org.grouplens.lenskit.util.statistics

Class MeanAccumulator

java.lang.Object

org.grouplens.lenskit.util.statistics.MeanAccumulator

public class MeanAccumulator
extends Object

Accumulate a mean. Only the sum and the item count is stored, not the values themselves.

Since:

0.11

Constructor Summary

Constructors

Constructor and Description
MeanAccumulator() Construct a new, zeroed average accumulator.
MeanAccumulator(double sum, long count) Initialize the MeanAccumulator with a pre-calculated sum and the amount of values included.

Method Summary

Modifier and Type	Method and Description
void	add(double datum) Add a new datum to the MeanAccumulator.
long	getCount()
double	getMean()
double	getTotal() Get the total of the values accumulated so far.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MeanAccumulator

public MeanAccumulator()

Construct a new, zeroed average accumulator.

MeanAccumulator

public MeanAccumulator(double sum,
                       long count)

Initialize the MeanAccumulator with a pre-calculated sum and the amount of values included.

Parameters:

sum - pre-calculated sum

count - amount of values that where used to build this sum

Method Detail

add

public void add(double datum)

Add a new datum to the MeanAccumulator.

Parameters:

datum - new datum to include into the average.

getMean

public double getMean()

Returns:

average over all added datums

getTotal

public double getTotal()

Get the total of the values accumulated so far.

Returns:

The total of the values.

getCount

public long getCount()

Returns:

amount of values this average is based on

toString

public String toString()

Overrides:

toString in class Object