net.sf.doodleproject.numerics4j.series
Class PowerSeries

java.lang.Object
  net.sf.doodleproject.numerics4j.IterativeMethod
      net.sf.doodleproject.numerics4j.series.PowerSeries

public abstract class PowerSeries
extends IterativeMethod

This class provides the means to evaluate infinite power series (1). To create a power series, authors subclass this class and provided a concrete term method.

For example, this is the power series for the exponential function defined by (2):

 PowerSeries exponential = new PowerSeries() {
     public double getTerm(int n) {
         return 1.0 / factorial(n);
     }
 
     private double factorial(int n) {
         double p = 1.0;
         while(n > 1.0) {
             p *= n--;
         }
         return p;
     }
 }
 

References:

1. Eric W. Weisstein. "Power Series." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/PowerSeries.html
2. Exponential Function: Series Representation. http://functions.wolfram.com/01.03.06.0002.01

Since:

1.1

Version:

$Revision: 1.2 $ $Date: 2007/10/25 04:44:14 $

Nested Class Summary

Nested classes/interfaces inherited from class net.sf.doodleproject.numerics4j.IterativeMethod

IterativeMethod.IterativeState

Constructor Summary

protected	PowerSeries() Default constructor.
protected	PowerSeries(int iterations, double error) Create a series with the given number of maximum iterations and maximum relative error.
protected	PowerSeries(int index, int iterations, double error) Create a series with the given first term index, number of maximum iterations and maximum relative error.

Method Summary

double	evaluate(double x) Evaluate this series at the given value.
protected abstract double	getTerm(int n) Access the n-th term for this series.

Methods inherited from class net.sf.doodleproject.numerics4j.IterativeMethod

getMaximumIterations, getMaximumRelativeError, iterate, setMaximumIterations, setMaximumRelativeError

Methods inherited from class java.lang.Object

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

Constructor Detail

PowerSeries

protected PowerSeries()

Default constructor.

PowerSeries

protected PowerSeries(int iterations,
                      double error)

Create a series with the given number of maximum iterations and maximum relative error.

Parameters:

iterations - maximum number of iterations.

error - maximum relative error.

PowerSeries

protected PowerSeries(int index,
                      int iterations,
                      double error)

Create a series with the given first term index, number of maximum iterations and maximum relative error.

Parameters:

index - index of first term in this series.

iterations - maximum number of iterations.

error - maximum relative error.

Method Detail

evaluate

public double evaluate(double x)
                throws NumericException

Evaluate this series at the given value.

Parameters:

x - the point of evalutation.

Returns:

the value of this series evaluated at x.

Throws:

NumericException - if the series could not be evaluated.

getTerm

protected abstract double getTerm(int n)

Access the n-th term for this series.

Parameters:

n - the term index.

Returns:

the n-th series term.