org.apache.cassandra.utils

Class StreamingHistogram

java.lang.Object

org.apache.cassandra.utils.StreamingHistogram

public class StreamingHistogram
extends java.lang.Object

Histogram that can be constructed from streaming of data. The algorithm is taken from following paper: Yael Ben-Haim and Elad Tom-Tov, "A Streaming Parallel Decision Tree Algorithm" (2010) http://jmlr.csail.mit.edu/papers/volume11/ben-haim10a/ben-haim10a.pdf

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StreamingHistogram.StreamingHistogramBuilder
static class	StreamingHistogram.StreamingHistogramSerializer

Field Summary

Fields

Modifier and Type	Field and Description
static StreamingHistogram.StreamingHistogramSerializer	serializer

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
java.util.Map<java.lang.Double,java.lang.Long>	getAsMap()
int	hashCode()
double	sum(double b) Calculates estimated number of points in interval [-inf,b].

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

serializer

public static final StreamingHistogram.StreamingHistogramSerializer serializer

Method Detail

sum

public double sum(double b)

Calculates estimated number of points in interval [-inf,b].

Parameters:

b - upper bound of a interval to calculate sum

Returns:

estimated number of points in a interval [-inf,b].

getAsMap

public java.util.Map<java.lang.Double,java.lang.Long> getAsMap()

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object