Like calling andThen on the present function
Like calling andThen on the present function
This may error if inputs are empty (for Monoid Aggregators it never will, instead you see present(Monoid.
This may error if inputs are empty (for Monoid Aggregators it never will, instead you see present(Monoid.zero[B])
This returns the cumulative sum of its inputs, in the same order.
This returns the cumulative sum of its inputs, in the same order. If the inputs are empty, the result will be empty too.
This returns None if the inputs are empty
This returns None if the inputs are empty
Like calling compose on the prepare function
Like calling compose on the prepare function
This returns the cumulative sum of its inputs, in the same order.
This returns the cumulative sum of its inputs, in the same order. If the inputs are empty, the result will be empty too.
This allows you to run two aggregators on the same data with a single pass
This allows you to run two aggregators on the same data with a single pass
This is the depth parameter for the QTreeSemigroup
This is the depth parameter for the QTreeSemigroup
We convert T to a Double, then the Double is converted to a Long by using a 2^level bucket size.
We convert T to a Double, then the Double is converted to a Long by using a 2^level bucket size.
This may error if items is empty.
This may error if items is empty. To be safe you might use reduceOption if you don't know that items is non-empty
combine two inner values
combine two inner values
This is the safe version of the above.
This is the safe version of the above. If the input in empty, return None, else reduce the items
An Aggregator can be converted to a Fold, but not vice-versa Note, a Fold is more constrained so only do this if you require joining a Fold with an Aggregator to produce a Fold
An Aggregator can be converted to a Fold, but not vice-versa Note, a Fold is more constrained so only do this if you require joining a Fold with an Aggregator to produce a Fold
This allows you to join two aggregators into one that takes a tuple input, which in turn allows you to chain .
This allows you to join two aggregators into one that takes a tuple input, which in turn allows you to chain .composePrepare onto the result if you have an initial input that has to be prepared differently for each of the joined aggregators.
The law here is: ag1.zip(ag2).apply(as.zip(bs)) == (ag1(as), ag2(bs))
QTreeAggregatorLowerBound is an aggregator that is used to find an appoximate percentile. This is similar to a QTreeAggregator, but is a convenience because instead of returning an Intersection, it instead returns the lower bound of the percentile. Like a QTreeAggregator, the items that are iterated over to produce this approximation cannot be negative.