def test_coherency_multi_taper():
"""Tests that the coherency algorithm runs smoothly, using the multi_taper
csd routine and that the resulting matrix is symmetric"""
t = np.linspace(0,16*np.pi,1024)
x = np.sin(t) + np.sin(2*t) + np.sin(3*t) + np.random.rand(t.shape[-1])
y = x + np.random.rand(t.shape[-1])
method = {"this_method":'multi_taper_csd',
"Fs":2*np.pi}
f,c = tsa.coherency(np.vstack([x,y]),csd_method=method)
np.testing.assert_array_almost_equal(c[0,1],c[1,0].conjugate())
np.testing.assert_array_almost_equal(c[0,0],np.ones(f.shape))
def test_coherency_cached():
"""Tests that the cached coherency gives the same result as the standard
coherency"""
t = np.linspace(0,16*np.pi,1024)
x = np.sin(t) + np.sin(2*t) + np.sin(3*t) + np.random.rand(t.shape[-1])
y = x + np.random.rand(t.shape[-1])
f1,c1 = tsa.coherency(np.vstack([x,y]))
ij = [(0,1),(1,0)]
f2,cache = tsa.cache_fft(np.vstack([x,y]),ij)
c2 = tsa.cache_to_coherency(cache,ij)
np.testing.assert_array_almost_equal(c1[1,0],c2[1,0])
np.testing.assert_array_almost_equal(c1[0,1],c2[0,1])
def test_coherency_mlab():
"""Tests that the coherency algorithm runs smoothly, using the mlab csd
routine, that the resulting matrix is symmetric and that the frequency bands
in the output make sense"""
t = np.linspace(0,16*np.pi,1024)
x = np.sin(t) + np.sin(2*t) + np.sin(3*t) + np.random.rand(t.shape[-1])
y = x + np.random.rand(t.shape[-1])
method = {"this_method":'mlab',
"NFFT":256,
"Fs":2*np.pi}
f,c = tsa.coherency(np.vstack([x,y]),csd_method=method)
np.testing.assert_array_almost_equal(c[0,1],c[1,0].conjugate())
np.testing.assert_array_almost_equal(c[0,0],np.ones(f.shape))
f_theoretical = ut.get_freqs(method['Fs'],method['NFFT'])
np.testing.assert_array_almost_equal(f,f_theoretical)
