Source code for diffsptk.modules.lar2par
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import torch
from torch import nn
from ..misc.utils import check_size
[docs]
class LogAreaRatioToParcorCoefficients(nn.Module):
"""See `this page <https://sp-nitech.github.io/sptk/latest/main/lar2par.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, g):
"""Convert LAR to PARCOR.
Parameters
----------
g : Tensor [shape=(..., M+1)]
Log area ratio.
Returns
-------
out : Tensor [shape=(..., M+1)]
PARCOR coefficients.
Examples
--------
>>> g = diffsptk.ramp(1, 4) * 0.1
>>> lar2par = diffsptk.LogAreaRatioToParcorCoefficients(3)
>>> k = lar2par(g)
>>> k
tensor([0.1000, 0.0997, 0.1489, 0.1974])
"""
check_size(g.size(-1), self.par_order + 1, "dimension of parcor")
return self._forward(g)
@staticmethod
def _forward(g):
K, g = torch.split(g, [1, g.size(-1) - 1], dim=-1)
k = torch.cat((K, torch.tanh(0.5 * g)), dim=-1)
return k
_func = _forward