com.twitter.scalding.typed

CumulativeSum

object CumulativeSum

Extension for TypedPipe to add a cumulativeSum method. Given a TypedPipe with T = (GroupField, (SortField, SummableField)) cumulaitiveSum will return a SortedGrouped with the SummableField accumulated according to the sort field. eg: ('San Francisco', (100, 100)), ('San Francisco', (101, 50)), ('San Francisco', (200, 200)), ('Vancouver', (100, 50)), ('Vancouver', (101, 300)), ('Vancouver', (200, 100)) becomes ('San Francisco', (100, 100)), ('San Francisco', (101, 150)), ('San Francisco', (200, 300)), ('Vancouver', (100, 50)), ('Vancouver', (101, 350)), ('Vancouver', (200, 450))

If you provide cumulativeSum a partition function you get the same result but you allow for more than one reducer per group. This is useful for when you have a single group that has a very large number of entries. For example in the previous example if you gave a partition function of the form { _ / 100 } then you would never have any one reducer deal with more than 2 entries.

Linear Supertypes
AnyRef, Any
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. CumulativeSum
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Type Members

  1. class CumulativeSumExtension[K, U, V] extends AnyRef

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any
  6. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  7. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  8. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  9. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  10. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  11. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  12. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  13. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  14. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  15. final def notify(): Unit

    Definition Classes
    AnyRef
  16. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  17. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  18. implicit def toCumulativeSum[K, U, V](pipe: TypedPipe[(K, (U, V))]): CumulativeSumExtension[K, U, V]

  19. def toString(): String

    Definition Classes
    AnyRef → Any
  20. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  21. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  22. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped