Class Product
- java.lang.Object
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- org.apache.commons.math4.legacy.stat.descriptive.AbstractStorelessUnivariateStatistic
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- org.apache.commons.math4.legacy.stat.descriptive.summary.Product
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- All Implemented Interfaces:
MathArrays.Function,StorelessUnivariateStatistic,UnivariateStatistic,WeightedEvaluation
public class Product extends AbstractStorelessUnivariateStatistic implements WeightedEvaluation
Returns the product of the available values.If there are no values in the dataset, then 1 is returned. If any of the values are
NaN, thenNaNis 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()orclear()method, it must be synchronized externally.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description voidclear()Clears the internal state of the Statistic.Productcopy()Returns a copy of the statistic with the same internal state.static voidcopy(Product source, Product dest)Copies source to dest.doubleevaluate(double[] values, double[] weights)Returns the weighted product of the entries in the input array.doubleevaluate(double[] values, double[] weights, int begin, int length)Returns the weighted product of the entries in the specified portion of the input array, orDouble.NaNif the designated subarray is empty.doubleevaluate(double[] values, int begin, int length)Returns the product of the entries in the specified portion of the input array, orDouble.NaNif the designated subarray is empty.longgetN()Returns the number of values that have been added.doublegetResult()Returns the current value of the Statistic.voidincrement(double d)Updates the internal state of the statistic to reflect the addition of the new value.-
Methods inherited from class org.apache.commons.math4.legacy.stat.descriptive.AbstractStorelessUnivariateStatistic
equals, evaluate, hashCode, incrementAll, incrementAll
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Constructor Detail
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Product
public Product()
Create a Product instance.
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Product
public Product(Product original) throws NullArgumentException
Copy constructor, creates a newProductidentical to theoriginal.- Parameters:
original- theProductinstance to copy- Throws:
NullArgumentException- if original is null
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Method Detail
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increment
public void increment(double d)
Updates the internal state of the statistic to reflect the addition of the new value.- Specified by:
incrementin interfaceStorelessUnivariateStatistic- Specified by:
incrementin classAbstractStorelessUnivariateStatistic- Parameters:
d- the new value.
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getResult
public double getResult()
Returns the current value of the Statistic.- Specified by:
getResultin interfaceStorelessUnivariateStatistic- Specified by:
getResultin classAbstractStorelessUnivariateStatistic- Returns:
- value of the statistic,
Double.NaNif it has been cleared or just instantiated.
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getN
public long getN()
Returns the number of values that have been added.- Specified by:
getNin interfaceStorelessUnivariateStatistic- Returns:
- the number of values.
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clear
public void clear()
Clears the internal state of the Statistic.- Specified by:
clearin interfaceStorelessUnivariateStatistic- Specified by:
clearin classAbstractStorelessUnivariateStatistic
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evaluate
public double evaluate(double[] values, int begin, int length) throws MathIllegalArgumentException
Returns the product of the entries in the specified portion of the input array, orDouble.NaNif the designated subarray is empty.Throws
MathIllegalArgumentExceptionif the array is null.- Specified by:
evaluatein interfaceMathArrays.Function- Specified by:
evaluatein interfaceUnivariateStatistic- Overrides:
evaluatein classAbstractStorelessUnivariateStatistic- Parameters:
values- the input arraybegin- index of the first array element to includelength- the number of elements to include- Returns:
- the product of the values or 1 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)
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evaluate
public double evaluate(double[] values, double[] weights, int begin, int length) throws MathIllegalArgumentException
Returns the weighted product of the entries in the specified portion of the input array, or
Double.NaNif the designated subarray is empty.Throws
MathIllegalArgumentExceptionif 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,
that is, the weights are applied as exponents when computing the weighted product.weighted product = ∏values[i]weights[i]- Specified by:
evaluatein interfaceWeightedEvaluation- Parameters:
values- the input arrayweights- the weights arraybegin- index of the first array element to includelength- the number of elements to include- Returns:
- the product of the values or 1 if length = 0
- Throws:
MathIllegalArgumentException- if the parameters are not valid- Since:
- 2.1
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evaluate
public double evaluate(double[] values, double[] weights) throws MathIllegalArgumentException
Returns the weighted product of the entries in the input array.
Throws
MathIllegalArgumentExceptionif 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,
that is, the weights are applied as exponents when computing the weighted product.weighted product = ∏values[i]weights[i]- Specified by:
evaluatein interfaceWeightedEvaluation- Parameters:
values- the input arrayweights- the weights array- Returns:
- the product of the values or Double.NaN if length = 0
- Throws:
MathIllegalArgumentException- if the parameters are not valid- Since:
- 2.1
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copy
public Product copy()
Returns a copy of the statistic with the same internal state.- Specified by:
copyin interfaceStorelessUnivariateStatistic- Specified by:
copyin interfaceUnivariateStatistic- Specified by:
copyin classAbstractStorelessUnivariateStatistic- Returns:
- a copy of the statistic
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copy
public static void copy(Product source, Product dest) throws NullArgumentException
Copies source to dest.Neither source nor dest can be null.
- Parameters:
source- Product to copydest- Product to copy to- Throws:
NullArgumentException- if either source or dest is null
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