MomentsGroup
Related Doc:
package algebird
These are from algebra.Monoid
Returns an instance of
T calculated by summing all instances in iter in one pass.
Returns an instance of
T calculated by summing all instances in iter in one pass. Returns None if
iter is empty, else Some[
T].
None if iter is empty, else an option value containing the summed
T
Override if there is a faster way to compute this sum than iter.reduceLeftOption using plus.
Given two streams of doubles (n, an) and (k, ak) of form (count, mean), calculates the mean of the combined stream.
Given two streams of doubles (n, an) and (k, ak) of form (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
we no longer use this, but we can't remove it due to binary compatibility
(Since version 0.13.8) Use Moments.getCombinedMeanDouble instead
This should not be used as a group (avoid negate and minus). It was wrongly believed that this was a group for several years in this code, however it was only being tested with positive counts (which is to say the generators were too weak). It isn't the case that minus and negate are totally wrong but (a - a) + b in general isn't associative: it won't equal a - (a - b) which it should.
(Since version 0.13.8) use Moments.momentsMonoid, this isn't lawful for negative counts