Coverage for /usr/local/lib/python3.7/dist-packages/pyrocko/pz.py : 58%

# http://pyrocko.org - GPLv3 

# 

# The Pyrocko Developers, 21st Century 

# ---|P------/S----------~Lg---------- 

from __future__ import absolute_import 

import math 

import numpy as num 

try: 

from StringIO import StringIO as BytesIO 

except ImportError: 

from io import BytesIO 

from pyrocko import trace 

d2r = math.pi/180. 

class SacPoleZeroError(Exception): 

pass 

def read_sac_zpk(filename=None, file=None, string=None, get_comments=False): 

''' 

Read SAC Pole-Zero file. 

Returns (zeros, poles, constant). 

''' 

if filename is not None: 

f = open(filename, 'rb') 

elif file is not None: 

f = file 

elif string is not None: 

f = BytesIO(string) 

sects = ('ZEROS', 'POLES', 'CONSTANT') 

sectdata = {'ZEROS': [], 'POLES': []} 

npoles = 0 

nzeros = 0 

constant = 1.0 

atsect = None 

comments = [] 

for iline, line in enumerate(f): 

line = str(line.decode('ascii')) 

toks = line.split() 

if len(toks) == 0: 

continue 

if toks[0][0] in '*#': 

comments.append(line) 

continue 

if len(toks) != 2: 

f.close() 

raise SacPoleZeroError( 

'Expected 2 tokens in line %i of file %s' 

% (iline+1, filename)) 

if toks[0].startswith('*'): 

continue 

lsect = toks[0].upper() 

if lsect in sects: 

atsect = lsect 

sectdata[atsect] = [] 

if lsect.upper() == 'ZEROS': 

nzeros = int(toks[1]) 

elif toks[0].upper() == 'POLES': 

npoles = int(toks[1]) 

elif toks[0].upper() == 'CONSTANT': 

constant = float(toks[1]) 

else: 

if atsect: 

sectdata[atsect].append( 

complex(float(toks[0]), float(toks[1]))) 

if f != file: 

f.close() 

poles = sectdata['POLES'] 

zeros = sectdata['ZEROS'] 

npoles_ = len(poles) 

nzeros_ = len(zeros) 

if npoles_ > npoles: 

raise SacPoleZeroError( 

'Expected %i poles but found %i in pole-zero file "%s"' 

% (npoles, npoles_, filename)) 

if nzeros_ > nzeros: 

raise SacPoleZeroError( 

'Expected %i zeros but found %i in pole-zero file "%s"' 

% (nzeros, nzeros_, filename)) 

if npoles_ < npoles: 

poles.extend([complex(0.)]*(npoles-npoles_)) 

if nzeros_ < npoles: 

zeros.extend([complex(0.)]*(nzeros-nzeros_)) 

if len(poles) == 0 and len(zeros) == 0: 

raise SacPoleZeroError( 

'No poles and zeros found in file "%s"' % (filename)) 

if not num.all(num.isfinite(poles)): 

raise SacPoleZeroError( 

'Not finite pole(s) found in pole-zero file "%s"' 

% (constant, filename)) 

if not num.all(num.isfinite(zeros)): 

raise SacPoleZeroError( 

'Not finite zero(s) found in pole-zero file "%s"' 

% (constant, filename)) 

if not num.isfinite(constant): 

raise SacPoleZeroError( 

'Ivalid constant (%g) found in pole-zero file "%s"' 

% (constant, filename)) 

if get_comments: 

return zeros, poles, constant, comments 

else: 

return zeros, poles, constant 

def write_sac_zpk(zeros, poles, constant, filename): 

if hasattr(filename, 'write'): 

f = filename 

else: 

f = open('w', filename) 

def write_complex(x): 

f.write('%12.8g %12.8g\n' % (complex(x).real, complex(x).imag)) 

f.write('POLES %i\n' % len(poles)) 

for p in poles: 

if p != 0.0: 

write_complex(p) 

f.write('ZEROS %i\n' % len(zeros)) 

for z in zeros: 

if z != 0.0: 

write_complex(z) 

f.write('CONSTANT %12.8g\n' % constant) 

if not hasattr(filename, 'write'): 

f.close() 

def evaluate(zeros, poles, constant, fmin=0.001, fmax=100., nf=100): 

logfmin = math.log(fmin) 

logfmax = math.log(fmax) 

logf = num.linspace(logfmin, logfmax, nf) 

f = num.exp(logf) 

trans = trace.PoleZeroResponse(zeros, poles, constant) 

return f, trans.evaluate(f) 

def evaluate_at(zeros, poles, constant, f): 

jomeg = 1.0j * 2. * math.pi * f 

a = constant 

for z in zeros: 

a *= jomeg-z 

for p in poles: 

a /= jomeg-p 

return a 

def plot_amplitudes_zpk( 

zpks, filename_pdf, 

fmin=0.001, 

fmax=100., 

nf=100, 

fnorm=None): 

from pyrocko.plot import gmtpy 

p = gmtpy.LogLogPlot(width=30*gmtpy.cm, yexp=0) 

for i, (zeros, poles, constant) in enumerate(zpks): 

f, h = evaluate(zeros, poles, constant, fmin, fmax, nf) 

if fnorm is not None: 

h /= evaluate_at(zeros, poles, constant, fnorm) 

amp = num.abs(h) 

p.plot((f, amp), '-W2p,%s' % gmtpy.color(i)) 

p.save(filename_pdf) 

def plot_phases_zpk(zpks, filename_pdf, fmin=0.001, fmax=100., nf=100): 

from pyrocko.plot import gmtpy 

p = gmtpy.LogLinPlot(width=30*gmtpy.cm) 

for i, (zeros, poles, constant) in enumerate(zpks): 

f, h = evaluate(zeros, poles, constant, fmin, fmax, nf) 

phase = num.unwrap(num.angle(h)) / d2r 

p.plot((f, phase), '-W1p,%s' % gmtpy.color(i)) 

p.save(filename_pdf)