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# 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 

 

 

class GSE1LoadError(FileLoadError): 

pass 

 

 

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=num.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)