ComplexOrdinaryDifferentialEquation.java

/*
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 * this work for additional information regarding copyright ownership.
 * The Hipparchus project licenses this file to You under the Apache License, Version 2.0
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 *      https://www.apache.org/licenses/LICENSE-2.0
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package org.hipparchus.ode;

import org.hipparchus.complex.Complex;

/** This interface represents a first order differential equations set for {@link Complex complex state}.
 *
 * @see OrdinaryDifferentialEquation
 * @see ComplexODEConverter
 * @since 1.4
 *
 */
public interface ComplexOrdinaryDifferentialEquation {

    /** Get the dimension of the problem.
     * @return dimension of the problem
     */
    int getDimension();

    /** Initialize equations 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 equations to initialize some internal data
     * if needed.
     * </p>
     * <p>
     * The default implementation does nothing.
     * </p>
     * @param t0 value of the independent <I>time</I> variable at integration start
     * @param y0 array containing the value of the state vector at integration start
     * @param finalTime target time for the integration
     */
    default void init(double t0, Complex[] y0, double finalTime) {
        // do nothing by default
    }

    /** Get the current time derivative of the state vector.
     * @param t current value of the independent <I>time</I> variable
     * @param y array containing the current value of the state vector
     * @return time derivative of the state vector
     */
    Complex[] computeDerivatives(double t, Complex[] y);

}