This it the legacy apply when count was a Long
Create a Moments object given a single value.
Create a Moments object given a single value. This is useful for initializing moment calculations at the start of a stream.
Given two streams of doubles (weightN, an) and (weightK, ak) of form (weighted count, mean), calculates the mean of the combined stream.
Given two streams of doubles (weightN, an) and (weightK, ak) of form (weighted count, mean), calculates the mean of the combined stream.
Uses a more stable online algorithm which should be suitable for large numbers of records similar to: http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm
This differs from the implementation in MomentsGroup.scala only in that here, the counts are weighted, and are thus doubles instead of longs
This it the legacy unapply when count was a Long