SynchronizedDescriptiveStatistics

java.lang.Object
- org.apache.openejb.math.stat.descriptive.DescriptiveStatistics
- - org.apache.openejb.math.stat.descriptive.SynchronizedDescriptiveStatistics

All Implemented Interfaces:

java.io.Serializable, StatisticalSummary
```
public class SynchronizedDescriptiveStatistics
extends DescriptiveStatistics
```
Implementation of DescriptiveStatistics that is safe to use in a multithreaded environment. Multiple threads can safely operate on a single instance without causing runtime exceptions due to race conditions. In effect, this implementation makes modification and access methods atomic operations for a single instance. That is to say, as one thread is computing a statistic from the instance, no other thread can modify the instance nor compute another statistic.

Since:

1.2

See Also:

Serialized Form

Field Summary
- Fields inherited from class org.apache.openejb.math.stat.descriptive.DescriptiveStatistics
  eDA, INFINITE_WINDOW, windowSize

Constructor Summary

Constructors
Constructor and Description
`SynchronizedDescriptiveStatistics()` Construct an instance with infinite window
`SynchronizedDescriptiveStatistics(int window)` Construct an instance with finite window
`SynchronizedDescriptiveStatistics(SynchronizedDescriptiveStatistics original)` A copy constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addValue(double v)` Adds the value to the dataset.
`double`	`apply(UnivariateStatistic stat)` Apply the given statistic to the data associated with this set of statistics.
`void`	`clear()` Resets all statistics and storage
`SynchronizedDescriptiveStatistics`	`copy()` Returns a copy of this SynchronizedDescriptiveStatistics instance with the same internal state.
`static void`	`copy(SynchronizedDescriptiveStatistics source, SynchronizedDescriptiveStatistics dest)` Copies source to dest.
`double`	`getElement(int index)` Returns the element at the specified index
`long`	`getN()` Returns the number of available values
`double`	`getStandardDeviation()` Returns the standard deviation of the available values.
`double[]`	`getValues()` Returns the current set of values in an array of double primitives.
`int`	`getWindowSize()` Returns the maximum number of values that can be stored in the dataset, or INFINITE_WINDOW (-1) if there is no limit.
`void`	`setWindowSize(int windowSize)` WindowSize controls the number of values which contribute to the reported statistics.
`java.lang.String`	`toString()` Generates a text report displaying univariate statistics from values that have been added.

Methods inherited from class org.apache.openejb.math.stat.descriptive.DescriptiveStatistics
copy, getGeometricMean, getGeometricMeanImpl, getKurtosis, getKurtosisImpl, getMax, getMaxImpl, getMean, getMeanImpl, getMin, getMinImpl, getPercentile, getPercentileImpl, getSkewness, getSkewnessImpl, getSortedValues, getSum, getSumImpl, getSumsq, getSumsqImpl, getVariance, getVarianceImpl, removeMostRecentValue, replaceMostRecentValue, setGeometricMeanImpl, setKurtosisImpl, setMaxImpl, setMeanImpl, setMinImpl, setPercentileImpl, setSkewnessImpl, setSumImpl, setSumsqImpl, setVarianceImpl

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - SynchronizedDescriptiveStatistics
```
public SynchronizedDescriptiveStatistics()
```
    Construct an instance with infinite window
  - SynchronizedDescriptiveStatistics
```
public SynchronizedDescriptiveStatistics(int window)
```
    Construct an instance with finite window
    
    Parameters:
    
    window - the finite window size.
  - SynchronizedDescriptiveStatistics
```
public SynchronizedDescriptiveStatistics(SynchronizedDescriptiveStatistics original)
```
    A copy constructor. Creates a deep-copy of the original.
    
    Parameters:
    
    original - the SynchronizedDescriptiveStatistics instance to copy
- Method Detail
  - addValue
```
public void addValue(double v)
```
    Adds the value to the dataset. If the dataset is at the maximum size (i.e., the number of stored elements equals the currently configured windowSize), the first (oldest) element in the dataset is discarded to make room for the new value.
    
    Overrides:
    
    addValue in class DescriptiveStatistics
    
    Parameters:
    
    v - the value to be added
  - apply
```
public double apply(UnivariateStatistic stat)
```
    Apply the given statistic to the data associated with this set of statistics.
    
    Overrides:
    
    apply in class DescriptiveStatistics
    
    Parameters:
    
    stat - the statistic to apply
    
    Returns:
    
    the computed value of the statistic.
  - clear
```
public void clear()
```
    Resets all statistics and storage
    
    Overrides:
    
    clear in class DescriptiveStatistics
  - getElement
```
public double getElement(int index)
```
    Returns the element at the specified index
    
    Overrides:
    
    getElement in class DescriptiveStatistics
    
    Parameters:
    
    index - The Index of the element
    
    Returns:
    
    return the element at the specified index
  - getN
```
public long getN()
```
    Returns the number of available values
    
    Specified by:
    
    getN in interface StatisticalSummary
    
    Overrides:
    
    getN in class DescriptiveStatistics
    
    Returns:
    
    The number of available values
  - getStandardDeviation
```
public double getStandardDeviation()
```
    Returns the standard deviation of the available values.
    
    Specified by:
    
    getStandardDeviation in interface StatisticalSummary
    
    Overrides:
    
    getStandardDeviation in class DescriptiveStatistics
    
    Returns:
    
    The standard deviation, Double.NaN if no values have been added or 0.0 for a single value set.
  - getValues
```
public double[] getValues()
```
    Returns the current set of values in an array of double primitives. The order of addition is preserved. The returned array is a fresh copy of the underlying data -- i.e., it is not a reference to the stored data.
    
    Overrides:
    
    getValues in class DescriptiveStatistics
    
    Returns:
    
    returns the current set of numbers in the order in which they were added to this set
  - getWindowSize
```
public int getWindowSize()
```
    Returns the maximum number of values that can be stored in the dataset, or INFINITE_WINDOW (-1) if there is no limit.
    
    Overrides:
    
    getWindowSize in class DescriptiveStatistics
    
    Returns:
    
    The current window size or -1 if its Infinite.
  - setWindowSize
```
public void setWindowSize(int windowSize)
```
    WindowSize controls the number of values which contribute to the reported statistics. For example, if windowSize is set to 3 and the values {1,2,3,4,5} have been added in that order then the available values are {3,4,5} and all reported statistics will be based on these values
    
    Overrides:
    
    setWindowSize in class DescriptiveStatistics
    
    Parameters:
    
    windowSize - sets the size of the window.
  - toString
```
public java.lang.String toString()
```
    Generates a text report displaying univariate statistics from values that have been added. Each statistic is displayed on a separate line.
    
    Overrides:
    
    toString in class DescriptiveStatistics
    
    Returns:
    
    String with line feeds displaying statistics
  - copy
```
public SynchronizedDescriptiveStatistics copy()
```
    Returns a copy of this SynchronizedDescriptiveStatistics instance with the same internal state.
    
    Overrides:
    
    copy in class DescriptiveStatistics
    
    Returns:
    
    a copy of this
  - copy
```
public static void copy(SynchronizedDescriptiveStatistics source,
                        SynchronizedDescriptiveStatistics dest)
```
    Copies source to dest.
    Neither source nor dest can be null.
    
    Acquires synchronization lock on source, then dest before copying.
    
    Parameters:
    
    source - SynchronizedDescriptiveStatistics to copy
    
    dest - SynchronizedDescriptiveStatistics to copy to
    
    Throws:
    
    java.lang.NullPointerException - if either source or dest is null

Class SynchronizedDescriptiveStatistics

Field Summary

Fields inherited from class org.apache.openejb.math.stat.descriptive.DescriptiveStatistics

Constructor Summary

Method Summary

Methods inherited from class org.apache.openejb.math.stat.descriptive.DescriptiveStatistics

Methods inherited from class java.lang.Object

Constructor Detail

SynchronizedDescriptiveStatistics

SynchronizedDescriptiveStatistics

SynchronizedDescriptiveStatistics

Method Detail

addValue

apply

clear

getElement

getN

getStandardDeviation

getValues

getWindowSize

setWindowSize

toString

copy

copy