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/*
* 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;
import org.apache.commons.math3.Field;
import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.MaxCountExceededException;
import org.apache.commons.math3.exception.NoBracketingException;
import org.apache.commons.math3.exception.NumberIsTooSmallException;
import org.apache.commons.math3.linear.Array2DRowFieldMatrix;
import org.apache.commons.math3.ode.FieldExpandableODE;
import org.apache.commons.math3.ode.FieldODEState;
import org.apache.commons.math3.ode.FieldODEStateAndDerivative;
import org.apache.commons.math3.ode.MultistepFieldIntegrator;
/** Base class for {@link AdamsBashforthFieldIntegrator Adams-Bashforth} and
* {@link AdamsMoultonFieldIntegrator Adams-Moulton} integrators.
* @param <T> the type of the field elements
* @since 3.6
*/
public abstract class AdamsFieldIntegrator<T extends RealFieldElement<T>> extends MultistepFieldIntegrator<T> {
/** Transformer. */
private final AdamsNordsieckFieldTransformer<T> transformer;
/**
* Build an Adams integrator with the given order and step control parameters.
* @param field field to which the time and state vector elements belong
* @param name name of the method
* @param nSteps number of steps of the method excluding the one being computed
* @param order order of the method
* @param minStep minimal step (sign is irrelevant, regardless of
* integration direction, forward or backward), the last step can
* be smaller than this
* @param maxStep maximal step (sign is irrelevant, regardless of
* integration direction, forward or backward), the last step can
* be smaller than this
* @param scalAbsoluteTolerance allowed absolute error
* @param scalRelativeTolerance allowed relative error
* @exception NumberIsTooSmallException if order is 1 or less
*/
public AdamsFieldIntegrator(final Field<T> field, final String name,
final int nSteps, final int order,
final double minStep, final double maxStep,
final double scalAbsoluteTolerance,
final double scalRelativeTolerance)
throws NumberIsTooSmallException {
super(field, name, nSteps, order, minStep, maxStep,
scalAbsoluteTolerance, scalRelativeTolerance);
transformer = AdamsNordsieckFieldTransformer.getInstance(field, nSteps);
}
/**
* Build an Adams integrator with the given order and step control parameters.
* @param field field to which the time and state vector elements belong
* @param name name of the method
* @param nSteps number of steps of the method excluding the one being computed
* @param order order of the method
* @param minStep minimal step (sign is irrelevant, regardless of
* integration direction, forward or backward), the last step can
* be smaller than this
* @param maxStep maximal step (sign is irrelevant, regardless of
* integration direction, forward or backward), the last step can
* be smaller than this
* @param vecAbsoluteTolerance allowed absolute error
* @param vecRelativeTolerance allowed relative error
* @exception IllegalArgumentException if order is 1 or less
*/
public AdamsFieldIntegrator(final Field<T> field, final String name,
final int nSteps, final int order,
final double minStep, final double maxStep,
final double[] vecAbsoluteTolerance,
final double[] vecRelativeTolerance)
throws IllegalArgumentException {
super(field, name, nSteps, order, minStep, maxStep,
vecAbsoluteTolerance, vecRelativeTolerance);
transformer = AdamsNordsieckFieldTransformer.getInstance(field, nSteps);
}
/** {@inheritDoc} */
public abstract FieldODEStateAndDerivative<T> integrate(final FieldExpandableODE<T> equations,
final FieldODEState<T> initialState,
final T finalTime)
throws NumberIsTooSmallException, DimensionMismatchException,
MaxCountExceededException, NoBracketingException;
/** {@inheritDoc} */
@Override
protected Array2DRowFieldMatrix<T> initializeHighOrderDerivatives(final T h, final T[] t,
final T[][] y,
final T[][] yDot) {
return transformer.initializeHighOrderDerivatives(h, t, y, yDot);
}
/** Update the high order scaled derivatives for Adams integrators (phase 1).
* <p>The complete update of high order derivatives has a form similar to:
* <pre>
* r<sub>n+1</sub> = (s<sub>1</sub>(n) - s<sub>1</sub>(n+1)) P<sup>-1</sup> u + P<sup>-1</sup> A P r<sub>n</sub>
* </pre>
* this method computes the P<sup>-1</sup> A P r<sub>n</sub> part.</p>
* @param highOrder high order scaled derivatives
* (h<sup>2</sup>/2 y'', ... h<sup>k</sup>/k! y(k))
* @return updated high order derivatives
* @see #updateHighOrderDerivativesPhase2(RealFieldElement[], RealFieldElement[], Array2DRowFieldMatrix)
*/
public Array2DRowFieldMatrix<T> updateHighOrderDerivativesPhase1(final Array2DRowFieldMatrix<T> highOrder) {
return transformer.updateHighOrderDerivativesPhase1(highOrder);
}
/** Update the high order scaled derivatives Adams integrators (phase 2).
* <p>The complete update of high order derivatives has a form similar to:
* <pre>
* r<sub>n+1</sub> = (s<sub>1</sub>(n) - s<sub>1</sub>(n+1)) P<sup>-1</sup> u + P<sup>-1</sup> A P r<sub>n</sub>
* </pre>
* this method computes the (s<sub>1</sub>(n) - s<sub>1</sub>(n+1)) P<sup>-1</sup> u part.</p>
* <p>Phase 1 of the update must already have been performed.</p>
* @param start first order scaled derivatives at step start
* @param end first order scaled derivatives at step end
* @param highOrder high order scaled derivatives, will be modified
* (h<sup>2</sup>/2 y'', ... h<sup>k</sup>/k! y(k))
* @see #updateHighOrderDerivativesPhase1(Array2DRowFieldMatrix)
*/
public void updateHighOrderDerivativesPhase2(final T[] start, final T[] end,
final Array2DRowFieldMatrix<T> highOrder) {
transformer.updateHighOrderDerivativesPhase2(start, end, highOrder);
}
}
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