Source code for diffsptk.modules.par2lar
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import torch
from torch import nn
from ..misc.utils import check_size
[docs]
class ParcorCoefficientsToLogAreaRatio(nn.Module):
"""See `this page <https://sp-nitech.github.io/sptk/latest/main/par2lar.html>`_
for details.
Parameters
----------
par_order : int >= 0
Order of PARCOR, :math:`M`.
"""
def __init__(self, par_order):
super().__init__()
assert 0 <= par_order
self.par_order = par_order
[docs]
def forward(self, k):
"""Convert PARCOR to LAR.
Parameters
----------
k : Tensor [shape=(..., M+1)]
PARCOR coefficients.
Returns
-------
out : Tensor [shape=(..., M+1)]
Log area ratio.
Examples
--------
>>> k = diffsptk.ramp(1, 4) * 0.1
>>> par2lar = diffsptk.ParcorCoefficientsToLogAreaRatio(3)
>>> lar2par = diffsptk.LogAreaRatioToParcorCoefficients(3)
>>> k2 = lar2par(par2lar(k))
>>> k2
tensor([0.1000, 0.2000, 0.3000, 0.4000])
"""
check_size(k.size(-1), self.par_order + 1, "dimension of parcor")
return self._forward(k)
@staticmethod
def _forward(k):
K, k = torch.split(k, [1, k.size(-1) - 1], dim=-1)
g = torch.cat((K, 2 * torch.atanh(k)), dim=-1)
return g
_func = _forward