A numeric vector of equal length as x
with damped variation.
The dampening is calculated as:
$$
S(t+1) - S(t) = (X(t+1) - S(t)) / \tau
$$
Where \(X\) is the daily varying time series given by argument x
,
\(S\) is the dampened time returned by this function, and \(\tau\) is
the decay time scale of a perturbation, given by argument tau
.