# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
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)
