# Codeblock 16a
class NoiseScheduler:
    def __init__(self):
        self.betas = torch.linspace(BETA_START, BETA_END, NUM_TIMESTEPS)  #(1)
        self.alphas = 1. - self.betas
        self.alphas_cum_prod = torch.cumprod(self.alphas, dim=0)
        self.sqrt_alphas_cum_prod = torch.sqrt(self.alphas_cum_prod)
        self.sqrt_one_minus_alphas_cum_prod = torch.sqrt(1. - self.alphas_cum_prod)