The iteration threshold γi is defined as the empirical (1−p)-quantile of the current batch of samples drawn from the proposal distribution. The loop stops when this threshold γi is greater than or equal to the target rare-event threshold γ.
Conditions: Samples are drawn from the current proposal distribution.; The elite fraction parameter p is set to 0.05.; The target threshold is γ=5.
The iteration threshold γi is defined as the empirical (1−p)-quantile of the current batch of samples drawn from the proposal distribution. The loop stops when this threshold γi is greater than or equal to the target rare-event threshold γ.
Conditions: Samples are drawn from the current proposal distribution.; The elite fraction parameter p is set to 0.05.; The target threshold is γ=5.
The video states that the earlier example 'cheated' because the rare event was not very rare, making direct rejection sampling from g∗ computationally feasible. In general, for truly rare events, direct rejection sampling would take too long, which motivates the use of the adaptive cross-entropy method.
Conditions: The context is comparing the improved cross-entropy method to the original cross-entropy method.; The rare event in the earlier example had a relatively high probability.
The video states that the earlier example 'cheated' because the rare event was not very rare, making direct rejection sampling from g∗ computationally feasible. In general, for truly rare events, direct rejection sampling would take too long, which motivates the use of the adaptive cross-entropy method.
Conditions: The context is comparing the improved cross-entropy method to the original cross-entropy method.; The rare event in the earlier example had a relatively high probability.