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


This class implements a second order Runge-Kutta integrator for
Ordinary Differential Equations.
This method is an explicit Runge-Kutta method, its Butcher-array
is the following one :
   0  |  0    0
  1/2 | 1/2   0
      |----------
      |  0    1


See Also:
EulerIntegrator
ClassicalRungeKuttaIntegrator
GillIntegrator
ThreeEighthesIntegrator
LutherIntegrator
Since:
1.2/**
 * 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 EulerIntegrator
 * @see ClassicalRungeKuttaIntegrator
 * @see GillIntegrator
 * @see ThreeEighthesIntegrator
 * @see LutherIntegrator
 *
 * @since 1.2
 */

public class MidpointIntegrator extends RungeKuttaIntegrator {

  
Time steps Butcher array. /** Time steps Butcher array. */
  private static final double[] STATIC_C = {
    1.0 / 2.0
  };

  
Internal weights Butcher array. /** Internal weights Butcher array. */
  private static final double[][] STATIC_A = {
    { 1.0 / 2.0 }
  };

  
Propagation weights Butcher array. /** Propagation weights Butcher array. */
  private static final double[] STATIC_B = {
    0.0, 1.0
  };

  
Simple constructor.
Build a midpoint integrator with the given step.
Params:
step – integration step/** Simple constructor.
   * Build a midpoint integrator with the given step.
   * @param step integration step
   */
  public MidpointIntegrator(final double step) {
    super("midpoint", STATIC_C, STATIC_A, STATIC_B, new MidpointStepInterpolator(), step);
  }

}