home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (MidpointFieldIntegrator.java)

This example Java source code file (MidpointFieldIntegrator.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

fieldequationsmapper, fieldodestateandderivative, midpointfieldintegrator, midpointfieldstepinterpolator, override, realfieldelement, rungekuttafieldintegrator

The MidpointFieldIntegrator.java Java example source code

 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.commons.math3.ode.nonstiff;

import org.apache.commons.math3.Field;
import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.ode.FieldEquationsMapper;
import org.apache.commons.math3.ode.FieldODEStateAndDerivative;
import org.apache.commons.math3.util.MathArrays;

 * This class implements a second order Runge-Kutta integrator for
 * Ordinary Differential Equations.
 * <p>This method is an explicit Runge-Kutta method, its Butcher-array
 * is the following one :
 * <pre>
 *    0  |  0    0
 *   1/2 | 1/2   0
 *       |----------
 *       |  0    1
 * </pre>
 * </p>
 * @see EulerFieldIntegrator
 * @see ClassicalRungeKuttaFieldIntegrator
 * @see GillFieldIntegrator
 * @see ThreeEighthesFieldIntegrator
 * @see LutherFieldIntegrator
 * @param <T> the type of the field elements
 * @since 3.6

public class MidpointFieldIntegrator<T extends RealFieldElement extends RungeKuttaFieldIntegrator {

    /** Simple constructor.
     * Build a midpoint integrator with the given step.
     * @param field field to which the time and state vector elements belong
     * @param step integration step
    public MidpointFieldIntegrator(final Field<T> field, final T step) {
        super(field, "midpoint", step);

    /** {@inheritDoc} */
    public T[] getC() {
        final T[] c = MathArrays.buildArray(getField(), 1);
        c[0] = getField().getOne().multiply(0.5);
        return c;

    /** {@inheritDoc} */
    public T[][] getA() {
        final T[][] a = MathArrays.buildArray(getField(), 1, 1);
        a[0][0] = fraction(1, 2);
        return a;

    /** {@inheritDoc} */
    public T[] getB() {
        final T[] b = MathArrays.buildArray(getField(), 2);
        b[0] = getField().getZero();
        b[1] = getField().getOne();
        return b;

    /** {@inheritDoc} */
    protected MidpointFieldStepInterpolator<T>
        createInterpolator(final boolean forward, T[][] yDotK,
                           final FieldODEStateAndDerivative<T> globalPreviousState,
                           final FieldODEStateAndDerivative<T> globalCurrentState,
                           final FieldEquationsMapper<T> mapper) {
        return new MidpointFieldStepInterpolator<T>(getField(), forward, yDotK,
                                                    globalPreviousState, globalCurrentState,
                                                    globalPreviousState, globalCurrentState,


Other Java examples (source code examples)

Here is a short list of links related to this Java MidpointFieldIntegrator.java source code file:

my book on functional programming


new blog posts


Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.