Class SampleManager

java.lang.Object
  SampleManager

public class SampleManager
extends java.lang.Object

SampleManager keeps track of aggregate information about your data samples: minimum and maximum values and estimates of arithmetic mean, variance, and standard deviation. It requires constant space independently of the number of samples added.

Field Summary

protected double	lag1sum
protected double	lastSample
protected double	max
protected double	min
protected int	nextValPos
protected int	numSamples
protected long	seed
protected double	stdDev
protected double	sumX
protected double	sumXSquared
protected double	variance
protected double	xbar

Constructor Summary

SampleManager()
Constructs a new SampleManager instance.

Method Summary

void	addSample(double sample) Records a sample value, updating sample count, min and max values, and mean and variance estimates.
double	getMax() Returns the maximum value seen so far.
double	getMean() Returns the arithmetic mean of sample values seen so far.
double	getMin() Returns the minimum value seen so far.
double	getStdDev() Returns the standard deviation of sample values seen so far.
double	getVariance() Returns the variance of sample values seen so far.
int	numSamples() Returns the number of sample values seen so far.
protected void	updateEstimates(double sample)

Methods inherited from class java.lang.Object

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

Field Detail

numSamples

protected int numSamples

sumX

protected double sumX

sumXSquared

protected double sumXSquared

xbar

protected double xbar

variance

protected double variance

stdDev

protected double stdDev

seed

protected long seed

max

protected double max

min

protected double min

lag1sum

protected double lag1sum

lastSample

protected double lastSample

nextValPos

protected int nextValPos

Constructor Detail

SampleManager

public SampleManager()

Constructs a new SampleManager instance.

Method Detail

updateEstimates

protected final void updateEstimates(double sample)

addSample

public final void addSample(double sample)

Records a sample value, updating sample count, min and max values, and mean and variance estimates.

Parameters:

sample - the sample to record.

numSamples

public final int numSamples()

Returns the number of sample values seen so far.

Returns:

the number of sample values seen so far

getMean

public final double getMean()

Returns the arithmetic mean of sample values seen so far.

Returns:

the mean of sample values seen so far

getVariance

public final double getVariance()

Returns the variance of sample values seen so far.

Returns:

the variance of sample values seen so far

getStdDev

public final double getStdDev()

Returns the standard deviation of sample values seen so far.

Returns:

the standard deviation of sample values seen so far

getMax

public final double getMax()

Returns the maximum value seen so far.

Returns:

the maximum value seen so far

getMin

public final double getMin()

Returns the minimum value seen so far.

Returns:

the minimum value seen so far