def test_get_filter_retrograde(synthetic_data):
TOL = 0.05
POLARIZATION = 'retrograde'
az_retro, n, e, v, fs = synthetic_data
Sn = stransform(n, Fs=fs, return_time_freq=False)
Se = stransform(e, Fs=fs)
Sv = stransform(v, Fs=fs)
xpr = filt.xpr(az_retro)
with np.errstate(divide='ignore', invalid='ignore'):
theta = filt.instantaneous_azimuth(Sv, Sn, Se, POLARIZATION, xpr)
Sr, St = filt.rotate_NE_RT(Sn, Se, theta)
NIP = filt.NIP(Sr, Sv, polarization=POLARIZATION, eps=0.04)
f = filt.get_filter(NIP, POLARIZATION, threshold=0.8, width=0.1)
Srf = Sr * f
Svf = Sv * f
assert abs(Srf[idx_5hz, idx_10sec]) == pytest.approx(0.0, abs=TOL)
assert abs(Srf[idx_2hz, idx_10sec]) == pytest.approx(0.5, abs=TOL)
assert abs(Srf[idx_1hz, idx_10sec]) == pytest.approx(0.0, abs=TOL)
rf = istransform(Sr * f, Fs=fs)
tf = istransform(St * f, Fs=fs)
vf = istransform(Sv * f, Fs=fs)
assert tf.max() == pytest.approx(0.0, abs=TOL)
assert rf.max() == pytest.approx(0.5, abs=TOL)
assert vf.max() == pytest.approx(1.0, abs=TOL)
def test_stransform(synthetic_data):
"""
The forward/inverse S transform roundtrip gives me back what I started with.
"""
az_retro, n, e, v, fs = synthetic_data
Sn = stransform(n, Fs=fs)
n_roundtrip = istransform(Sn, Fs=fs)
assert np.allclose(n_roundtrip, n)
def test_scalar_azimuth_prograde(synthetic_data):
TOL = 1.0 # [degrees]
POLARIZATION = 'prograde'
az_retro, n, e, v, fs = synthetic_data
Sn = stransform(n, Fs=fs, return_time_freq=False)
Se = stransform(e, Fs=fs)
Sv = stransform(v, Fs=fs)
xpr = filt.xpr(az_retro)
with np.errstate(divide='ignore', invalid='ignore'):
theta = filt.instantaneous_azimuth(Sv, Sn, Se, POLARIZATION, xpr)
Sr, St = filt.rotate_NE_RT(Sn, Se, theta)
NIP = filt.NIP(Sr, Sv, polarization=POLARIZATION, eps=0.04)
f = filt.get_filter(NIP, POLARIZATION, threshold=0.8, width=0.1)
Svhat = filt.shift_phase(Sv, POLARIZATION)
ef = istransform(Se * f, Fs=fs)
nf = istransform(Sn * f, Fs=fs)
vfhat = istransform(Svhat * f, Fs=fs)
az = filt.scalar_azimuth(ef, nf, vfhat)
assert az == pytest.approx(az_retro + 90, abs=TOL)