Package nl.tudelft.simulation.jstats.ode

Class DifferentialEquation

java.lang.Object
org.djutils.event.LocalEventProducer
nl.tudelft.simulation.jstats.ode.DifferentialEquation
All Implemented Interfaces:
Serializable, Remote, DifferentialEquationInterface, org.djutils.event.EventProducer
Direct Known Subclasses:
DifferentialEquation
public abstract class DifferentialEquation extends org.djutils.event.LocalEventProducer implements DifferentialEquationInterface
The DifferentialEquation is the abstract basis for the DESS formalism.

Copyright (c) 2002-2024 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://simulation.tudelft.nl. The DSOL project is distributed under a three-clause BSD-style license, which can be found at https://https://simulation.tudelft.nl/dsol/docs/latest/license.html.

Author:
Alexander Verbraeck, Peter Jacobs
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected double
    lastX
    the last x value, initialized with x0 to start integration.
    protected double[]
    lastY
    the last calculated value array for lastX, initialized with the initial value array y0.
    protected double
    stepSize
    the stepSize; can be negative or positive.

    Fields inherited from interface org.djutils.event.EventProducer

    FIRST_POSITION, LAST_POSITION

  • Constructor Summary

    Constructors
    Constructor
    Description
    DifferentialEquation(double stepSize, NumericalIntegratorType integratorType)
    constructs a new DifferentialEquation with a user-specified integrator.

  • Method Summary

    Modifier and Type
    Method
    Description
    NumericalIntegrator
    getIntegrator()
     
    void
    initialize(double x0, double[] y0)
    initializes the differential equation.
    protected double[]
    integrateY(double x, double initialX, double[] initialY)
    integrates Y.
    void
    setIntegrator(NumericalIntegrator integrator)
     
    double[]
    y(double x)
    returns y as a function of x.

    Methods inherited from class org.djutils.event.LocalEventProducer

    addListener, addListener, addListener, addListener, fireEvent, fireEvent, fireEvent, fireTimedEvent, fireTimedEvent, fireTimedEvent, fireUnverifiedEvent, fireUnverifiedEvent, fireUnverifiedTimedEvent, fireUnverifiedTimedEvent, getEventListenerMap, getEventTypesWithListeners, getListenerReferences, hasListeners, numberOfListeners, removeAllListeners, removeAllListeners, removeListener

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface nl.tudelft.simulation.jstats.ode.DifferentialEquationInterface

    dy

  • Field Details

    • lastY

      protected double[] lastY
      the last calculated value array for lastX, initialized with the initial value array y0.

    • stepSize

      protected double stepSize
      the stepSize; can be negative or positive.

    • lastX

      protected double lastX
      the last x value, initialized with x0 to start integration.

  • Constructor Details

    • DifferentialEquation

      public DifferentialEquation(double stepSize, NumericalIntegratorType integratorType)
      constructs a new DifferentialEquation with a user-specified integrator.
      Parameters:
      stepSize - double; the stepSize to use.
      integratorType - NumericalIntegratorType; the integrator to use.

  • Method Details

    • initialize

      public void initialize(double x0, double[] y0)
      initializes the differential equation.
      Specified by:
      initialize in interface DifferentialEquationInterface
      Parameters:
      x0 - double; the initial x-value
      y0 - double[]; the initial y-value array

    • y

      public double[] y(double x)
      returns y as a function of x.
      Specified by:
      y in interface DifferentialEquationInterface
      Parameters:
      x - double; the x-value
      Returns:
      y

    • integrateY

      protected double[] integrateY(double x, double initialX, double[] initialY)
      integrates Y.
      Parameters:
      x - double; the x-value
      initialX - double; the initial X value, non-final (will be updated)
      initialY - double[]; the initial Y value, non-final (will be updated)
      Returns:
      the new Y value

    • getIntegrator

      public NumericalIntegrator getIntegrator()
      Returns:
      Returns the integrator.

    • setIntegrator

      public void setIntegrator(NumericalIntegrator integrator)
      Parameters:
      integrator - NumericalIntegrator; The integrator to set.