FieldODEState.java
- /*
- * 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.math4.legacy.ode;
- import org.apache.commons.math4.legacy.core.Field;
- import org.apache.commons.math4.legacy.core.RealFieldElement;
- import org.apache.commons.math4.legacy.core.MathArrays;
- /** Container for time, main and secondary state vectors.
- * @see FirstOrderFieldDifferentialEquations
- * @see FieldSecondaryEquations
- * @see FirstOrderFieldIntegrator
- * @see FieldODEStateAndDerivative
- * @param <T> the type of the field elements
- * @since 3.6
- */
- public class FieldODEState<T extends RealFieldElement<T>> {
- /** Time. */
- private final T time;
- /** Main state at time. */
- private final T[] state;
- /** Secondary state at time. */
- private final T[][] secondaryState;
- /** Simple constructor.
- * <p>Calling this constructor is equivalent to call {@link
- * #FieldODEState(RealFieldElement, RealFieldElement[], RealFieldElement[][])
- * FieldODEState(time, state, null)}.</p>
- * @param time time
- * @param state state at time
- */
- public FieldODEState(T time, T[] state) {
- this(time, state, null);
- }
- /** Simple constructor.
- * @param time time
- * @param state state at time
- * @param secondaryState state at time (may be null)
- */
- public FieldODEState(T time, T[] state, T[][] secondaryState) {
- this.time = time;
- this.state = state.clone();
- this.secondaryState = copy(time.getField(), secondaryState);
- }
- /** Copy a two-dimensions array.
- * @param field field to which elements belong
- * @param original original array (may be null)
- * @return copied array or null if original array was null
- */
- protected T[][] copy(final Field<T> field, final T[][] original) {
- // special handling of null arrays
- if (original == null) {
- return null;
- }
- // allocate the array
- final T[][] copied = MathArrays.buildArray(field, original.length, -1);
- // copy content
- for (int i = 0; i < original.length; ++i) {
- copied[i] = original[i].clone();
- }
- return copied;
- }
- /** Get time.
- * @return time
- */
- public T getTime() {
- return time;
- }
- /** Get main state dimension.
- * @return main state dimension
- */
- public int getStateDimension() {
- return state.length;
- }
- /** Get main state at time.
- * @return main state at time
- */
- public T[] getState() {
- return state.clone();
- }
- /** Get the number of secondary states.
- * @return number of secondary states.
- */
- public int getNumberOfSecondaryStates() {
- return secondaryState == null ? 0 : secondaryState.length;
- }
- /** Get secondary state dimension.
- * @param index index of the secondary set as returned
- * by {@link FieldExpandableODE#addSecondaryEquations(FieldSecondaryEquations)}
- * (beware index 0 corresponds to main state, additional states start at 1)
- * @return secondary state dimension
- */
- public int getSecondaryStateDimension(final int index) {
- return index == 0 ? state.length : secondaryState[index - 1].length;
- }
- /** Get secondary state at time.
- * @param index index of the secondary set as returned
- * by {@link FieldExpandableODE#addSecondaryEquations(FieldSecondaryEquations)}
- * (beware index 0 corresponds to main state, additional states start at 1)
- * @return secondary state at time
- */
- public T[] getSecondaryState(final int index) {
- return index == 0 ? state.clone() : secondaryState[index - 1].clone();
- }
- }