    def get_decay(self, optimization_step: int) -> float:
        """
        Compute the decay factor for the exponential moving average.
        """
        step = max(0, optimization_step - self.update_after_step - 1)

        if step <= 0:
            return 0.0

        if self.use_ema_warmup:
            cur_decay_value = 1 - (1 + step / self.inv_gamma) ** -self.power
        else:
            cur_decay_value = (1 + step) / (10 + step)

        cur_decay_value = min(cur_decay_value, self.decay)
        # make sure decay is not smaller than min_decay
        cur_decay_value = max(cur_decay_value, self.min_decay)
        return cur_decay_value
Compute the decay factor for the exponential moving average.
opensora/utils/ema.py