torch.signal.windows.blackman

torch.signal.windows.blackman(M, *, sym=True, dtype=None, layout=torch.strided, device=None, requires_grad=False)

Computes the Blackman window.

The Blackman window is defined as follows:

$$w_n = 0.42 - 0.5 \cos \left( \frac{2 \pi n}{M - 1} \right) + 0.08 \cos \left( \frac{4 \pi n}{M - 1} \right)$$

The window is normalized to 1 (maximum value is 1). However, the 1 doesn’t appear if M is even and sym is True.

Parameters:

M (int) – the length of the window. In other words, the number of points of the returned window.

Keyword Arguments:

• sym (bool, optional) – If False, returns a periodic window suitable for use in spectral analysis. If True, returns a symmetric window suitable for use in filter design. Default: True.

• dtype (torch.dtype, optional) – the desired data type of returned tensor. Default: if None, uses a global default (see torch.set_default_tensor_type()).

• layout (torch.layout, optional) – the desired layout of returned Tensor. Default: torch.strided.

• device (torch.device, optional) – the desired device of returned tensor. Default: if None, uses the current device for the default tensor type (see torch.set_default_tensor_type()). device will be the CPU for CPU tensor types and the current CUDA device for CUDA tensor types.

• requires_grad (bool, optional) – If autograd should record operations on the returned tensor. Default: False.

Return type:

Tensor

Examples:

>>> # Generates a symmetric Blackman window.
>>> torch.signal.windows.blackman(5)
tensor([-1.4901e-08,  3.4000e-01,  1.0000e+00,  3.4000e-01, -1.4901e-08])

>>> # Generates a periodic Blackman window.
>>> torch.signal.windows.blackman(5, sym=False)
tensor([-1.4901e-08,  2.0077e-01,  8.4923e-01,  8.4923e-01,  2.0077e-01])