org.zkoss.pivot.impl.calc
Class VarianceContext

java.lang.Object
  org.zkoss.pivot.impl.calc.VarianceContext

All Implemented Interfaces:

Context<VarianceContext>

public class VarianceContext
extends java.lang.Object
implements Context<VarianceContext>

The context for calculating variance and standard deviation.

Author:

simonpai

Field Summary

protected int	_ncount
protected double	_sqsum
protected double	_sum
static ContextFactory<VarianceContext>	FACTORY

Constructor Summary

VarianceContext()

Method Summary

void	add(java.lang.Object item) Add an item into the aggregation.
int	getNumberCount() Retrieve number count.
double	getSum() Retrieve sum of the numbers.
double	getSumOfSquare() Retrieve sum of the square of the numbers.
java.lang.Double	getVar()
java.lang.Double	getVarP()
void	merge(VarianceContext ctx) Merge from another context of the same type.

Methods inherited from class java.lang.Object

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

Field Detail

_sqsum

protected double _sqsum

_sum

protected double _sum

_ncount

protected int _ncount

FACTORY

public static final ContextFactory<VarianceContext> FACTORY

Constructor Detail

VarianceContext

public VarianceContext()

Method Detail

add

public void add(java.lang.Object item)

Description copied from interface: Context

Add an item into the aggregation.

Specified by:

add in interface Context<VarianceContext>

merge

public void merge(VarianceContext ctx)

Description copied from interface: Context

Merge from another context of the same type.

Specified by:

merge in interface Context<VarianceContext>

getSumOfSquare

public double getSumOfSquare()

Retrieve sum of the square of the numbers.

getSum

public double getSum()

Retrieve sum of the numbers.

getNumberCount

public int getNumberCount()

Retrieve number count. Non-number objects are ignored.

getVar

public java.lang.Double getVar()

getVarP

public java.lang.Double getVarP()