package org.spaceroots.mantissa.ode;

/**
 * This interface represents a handler that should be called after
 * each successful fixed step.

 * 
This interface should be implemented by anyone who is interested
 * in getting the solution of an ordinary differential equation at
 * fixed time steps. Objects implementing this interface should be
 * wrapped within an instance of {@link StepNormalizer} that itself
 * is used as the general {@link StepHandler} by the integrator. The
 * {@link StepNormalizer} object is called according to the integrator
 * internal algorithms and it calls objects implementing this
 * interface as necessary at fixed time steps.

 * @see StepHandler
 * @see StepNormalizer

 * @version $Id: FixedStepHandler.java 1419 2002-12-24 20:32:54Z luc $
 * @author L. Maisonobe

 */

public interface FixedStepHandler {

  /**
   * Handle the last accepted step
   * @param t time of the current step

   * @param y state vector at t. For efficiency purposes, the {@link
   * StepNormalizer} class reuse the same array on each call, so if
   * the instance wants to keep it across all calls (for example to
   * provide at the end of the integration a complete array of all
   * steps), it should build a local copy store this copy.

   * @param isLast true if the step is the last one
   */
  public void handleStep(double t, double[] y, boolean isLast);
    
}