Negative weighted sum divided by the ordinary sum over a full period,
assigning weight one to the newest value and period to the oldest. Equal
values remain separate observations. A zero compensated ordinary sum and
warmup are NaN; a nonzero sum is never discarded using an epsilon cutoff.
Ratios beyond the finite number range yield signed Infinity.
Missing values propagate by default; skip weights the last period finite
observations and holds across gaps. Invalid periods throw RangeError;
unknown missing policies throw TypeError.
Negative weighted sum divided by the ordinary sum over a full period, assigning weight one to the newest value and period to the oldest. Equal values remain separate observations. A zero compensated ordinary sum and warmup are NaN; a nonzero sum is never discarded using an epsilon cutoff. Ratios beyond the finite number range yield signed Infinity. Missing values propagate by default;
skipweights the last period finite observations and holds across gaps. Invalid periods throw RangeError; unknown missing policies throw TypeError.