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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;
import org.apache.commons.math3.Field;
import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.util.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)}.
*
* @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();
}
}
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