Exponential moving average — a period-span EMA (α = 2/(period+1), the
financial convention), appended as a new column. Length-preserving warm-up
(undefined for the first period - 1 bars) via the ema minSamples gate,
so it lines up on the source's time axis. Composes on core's smooth('ema').
Exponential moving average — a
period-span EMA (α = 2/(period+1), the financial convention), appended as a new column. Length-preserving warm-up (undefinedfor the firstperiod - 1bars) via the emaminSamplesgate, so it lines up on the source's time axis. Composes on core'ssmooth('ema').