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 *      http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.math3.ode.sampling;

import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.ode.FieldODEStateAndDerivative;

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 FieldStepNormalizer that itself is used as the general FieldStepHandler by the integrator. The FieldStepNormalizer object is called according to the integrator internal algorithms and it calls objects implementing this interface as necessary at fixed time steps.
Type parameters:
<T> – the type of the field elements
See Also:
FieldStepHandler
FieldStepNormalizer
FieldStepInterpolator
Since:
3.6/**
 * This interface represents a handler that should be called after
 * each successful fixed step.

 * <p>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 FieldStepNormalizer} that itself
 * is used as the general {@link FieldStepHandler} by the integrator. The
 * {@link FieldStepNormalizer} object is called according to the integrator
 * internal algorithms and it calls objects implementing this
 * interface as necessary at fixed time steps.</p>
 *
 * @see FieldStepHandler
 * @see FieldStepNormalizer
 * @see FieldStepInterpolator
 * @param <T> the type of the field elements
 * @since 3.6
 */

public interface FieldFixedStepHandler<T extends RealFieldElement<T>> {

    
Initialize step handler at the start of an ODE integration.

This method is called once at the start of the integration. It
may be used by the step handler to initialize some internal data
if needed.

Params:
initialState – initial time, state vector and derivative
finalTime – target time for the integration/** Initialize step handler at the start of an ODE integration.
     * <p>
     * This method is called once at the start of the integration. It
     * may be used by the step handler to initialize some internal data
     * if needed.
     * </p>
     * @param initialState initial time, state vector and derivative
     * @param finalTime target time for the integration
     */
    void init(FieldODEStateAndDerivative<T> initialState, T finalTime);

    
Handle the last accepted step
Params:
state – current value of the independent time variable, state vector and derivative For efficiency purposes, the FieldStepNormalizer class reuses 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.
isLast – true if the step is the last one/**
     * Handle the last accepted step
     * @param state current value of the independent <i>time</i> variable,
     * state vector and derivative
     * For efficiency purposes, the {@link FieldStepNormalizer} class reuses
     * 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
     */
    void handleStep(FieldODEStateAndDerivative<T> state, boolean isLast);

}