Packages

t

com.twitter.algebird

CMSCounting

trait CMSCounting[K, C[_]] extends AnyRef

A trait for CMS implementations that can count elements in a data stream and that can answer point queries (i.e. frequency estimates) for these elements.

Known implementations: CMS, TopCMS.

K

The type used to identify the elements to be counted.

C

The type of the actual CMS that implements this trait.

Linear Supertypes
AnyRef, Any
Known Subclasses
CMS, CMSInstance, CMSItem, CMSZero, SparseCMS, TopCMS, TopCMSInstance, TopCMSItem, TopCMSZero
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Abstract Value Members

  1. abstract def +(item: K, count: Long): C[K]

    Counts the item count times and returns the result as a new sketch.

  2. abstract def ++(other: C[K]): C[K]

    Returns a new sketch that is the combination of this sketch and the other sketch.

  3. abstract def delta: Double

    Returns the bound on the probability that a query estimate does NOT lie within some small interval (an interval that depends on eps) around the truth.

  4. abstract def eps: Double

    Returns the one-sided error bound on the error of each point query, i.e.

    Returns the one-sided error bound on the error of each point query, i.e. frequency estimate.

  5. abstract def f2: Approximate[Long]

    The second frequency moment is \sum a_i^2, where a_i is the count of the i-th element.

  6. abstract def frequency(item: K): Approximate[Long]

    Returns an estimate of the total number of times this item has been seen in the stream so far.

    Returns an estimate of the total number of times this item has been seen in the stream so far. This estimate is an upper bound.

    It is always true that estimatedFrequency >= trueFrequency. With probability p >= 1 - delta, it also holds that estimatedFrequency <= trueFrequency + eps * totalCount.

  7. abstract def innerProduct(other: C[K]): Approximate[Long]

    Returns an estimate of the inner product against another data stream.

    Returns an estimate of the inner product against another data stream.

    In other words, let a_i denote the number of times element i has been seen in the data stream summarized by this CMS, and let b_i denote the same for the other CMS. Then this returns an estimate of <a, b> = \sum a_i b_i.

    Note: This can also be viewed as the join size between two relations.

    It is always true that actualInnerProduct <= estimatedInnerProduct. With probability p >= 1 - delta, it also holds that estimatedInnerProduct <= actualInnerProduct + eps * thisTotalCount * otherTotalCount.

  8. abstract def maxExactCountOpt: Option[Int]

    An Option parameter about how many exact counts a sparse CMS wants to keep

  9. abstract def totalCount: Long

    Total number of elements counted (i.e.

    Total number of elements counted (i.e. seen in the data stream) so far.

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. def +(item: K): C[K]

    Counts the item and returns the result as a new sketch.

  4. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def clone(): AnyRef
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  7. def depth: Int

    Number of hash functions (also: number of rows in the counting table).

    Number of hash functions (also: number of rows in the counting table). This number is derived from delta.

  8. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  9. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  10. def f1: Long

    The first frequency moment is the total number of elements in the stream.

  11. def finalize(): Unit
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  12. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
  13. def hashCode(): Int
    Definition Classes
    AnyRef → Any
  14. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  15. def maxExactCount: Int

    Number of exact counts a sparse CMS wants to keep.

    Number of exact counts a sparse CMS wants to keep. This number is derived from maxExactCountOpt.

  16. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  17. final def notify(): Unit
    Definition Classes
    AnyRef
  18. final def notifyAll(): Unit
    Definition Classes
    AnyRef
  19. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  20. def toString(): String
    Definition Classes
    AnyRef → Any
  21. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  22. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  23. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  24. def width: Int

    Number of counters per hash function (also: number of columns in the counting table).

    Number of counters per hash function (also: number of columns in the counting table). This number is derived from eps.

Inherited from AnyRef

Inherited from Any

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