample_rate if load_data: ydata, checksum = read_dat1_chk1( f, data_format, diff_flag, nsamples) tmax = None else: skip_dat1_chk1(f, data_format, diff_flag, nsamples) ydata = None tmax = tmin + (nsamples-1)*deltat yield trace.Trace( '', sta, '', cha, tmin=tmin, tmax=tmax, deltat=deltat, ydata=ydata) except EOF: pass def detect(first512): lines = first512.splitlines() if len(lines) >= 5 and \ lines[0].startswith(b'XW01') and lines[2].startswith(b'WID1') and \ lines[4].startswith(b'DAT1'): return True return False if __name__ == '__main__': all_traces = [] for fn in sys.argv[1:]: all_traces.extend(iload(fn)) trace.snuffle(all_traces)