class beta_wavelet(discrete_wavelet):
def __init__(self, alpha: float = 1.0, beta: float = 1.0, name: str = 'beta_wavelet', *args, **kwargs):
super().__init__(name=name, *args, **kwargs)
self.alpha = alpha
self.beta = beta
if self.alpha < 1.0 or self.beta < 1.0:
raise ValueError('alpha and beta must be >= 1.')
def psi(self, tau: torch.Tensor):
if not torch.all((tau >= 0) & (tau <= 1)):
tau = torch.sigmoid(tau)
assert torch.all((tau >= 0) & (tau <= 1))
beta_coeff = 1.0/beta(self.alpha, self.beta)
return beta_coeff * tau**(self.alpha - 1) * (1.0 - tau)**(self.beta - 1.0)