Bias correction in exponentially weighted averages

Biased correction can make the computation of these averages more accurately.

When , the purple line starts at low value. How can we fix that?

Example:

and

so and are not good estimate and there is a method to compute more better estimate.

when then

This bias correction works better at the intial stage, because when is large, , so bias correction factor has no effect when is sufficiently large.