// File: Averager.java from the package edu.colorado.simulations
// Additional javadoc documentation is available from the Averager link at
// http://www.cs.colorado.edu/~main/docs/
/******************************************************************************
* An Averager computes an average of a group of numbers.
*
* Java Source Code for this class:
*
* http://www.cs.colorado.edu/~main/edu/colorado/simulations/Averager.java
*
*
* @author Michael Main
* (main@colorado.edu)
*
* @version
* Jun 12, 1998
******************************************************************************/
public class Averager
{
private int count; // How many numbers have been given to this averager
private double sum; // Sum of all the numbers given to this averager
/**
* Initialize an Averager.
* param - none
* Postcondition:
* This Averager has been initialized and is ready to accept numbers.
**/
public Averager( )
{
count =0;
sum = 0;
}
/**
* Give another number to this Averager.
* @param value
* the next number to give to this Averager
* Precondition:
* howManyNumbers() < Integer.MAX_VALUE.
* Postcondition:
* This Averager has accepted value as the next number.
* @exception IllegalStateException
* Indicates that howManyNumbers() is
* Integer.MAX_VALUE.
**/
public void addNumber(double value)
{
if (count == Integer.MAX_VALUE)
throw new IllegalStateException("Too many numbers");
count++;
sum += value;
}
/**
* Provide an average of all numbers given to this Averager.
* @param - none
* @return
* the average of all the numbers that have been given to this
* Averager
* the next number to give to this Averager
* Postcondition:
* If howManyNumbers() is zero, then the answer is
* Double.NaN ("not a number"). The answer may also be
* Double.POSITIVE_INFINITY or
* Double.NEGATIVE_INFINITY if there has been an arithmetic
* overflow during the summing of all the numbers.
**/
public double average( )
{
if (count == 0)
return Double.NaN;
else
return sum/count;
}
/**
* Provide a count of how many numbers have been given to this Averager.
* @param - none
* @return
* the count of how many numbers have been given to this Averager
**/
public int howManyNumbers( )
{
return count;
}
}