def lsf_to_lpc(all_lsf):
if len(all_lsf.shape) < 2:
all_lsf = all_lsf[None]
order = all_lsf.shape[1]
all_lpc = np.zeros((len(all_lsf), order + 1))
for i in range(len(all_lsf)):
lsf = all_lsf[i]
zeros = np.exp(1j * lsf)
sum_zeros = zeros[::2]
diff_zeros = zeros[1::2]
sum_zeros = np.hstack((sum_zeros, np.conj(sum_zeros)))
diff_zeros = np.hstack((diff_zeros, np.conj(diff_zeros)))
sum_filt = np.poly(sum_zeros)
diff_filt = np.poly(diff_zeros)
if order % 2 != 0:
deconv_diff = sg.convolve(diff_filt, [1, 0, -1])
deconv_sum = sum_filt
else:
deconv_diff = sg.convolve(diff_filt, [1, -1])
deconv_sum = sg.convolve(sum_filt, [1, 1])
lpc = .5 * (deconv_sum + deconv_diff)
# Last coefficient is 0 and not returned
all_lpc[i] = lpc[:-1]
return np.squeeze(all_lpc)
python类poly()的实例源码
def lsf_to_lpc(all_lsf):
if len(all_lsf.shape) < 2:
all_lsf = all_lsf[None]
order = all_lsf.shape[1]
all_lpc = np.zeros((len(all_lsf), order + 1))
for i in range(len(all_lsf)):
lsf = all_lsf[i]
zeros = np.exp(1j * lsf)
sum_zeros = zeros[::2]
diff_zeros = zeros[1::2]
sum_zeros = np.hstack((sum_zeros, np.conj(sum_zeros)))
diff_zeros = np.hstack((diff_zeros, np.conj(diff_zeros)))
sum_filt = np.poly(sum_zeros)
diff_filt = np.poly(diff_zeros)
if order % 2 != 0:
deconv_diff = sg.convolve(diff_filt, [1, 0, -1])
deconv_sum = sum_filt
else:
deconv_diff = sg.convolve(diff_filt, [1, -1])
deconv_sum = sg.convolve(sum_filt, [1, 1])
lpc = .5 * (deconv_sum + deconv_diff)
# Last coefficient is 0 and not returned
all_lpc[i] = lpc[:-1]
return np.squeeze(all_lpc)
def test_objects(self):
from decimal import Decimal
p = np.poly1d([Decimal('4.0'), Decimal('3.0'), Decimal('2.0')])
p2 = p * Decimal('1.333333333333333')
assert_(p2[1] == Decimal("3.9999999999999990"))
p2 = p.deriv()
assert_(p2[1] == Decimal('8.0'))
p2 = p.integ()
assert_(p2[3] == Decimal("1.333333333333333333333333333"))
assert_(p2[2] == Decimal('1.5'))
assert_(np.issubdtype(p2.coeffs.dtype, np.object_))
p = np.poly([Decimal(1), Decimal(2)])
assert_equal(np.poly([Decimal(1), Decimal(2)]),
[1, Decimal(-3), Decimal(2)])
def test_zero_dims(self):
try:
np.poly(np.zeros((0, 0)))
except ValueError:
pass
def test_poly_int_overflow(self):
"""
Regression test for gh-5096.
"""
v = np.arange(1, 21)
assert_almost_equal(np.poly(v), np.poly(np.diag(v)))
