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com.twitter.algebird

TopPctCMSMonoid

class TopPctCMSMonoid[K] extends TopCMSMonoid[K]

Monoid for Top-% based TopCMS sketches.

Usage

The type K is the type of items you want to count. You must provide an implicit CMSHasher[K] for K, and Algebird ships with several such implicits for commonly used types such as Long and BigInt.

If your type K is not supported out of the box, you have two options: 1) You provide a "translation" function to convert items of your (unsupported) type K to a supported type such as Double, and then use the contramap function of CMSHasher to create the required CMSHasher[K] for your type (see the documentation of CMSHasher for an example); 2) You implement a CMSHasher[K] from scratch, using the existing CMSHasher implementations as a starting point.

Note: Because Arrays in Scala/Java not have sane equals and hashCode implementations, you cannot safely use types such as Array[Byte]. Extra work is required for Arrays. For example, you may opt to convert Array[T] to a Seq[T] via toSeq, or you can provide appropriate wrapper classes. Algebird provides one such wrapper class, Bytes, to safely wrap an Array[Byte] for use with CMS.

K

The type used to identify the elements to be counted. For example, if you want to count the occurrence of user names, you could map each username to a unique numeric ID expressed as a Long, and then count the occurrences of those Longs with a CMS of type K=Long. Note that this mapping between the elements of your problem domain and their identifiers used for counting via CMS should be bijective. We require a CMSHasher context bound for K, see CMSHasher for available implicits that can be imported. Which type K should you pick in practice? For domains that have less than 2^64 unique elements, you'd typically use Long. For larger domains you can try BigInt, for example.

Linear Supertypes
TopCMSMonoid[K], Monoid[TopCMS[K]], AdditiveMonoid[TopCMS[K]], cats.kernel.Monoid[TopCMS[K]], Semigroup[TopCMS[K]], AdditiveSemigroup[TopCMS[K]], cats.kernel.Semigroup[TopCMS[K]], Serializable, AnyRef, Any
Ordering
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Inherited
  1. TopPctCMSMonoid
  2. TopCMSMonoid
  3. Monoid
  4. AdditiveMonoid
  5. Monoid
  6. Semigroup
  7. AdditiveSemigroup
  8. Semigroup
  9. Serializable
  10. AnyRef
  11. Any
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Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new TopPctCMSMonoid(cms: CMS[K], heavyHittersPct: Double = 0.01)

    cms

    A CMS instance, which is used for the counting and the frequency estimation performed by this class.

    heavyHittersPct

    A threshold for finding heavy hitters, i.e., elements that appear at least (heavyHittersPct * totalCount) times in the stream.

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def additive: algebra.Monoid[TopCMS[K]]

    These are from algebra.Monoid

    These are from algebra.Monoid

    Definition Classes
    Monoid → AdditiveMonoid → Semigroup → AdditiveSemigroup
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def assertNotZero(v: TopCMS[K]): Unit
    Definition Classes
    Monoid
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  8. def combine(l: TopCMS[K], r: TopCMS[K]): TopCMS[K]
    Definition Classes
    Semigroup → Semigroup
  9. def combineAll(t: TraversableOnce[TopCMS[K]]): TopCMS[K]
    Definition Classes
    Monoid → Monoid
  10. def combineAllOption(as: IterableOnce[TopCMS[K]]): Option[TopCMS[K]]
    Definition Classes
    Monoid → Semigroup
  11. def combineN(a: TopCMS[K], n: Int): TopCMS[K]
    Definition Classes
    Monoid → Semigroup
  12. def create(data: Seq[K]): TopCMS[K]

    Creates a sketch out of multiple items.

    Creates a sketch out of multiple items.

    Definition Classes
    TopCMSMonoid
  13. def create(item: K): TopCMS[K]

    Creates a sketch out of a single item.

    Creates a sketch out of a single item.

    Definition Classes
    TopCMSMonoid
  14. def empty: TopCMS[K]
    Definition Classes
    Monoid → Monoid
  15. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  16. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  17. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  18. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  19. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  20. def isEmpty(a: TopCMS[K])(implicit ev: Eq[TopCMS[K]]): Boolean
    Definition Classes
    Monoid
  21. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  22. def isNonZero(v: TopCMS[K]): Boolean
    Definition Classes
    Monoid
  23. def isZero(a: TopCMS[K])(implicit ev: Eq[TopCMS[K]]): Boolean
    Definition Classes
    AdditiveMonoid
  24. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  25. def nonZeroOption(v: TopCMS[K]): Option[TopCMS[K]]
    Definition Classes
    Monoid
  26. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  27. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  28. val params: TopCMSParams[K]
    Definition Classes
    TopCMSMonoid
  29. def plus(left: TopCMS[K], right: TopCMS[K]): TopCMS[K]

    Combines the two sketches.

    Combines the two sketches.

    The sketches must use the same hash functions.

    Definition Classes
    TopCMSMonoid → AdditiveSemigroup
  30. def positiveSumN(a: TopCMS[K], n: Int): TopCMS[K]
    Attributes
    protected[this]
    Definition Classes
    AdditiveSemigroup
  31. def repeatedCombineN(a: TopCMS[K], n: Int): TopCMS[K]
    Attributes
    protected[this]
    Definition Classes
    Semigroup
  32. def sum(sketches: TraversableOnce[TopCMS[K]]): TopCMS[K]
    Definition Classes
    TopCMSMonoid → Monoid → AdditiveMonoid
  33. def sumN(a: TopCMS[K], n: Int): TopCMS[K]
    Definition Classes
    AdditiveMonoid → AdditiveSemigroup
  34. def sumOption(sketches: TraversableOnce[TopCMS[K]]): Option[TopCMS[K]]

    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].

    returns

    None if iter is empty, else an option value containing the summed T

    Definition Classes
    TopCMSMonoid → Semigroup
    Note

    Override if there is a faster way to compute this sum than iter.reduceLeftOption using plus.

  35. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  36. def toString(): String
    Definition Classes
    AnyRef → Any
  37. def trySum(as: TraversableOnce[TopCMS[K]]): Option[TopCMS[K]]
    Definition Classes
    AdditiveMonoid → AdditiveSemigroup
  38. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  39. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  40. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  41. val zero: TopCMS[K]
    Definition Classes
    TopCMSMonoid → AdditiveMonoid

Inherited from TopCMSMonoid[K]

Inherited from Monoid[TopCMS[K]]

Inherited from AdditiveMonoid[TopCMS[K]]

Inherited from cats.kernel.Monoid[TopCMS[K]]

Inherited from Semigroup[TopCMS[K]]

Inherited from AdditiveSemigroup[TopCMS[K]]

Inherited from cats.kernel.Semigroup[TopCMS[K]]

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped