pub fn exponential_smoothing_into(
values: &[f64],
alpha: f64,
out: &mut [f64],
) -> Option<usize>Expand description
Single (Brown’s) exponential smoothing with factor alpha ∈ (0, 1],
written into out (same length as values).
s_0 = x_0; s_t = alpha·x_t + (1 − alpha)·s_{t−1}. Returns the number of
values written, or None if the series is empty, out is too small, or
alpha is not in (0, 1].