Package org.anchoranalysis.math.arithmetic

Class RunningSum

Object

org.anchoranalysis.math.arithmetic.RunningSum

All Implemented Interfaces:

Serializable

public class RunningSum
extends Object
implements Serializable

Mutable class that allows for incrementing jointly sum and count variables, so as to eventually calculate the mean.

It can also be reset to zero, as needed.

Author:

Owen Feehan

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
RunningSum()
RunningSum(double sum, long count)

Method Summary

Modifier and Type	Method	Description
void	add(RunningSum toAdd)	Adds the values of another RunningSum to the current values.
RunningSum	duplicate()	Deep-copy.
long	getCount()	The running count.
double	getSum()	The running sum.
void	increment(double sumIncrement)	Adds a new item to the sum, and increments the count by 1.
void	increment(double sumIncrement, long countIncrement)	Increments both the sum and count by particular values.
void	increment(RunningSum runningSum)	Increments (adds) an existing RunningSum to the current.
double	mean()	Calculates the mean.
double	mean(double valueIfCountZero)	Calculates the mean.
double	meanAndReset()	Calculate the mean and then reset to zero.
void	reset()	Reset the sum and count to zero.

Methods inherited from class java.lang.Object

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

Constructor Details

RunningSum

public RunningSum()

RunningSum

public RunningSum(double sum, long count)

Method Details

mean

public double mean()

Calculates the mean.

Returns:

the mean or NaN if the count is zero.

mean

public double mean(double valueIfCountZero)

Calculates the mean.

Parameters:

valueIfCountZero - value to use if the count is zero.

Returns:

the mean or valueIfCountZero if the count is zero.

meanAndReset

public double meanAndReset()

Calculate the mean and then reset to zero.

Returns:

the mean, before being reset to zero.

reset

public void reset()

Reset the sum and count to zero.

increment

public void increment(double sumIncrement)

Adds a new item to the sum, and increments the count by 1.

Parameters:

sumIncrement - the value to add to sum.

increment

public void increment(double sumIncrement, long countIncrement)

Increments both the sum and count by particular values.

Parameters:

sumIncrement - increment-value for sum.

countIncrement - increment-value for count.

increment

public void increment(RunningSum runningSum)

Increments (adds) an existing RunningSum to the current.

Parameters:

runningSum - the existing sum, which is unmodified.

duplicate

public RunningSum duplicate()

Deep-copy.

Returns:

a new object with new state.

add

public void add(RunningSum toAdd)

Adds the values of another RunningSum to the current values.

Parameters:

toAdd - the other sum that will be added.

getSum

public double getSum()

The running sum.

getCount

public long getCount()

The running count.