org.apache.commons.math3.ode.nonstiff.ClassicalRungeKuttaIntegrator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of commons-math3 Show documentation
Show all versions of commons-math3 Show documentation
The Apache Commons Math project is a library of lightweight, self-contained mathematics and statistics components addressing the most common practical problems not immediately available in the Java programming language or commons-lang.
/*
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math3.ode.nonstiff;
/**
* This class implements the classical fourth order Runge-Kutta
* integrator for Ordinary Differential Equations (it is the most
* often used Runge-Kutta method).
*
* This method is an explicit Runge-Kutta method, its Butcher-array
* is the following one :
*
* 0 | 0 0 0 0
* 1/2 | 1/2 0 0 0
* 1/2 | 0 1/2 0 0
* 1 | 0 0 1 0
* |--------------------
* | 1/6 1/3 1/3 1/6
*
*
*
* @see EulerIntegrator
* @see GillIntegrator
* @see MidpointIntegrator
* @see ThreeEighthesIntegrator
* @see LutherIntegrator
* @since 1.2
*/
public class ClassicalRungeKuttaIntegrator extends RungeKuttaIntegrator {
/** Time steps Butcher array. */
private static final double[] STATIC_C = {
1.0 / 2.0, 1.0 / 2.0, 1.0
};
/** Internal weights Butcher array. */
private static final double[][] STATIC_A = {
{ 1.0 / 2.0 },
{ 0.0, 1.0 / 2.0 },
{ 0.0, 0.0, 1.0 }
};
/** Propagation weights Butcher array. */
private static final double[] STATIC_B = {
1.0 / 6.0, 1.0 / 3.0, 1.0 / 3.0, 1.0 / 6.0
};
/** Simple constructor.
* Build a fourth-order Runge-Kutta integrator with the given
* step.
* @param step integration step
*/
public ClassicalRungeKuttaIntegrator(final double step) {
super("classical Runge-Kutta", STATIC_C, STATIC_A, STATIC_B,
new ClassicalRungeKuttaStepInterpolator(), step);
}
}