Class SolarIntegrator

java.lang.Object
  Integrator
      RK4
          SolarIntegrator

All Implemented Interfaces:

java.lang.Runnable

public class SolarIntegrator

extends RK4

SolarIntegrator is a subclass of the abstract RK4 class. It implements a function method which represents the mathematical representation of my simplified solar system. (about 90 coupled differential equations :)

Field Summary

Fields inherited from class Integrator

steps, x, x0, x1, y, y0

Constructor Summary

SolarIntegrator(SpaceObject[] o, double t0, double t1, PointN startPoint, int steps)
Constructs a SolarIntegrator for performing numerical integration.

Method Summary

Point	function(double time, Point n) represents the mathematical behaviour of my simplified solar system.
double	getDistance(SpaceObject s, double x, double y, double z) calculates the distance of a SpaceObject s from a certain position in 3D.
Point	integrate() Method for numerical integration.
java.lang.String	toString() This method is NOT USED!!!

Methods inherited from class Integrator

getIV, getLocation, run, setEnd, setSteps

Methods inherited from class java.lang.Object

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

Constructor Detail

SolarIntegrator

public SolarIntegrator(SpaceObject[] o,
                       double t0,
                       double t1,
                       PointN startPoint,
                       int steps)

Constructs a SolarIntegrator for performing numerical integration.

Parameters:

o - arry of SpaceObjects in the system.

t0 - start time of integration (in seconds as I only use SI units).

t1 - stop time of integration.

startPoint - has to be a huge list where the first three entries are the sun coordinates, the next three the sun velocities, and then it is repeating this patter with all planets, following the order: sun -> outwards until Neptun.

steps - number of integration steps between start and stop time

Method Detail

integrate

public Point integrate()

Method for numerical integration.

Overrides:

integrate in class RK4

Returns:

a Point object which contains the new (after the integration) position and velocities of all space objects. Starting with the sun's positions and velocities, then mercury's and so on until neptuns positions and velocities.

function

public Point function(double time,
                      Point n)

represents the mathematical behaviour of my simplified solar system. ~about 90 coupled differential equations, but which is actually just calculating the new velocities and accelerations of each SpaceObject. (i.e. differentiating with respect to time)

Specified by:

function in class Integrator

Parameters:

time - a time step.

n - a Point object holding current positions and velocities.

Returns:

a Point object which contains the velocieties and accelerations of all space objects. Starting with the sun's velocities and accelerations, then mercury's and so on until neptun's.

getDistance

public double getDistance(SpaceObject s,
                          double x,
                          double y,
                          double z)

calculates the distance of a SpaceObject s from a certain position in 3D.

Parameters:

s - a SpaceObject.

x - cartesian x coordinate of a point in 3D.

y - cartesian y coordinate of a point in 3D.

z - cartesian z coordinate of a point in 3D.

Returns:

the distace beetween the SpaceObject s and the point in 3D.

toString

public java.lang.String toString()

This method is NOT USED!!! only implementet because the abstract super class RK4 has it and there fore it is necessary to implement it -> otherwise compiler error!.

Specified by:

toString in class Integrator

Returns:

a empty String.