org.apache.commons.math3.stat.descriptive.summary.SumOfLogs

All Implemented Interfaces:: Serializable, StorelessUnivariateStatistic, UnivariateStatistic, MathArrays.Function

public class SumOfLogs extends AbstractStorelessUnivariateStatistic implements Serializable

Returns the sum of the natural logs for this collection of values.

Uses FastMath.log(double) to compute the logs. Therefore,

If any of values are < 0, the result is NaN.
If all values are non-negative and less than Double.POSITIVE_INFINITY, but at least one value is 0, the result is Double.NEGATIVE_INFINITY.
If both Double.POSITIVE_INFINITY and Double.NEGATIVE_INFINITY are among the values, the result is NaN.

Note that this implementation is not synchronized. If multiple threads access an instance of this class concurrently, and at least one of the threads invokes the increment() or clear() method, it must be synchronized externally.

See Also:

Constructor Summary

Constructors

Constructor

Description

SumOfLogs()

Create a SumOfLogs instance

SumOfLogs(SumOfLogs original)

Copy constructor, creates a new SumOfLogs identical to the original
Method Summary

Modifier and Type

Method

Description

void

clear()

Clears the internal state of the Statistic

SumOfLogs

copy()

Returns a copy of the statistic with the same internal state.

static void

copy(SumOfLogs source, SumOfLogs dest)

Copies source to dest.

double

evaluate(double[] values, int begin, int length)

Returns the sum of the natural logs of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

long

getN()

Returns the number of values that have been added.

double

getResult()

Returns the current value of the Statistic.

void

increment(double d)

Updates the internal state of the statistic to reflect the addition of the new value.

Methods inherited from class org.apache.commons.math3.stat.descriptive.AbstractStorelessUnivariateStatistic
equals, evaluate, hashCode, incrementAll, incrementAll

Methods inherited from class org.apache.commons.math3.stat.descriptive.AbstractUnivariateStatistic
evaluate, getData, getDataRef, setData, setData, test, test, test, test

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

Constructor Details
- SumOfLogs
  
  public SumOfLogs()
  
  Create a SumOfLogs instance
- SumOfLogs
  
  public SumOfLogs(SumOfLogs original) throws NullArgumentException
  
  Copy constructor, creates a new SumOfLogs identical to the original
  
  Parameters:
  
  original - the SumOfLogs instance to copy
  
  Throws:
  
  NullArgumentException - if original is null
Method Details
- increment
  
  public void increment(double d)
  
  Updates the internal state of the statistic to reflect the addition of the new value.
  
  Specified by:
  
  increment in interface StorelessUnivariateStatistic
  
  Specified by:
  
  increment in class AbstractStorelessUnivariateStatistic
  
  Parameters:
  
  d - the new value.
- getResult
  
  public double getResult()
  
  Returns the current value of the Statistic.
  
  Specified by:
  
  getResult in interface StorelessUnivariateStatistic
  
  Specified by:
  
  getResult in class AbstractStorelessUnivariateStatistic
  
  Returns:
  
  value of the statistic, Double.NaN if it has been cleared or just instantiated.
- getN
  
  public long getN()
  
  Returns the number of values that have been added.
  
  Specified by:
  
  getN in interface StorelessUnivariateStatistic
  
  Returns:
  
  the number of values.
- clear
  
  public void clear()
  
  Clears the internal state of the Statistic
  
  Specified by:
  
  clear in interface StorelessUnivariateStatistic
  
  Specified by:
  
  clear in class AbstractStorelessUnivariateStatistic
- evaluate
  
  public double evaluate(double[] values, int begin, int length) throws MathIllegalArgumentException
  
  Returns the sum of the natural logs of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.
  Throws MathIllegalArgumentException if the array is null.
  
  See SumOfLogs.
  Specified by:
  
  evaluate in interface MathArrays.Function
  
  Specified by:
  
  evaluate in interface UnivariateStatistic
  
  Overrides:
  
  evaluate in class AbstractStorelessUnivariateStatistic
  
  Parameters:
  
  values - the input array
  
  begin - index of the first array element to include
  
  length - the number of elements to include
  
  Returns:
  
  the sum of the natural logs of the values or 0 if length = 0
  
  Throws:
  
  MathIllegalArgumentException - if the array is null or the array index parameters are not valid
  
  See Also:
  
  UnivariateStatistic.evaluate(double[], int, int)
- copy
  
  public SumOfLogs copy()
  
  Returns a copy of the statistic with the same internal state.
  
  Specified by:
  
  copy in interface StorelessUnivariateStatistic
  
  Specified by:
  
  copy in interface UnivariateStatistic
  
  Specified by:
  
  copy in class AbstractStorelessUnivariateStatistic
  
  Returns:
  
  a copy of the statistic
- copy
  
  public static void copy(SumOfLogs source, SumOfLogs dest) throws NullArgumentException
  
  Copies source to dest.
  Neither source nor dest can be null.
  
  Parameters:
  
  source - SumOfLogs to copy
  
  dest - SumOfLogs to copy to
  
  Throws:
  
  NullArgumentException - if either source or dest is null

Class SumOfLogs

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.math3.stat.descriptive.AbstractStorelessUnivariateStatistic

Methods inherited from class org.apache.commons.math3.stat.descriptive.AbstractUnivariateStatistic

Methods inherited from class java.lang.Object

Constructor Details

SumOfLogs

SumOfLogs

Method Details

increment

getResult

getN

clear

evaluate

copy

copy