cern.jet.stat.tdouble.quantile

Class ExactDoubleQuantileFinder

java.lang.Object

cern.colt.PersistentObject

cern.jet.stat.tdouble.quantile.ExactDoubleQuantileFinder

All Implemented Interfaces:

DoubleQuantileFinder, Serializable, Cloneable

public class ExactDoubleQuantileFinder
extends PersistentObject
implements DoubleQuantileFinder

Exact quantile finding algorithm for known and unknown N requiring large main memory; computes quantiles over a sequence of double elements. The folkore algorithm: Keeps all elements in main memory, sorts the list, then picks the quantiles.

Version:

1.0, 09/24/99

Author:

wolfgang.hoschek@cern.ch

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
DoubleArrayList	buffer
boolean	isSorted

Constructor Summary

Constructors

Constructor and Description
ExactDoubleQuantileFinder() Constructs an empty exact quantile finder.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(double value) Adds a value to the receiver.
void	addAllOf(DoubleArrayList values) Adds all values of the specified list to the receiver.
void	addAllOfFromTo(DoubleArrayList values, int from, int to) Adds the part of the specified list between indexes from (inclusive) and to (inclusive) to the receiver.
void	clear() Removes all elements from the receiver.
Object	clone() Returns a deep copy of the receiver.
boolean	contains(double element) Returns whether the specified element is contained in the receiver.
boolean	forEach(DoubleProcedure procedure) Applies a procedure to each element of the receiver, if any.
long	memory() Returns the number of elements currently needed to store all contained elements.
double	phi(double element) Returns how many percent of the elements contained in the receiver are <= element.
DoubleArrayList	quantileElements(DoubleArrayList phis) Computes the specified quantile elements over the values previously added.
long	size() Returns the number of elements currently contained in the receiver (identical to the number of values added so far).
String	toString() Returns a String representation of the receiver.
long	totalMemory() Returns the number of elements currently needed to store all contained elements.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

buffer

public DoubleArrayList buffer

isSorted

public boolean isSorted

Constructor Detail

ExactDoubleQuantileFinder

public ExactDoubleQuantileFinder()

Constructs an empty exact quantile finder.

Method Detail

add

public void add(double value)

Adds a value to the receiver.

Specified by:

add in interface DoubleQuantileFinder

Parameters:

value - the value to add.

addAllOf

public void addAllOf(DoubleArrayList values)

Adds all values of the specified list to the receiver.

Specified by:

addAllOf in interface DoubleQuantileFinder

Parameters:

values - the list of which all values shall be added.

addAllOfFromTo

public void addAllOfFromTo(DoubleArrayList values,
                  int from,
                  int to)

Adds the part of the specified list between indexes from (inclusive) and to (inclusive) to the receiver.

Specified by:

addAllOfFromTo in interface DoubleQuantileFinder

Parameters:

values - the list of which elements shall be added.

from - the index of the first element to be added (inclusive).

to - the index of the last element to be added (inclusive).

clear

public void clear()

Removes all elements from the receiver. The receiver will be empty after this call returns, and its memory requirements will be close to zero.

Specified by:

clear in interface DoubleQuantileFinder

clone

public Object clone()

Returns a deep copy of the receiver.

Specified by:

clone in interface DoubleQuantileFinder

Overrides:

clone in class PersistentObject

Returns:

a deep copy of the receiver.

contains

public boolean contains(double element)

Returns whether the specified element is contained in the receiver.

forEach

public boolean forEach(DoubleProcedure procedure)

Applies a procedure to each element of the receiver, if any. Iterates over the receiver in no particular order.

Specified by:

forEach in interface DoubleQuantileFinder

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all elements where iterated over, true otherwise.

memory

public long memory()

Returns the number of elements currently needed to store all contained elements. This number usually differs from the results of method size(), according to the underlying datastructure.

Specified by:

memory in interface DoubleQuantileFinder

phi

public double phi(double element)

Returns how many percent of the elements contained in the receiver are <= element. Does linear interpolation if the element is not contained but lies in between two contained elements.

Specified by:

phi in interface DoubleQuantileFinder

Parameters:

element - the element to search for.

Returns:

the percentage p of elements <= element ( 0.0 <= p <=1.0).

quantileElements

public DoubleArrayList quantileElements(DoubleArrayList phis)

Computes the specified quantile elements over the values previously added.

Specified by:

quantileElements in interface DoubleQuantileFinder

Parameters:

phis - the quantiles for which elements are to be computed. Each phi must be in the interval [0.0,1.0]. phis must be sorted ascending.

Returns:

the exact quantile elements.

size

public long size()

Returns the number of elements currently contained in the receiver (identical to the number of values added so far).

Specified by:

size in interface DoubleQuantileFinder

toString

public String toString()

Returns a String representation of the receiver.

Overrides:

toString in class Object

totalMemory

public long totalMemory()

Returns the number of elements currently needed to store all contained elements. This number usually differs from the results of method size(), according to the underlying datastructure.

Specified by:

totalMemory in interface DoubleQuantileFinder