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

Class Sum

    • Constructor Summary

      Constructors 
      Constructor and Description
      Sum()
      Create a Sum instance
      Sum(Sum original)
      Copy constructor, creates a new Sum identical to the original
    • Method Summary

      Methods 
      Modifier and TypeMethod and Description
      voidclear()
      Clears the internal state of the Statistic
      Sumcopy()
      Returns a copy of the statistic with the same internal state.
      static voidcopy(Sum source, Sum dest)
      Copies source to dest.
      doubleevaluate(double[] values, double[] weights)
      The weighted sum of the entries in the the input array.
      doubleevaluate(double[] values, double[] 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.
      doubleevaluate(double[] 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.
      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.
    • Constructor Detail

      • Sum

        public Sum()
        Create a Sum instance
    • Method Detail

      • getN

        public long getN()
        Returns the number of values that have been added.
        Specified by:
        getN in interface StorelessUnivariateStatistic
        Returns:
        the number of values.
      • evaluate

        public double evaluate(double[] values,              double[] weights,              int begin,              int length)                throws MathIllegalArgumentException
        The weighted sum of the entries in the specified portion of the input array, or 0 if the designated subarray is empty.

        Throws MathIllegalArgumentException 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:
        MathIllegalArgumentException - if the parameters are not valid
      • evaluate

        public double evaluate(double[] values,              double[] weights)                throws MathIllegalArgumentException
        The weighted sum of the entries in the the input array.

        Throws MathIllegalArgumentException 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:
        MathIllegalArgumentException - if the parameters are not valid
      • copy

        public static void copy(Sum source,        Sum dest)                 throws NullArgumentException
        Copies source to dest.

        Neither source nor dest can be null.

        Parameters:
        source - Sum to copy
        dest - Sum to copy to
        Throws:
        NullArgumentException - if either source or dest is null

SCaVis 2.2 © jWork.ORG