Portability | non-portable |
---|---|
Stability | experimental |
Maintainer | Edward Kmett <ekmett@gmail.com> |
Safe Haskell | None |
This package provides an approximate streaming (constant space) unique object counter.
See the original paper for details: http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf
- newtype HyperLogLog p = HyperLogLog {}
- class HasHyperLogLog t p | t -> p where
- hyperLogLog :: Lens' t (HyperLogLog p)
- size :: ReifiesConfig p => HyperLogLog p -> Approximate Int64
- insert :: (ReifiesConfig s, Hashable a) => a -> HyperLogLog s -> HyperLogLog s
- intersectionSize :: ReifiesConfig p => [HyperLogLog p] -> Approximate Int64
- cast :: forall p q. (ReifiesConfig p, ReifiesConfig q) => HyperLogLog p -> Maybe (HyperLogLog q)
HyperLogLog
newtype HyperLogLog p Source
Initialize a new counter:
>>>
mempty :: HyperLogLog $(3)
HyperLogLog {runHyperLogLog = fromList [0,0,0,0,0,0,0,0]}
Please note how you specify a counter size with the $(n)
invocation. Sizes of up to 16 are valid, with 7 being a
likely good minimum for decent accuracy.
Let's count a list of unique items and get the latest estimate:
>>>
size (foldr insert mempty [1..10] :: HyperLogLog $(4))
Approximate {_confidence = 0.9972, _lo = 2, _estimate = 11, _hi = 20}
Note how insert
can be used to add new observations to the
approximate counter.
HasHyperLogLog k (HyperLogLog k p0) p0 | |
Eq (HyperLogLog k p) | |
Show (HyperLogLog k p) | |
Generic (HyperLogLog k p) | |
ReifiesConfig p => Monoid (HyperLogLog * p) | |
Serialize (HyperLogLog k p) | |
Semigroup (HyperLogLog k p) | |
ReifiesConfig p => HasConfig (HyperLogLog * p) |
class HasHyperLogLog t p | t -> p whereSource
hyperLogLog :: Lens' t (HyperLogLog p)Source
HasHyperLogLog k (HyperLogLog k p0) p0 |
size :: ReifiesConfig p => HyperLogLog p -> Approximate Int64Source
Approximate size of our set
insert :: (ReifiesConfig s, Hashable a) => a -> HyperLogLog s -> HyperLogLog sSource
intersectionSize :: ReifiesConfig p => [HyperLogLog p] -> Approximate Int64Source
cast :: forall p q. (ReifiesConfig p, ReifiesConfig q) => HyperLogLog p -> Maybe (HyperLogLog q)Source