Flags a reading that stands out from the ones before it.
Creates a detector that flags a reading sigmas deviations from the mean of up to capacity readings before it, 32 unless told fewer.
sigmas
capacity
A spread needs two readings, so capacity is at least 2.
Optional
How many readings the baseline keeps.
Folds a reading in and reports whether it stands out.
Nothing is flagged before two readings are held; from the third on, a reading can be, and one that is not a finite number always is.
Flags a reading that stands out from the ones before it.