org.matheclipse.core.stat.descriptive.summary

Class SymbolicSum

java.lang.Object

org.matheclipse.core.stat.descriptive.AbstractSymbolicStorelessUnivariateStatistic

org.matheclipse.core.stat.descriptive.summary.SymbolicSum

All Implemented Interfaces:

java.io.Serializable, StorelessSymbolicUnivariateStatistic, SymbolicUnivariateStatistic

public class SymbolicSum
extends AbstractSymbolicStorelessUnivariateStatistic
implements java.io.Serializable

Returns the sum of the available values.

If there are no values in the dataset, then null is returned.

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:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SymbolicSum() Create a Sum instance

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the internal state of the Statistic
IExpr	evaluate(IAST values, IAST weights) The weighted sum of the entries in the the input array.
IExpr	evaluate(IAST values, IAST weights, int begin, int length) The weighted sum of the entries in the specified portion of the input array, or 0 if the designated subarray is empty.
IExpr	evaluate(IAST values, int begin, int length) The sum of the entries in the specified portion of the input array, or 0 if the designated subarray is empty.
long	getN() Returns the number of values that have been added.
IExpr	getResult() Returns the current value of the Statistic.
void	increment(IExpr d) Updates the internal state of the statistic to reflect the addition of the new value.

Methods inherited from class org.matheclipse.core.stat.descriptive.AbstractSymbolicStorelessUnivariateStatistic

evaluate, incrementAll, incrementAll, test, test, test, test

Methods inherited from class java.lang.Object

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

Constructor Detail

SymbolicSum

public SymbolicSum()

Create a Sum instance

Method Detail

increment

public void increment(IExpr d)

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

Specified by:

increment in interface StorelessSymbolicUnivariateStatistic

Specified by:

increment in class AbstractSymbolicStorelessUnivariateStatistic

Parameters:

d - the new value.

getResult

public IExpr getResult()

Returns the current value of the Statistic.

Specified by:

getResult in interface StorelessSymbolicUnivariateStatistic

Specified by:

getResult in class AbstractSymbolicStorelessUnivariateStatistic

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 StorelessSymbolicUnivariateStatistic

Specified by:

getN in class AbstractSymbolicStorelessUnivariateStatistic

Returns:

the number of values.

clear

public void clear()

Clears the internal state of the Statistic

Specified by:

clear in interface StorelessSymbolicUnivariateStatistic

Specified by:

clear in class AbstractSymbolicStorelessUnivariateStatistic

evaluate

public IExpr evaluate(IAST values,
                      int begin,
                      int length)

The sum of the entries in the specified portion of the input array, or 0 if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

Specified by:

evaluate in interface SymbolicUnivariateStatistic

Overrides:

evaluate in class AbstractSymbolicStorelessUnivariateStatistic

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 values or 0 if length = 0

Throws:

java.lang.IllegalArgumentException - if the array is null or the array index parameters are not valid

See Also:

UnivariateStatistic.evaluate(double[], int, int)

evaluate

public IExpr evaluate(IAST values,
                      IAST weights,
                      int begin,
                      int length)

The weighted sum of the entries in the specified portion of the input array, or 0 if the designated subarray is empty.

Throws IllegalArgumentException if any of the following are true:

• the values array is null
• the weights array is null
• the weights array does not have the same length as the values array
• the weights array contains one or more infinite values
• the weights array contains one or more NaN values
• the weights array contains negative values
• the start and length arguments do not determine a valid array

Uses the formula,

    weighted sum = Σ(values[i] * weights[i])
 

Parameters:

values - the input array

weights - the weights array

begin - index of the first array element to include

length - the number of elements to include

Returns:

the sum of the values or 0 if length = 0

Throws:

java.lang.IllegalArgumentException - if the parameters are not valid

Since:

2.1

evaluate

public IExpr evaluate(IAST values,
                      IAST weights)

The weighted sum of the entries in the the input array.

Throws IllegalArgumentException if any of the following are true:

• the values array is null
• the weights array is null
• the weights array does not have the same length as the values array
• the weights array contains one or more infinite values
• the weights array contains one or more NaN values
• the weights array contains negative values

Uses the formula,

    weighted sum = Σ(values[i] * weights[i])
 

Parameters:

values - the input array

weights - the weights array

Returns:

the sum of the values or Double.NaN if length = 0

Throws:

java.lang.IllegalArgumentException - if the parameters are not valid

Since:

2.1