Brown’s Double Exponential Smoothing¶
Local Algorithm - One-Dimensional Algorithm
The basic formulas of the Brown’s Double Exponential Smoothing algorithm are stated as follows:
(1)s′0=Y0,
(2)s0″
(3) \quad s^{'}_t = \alpha Y_t + (1-\alpha) s^{'}_{t-1} \, \text{,}
(4) \quad s^{''}_t = \alpha s^{'}_t + (1-\alpha) s^{''}_{t-1} \, \text{,}
(5) \quad a_t = 2 s^{'}_t - s^{''}_t \, \text{,}
(6) \quad b_t = \frac{\alpha}{1-\alpha} (s^{'}_t - s^{''}_t) \, \text{,}
(7) \quad \hat{Y}_{t+m} = a_t + m b_t \, \text{,}
where Y is the data sequence beginning at time t = 0 and \hat{Y}_{t+m} is the smoothed forecast for time t + m.
Input Parameters
Parameter | Type | Constraint | Description | Remarks |
---|---|---|---|---|
Y | Y \in \mathbb R^N | N \in \mathbb{N} | Input data sequence of length N | |
\alpha | \alpha \in \mathbb R | 0 \leq \alpha \leq 1 |
Output Parameters
Parameter | Type | Constraint | Description | Remarks |
---|---|---|---|---|
\hat{Y} | \hat{Y} \in \mathbb R^N |
Tool Support
Single Steps using the Algorithm
References
NIST/SEMATECH e-Handbook of Statistical Methods