home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (TestFieldProblemAbstract.java)

This example Java source code file (TestFieldProblemAbstract.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

field, fieldeventhandler, fieldodestate, firstorderfielddifferentialequations, realfieldelement, reflection, suppresswarnings, testfieldproblemabstract

The TestFieldProblemAbstract.java Java example source code

/*
 * 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 java.lang.reflect.Array;

import org.apache.commons.math3.Field;
import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.ode.events.FieldEventHandler;
import org.apache.commons.math3.util.MathArrays;

/**
 * This class is used as the base class of the problems that are
 * integrated during the junit tests for the ODE integrators.
 * @param <T> the type of the field elements
 */
public abstract class TestFieldProblemAbstract<T extends RealFieldElement
    implements FirstOrderFieldDifferentialEquations<T> {

    /** Field to which elements belong. */
    private Field<T> field;

    /** Dimension of the problem. */
    private int n;

    /** Number of functions calls. */
    private int calls;

    /** Initial time */
    private T t0;

    /** Initial state */
    private T[] y0;

    /** Final time */
    private T t1;

    /** Error scale */
    private T[] errorScale;

    /**
     * Simple constructor.
     * @param field field to which elements belong
     */
    protected TestFieldProblemAbstract(Field<T> field) {
        this.field = field;
        n          = 0;
        calls      = 0;
        t0         = field.getZero();
        y0         = null;
        t1         = field.getZero();
        errorScale = null;
    }

    /**
     * Set the initial conditions
     * @param t0 initial time
     * @param y0 initial state vector
     */
    protected void setInitialConditions(T t0, T[] y0) {
        calls     = 0;
        n         = y0.length;
        this.t0   = t0;
        this.y0   = y0.clone();
    }

    /**
     * Set the final conditions.
     * @param t1 final time
     */
    protected void setFinalConditions(T t1) {
        this.t1 = t1;
    }

    /**
     * Set the error scale
     * @param errorScale error scale
     */
    protected void setErrorScale(T[] errorScale) {
        this.errorScale = errorScale.clone();
    }

    /** get the filed to which elements belong.
     * @return field to which elements belong
     */
    public Field<T> getField() {
        return field;
    }

    /** Get the problem dimension.
     * @return problem dimension
     */
    public int getDimension() {
        return n;
    }

   /**
     * Get the initial state.
     * @return initial state
     */
    public FieldODEState<T> getInitialState() {
        return new FieldODEState<T>(t0, y0);
    }

    /**
     * Get the final time.
     * @return final time
     */
    public T getFinalTime() {
        return t1;
    }

    /**
     * Get the error scale.
     * @return error scale
     */
    public T[] getErrorScale() {
        return errorScale;
    }

    /**
     * Get the events handlers.
     * @return events handlers   */
    public FieldEventHandler<T>[] getEventsHandlers() {
        @SuppressWarnings("unchecked")
        final FieldEventHandler<T>[] empty =
                        (FieldEventHandler<T>[]) Array.newInstance(FieldEventHandler.class, 0);
        return empty;
    }

    /**
     * Get the theoretical events times.
     * @return theoretical events times
     */
    public T[] getTheoreticalEventsTimes() {
        return MathArrays.buildArray(field, 0);
    }

    /**
     * Get the number of calls.
     * @return nuber of calls
     */
    public int getCalls() {
        return calls;
    }

    /** {@inheritDoc} */
    public void init(T t0, T[] y0, T t) {
    }

    /** {@inheritDoc} */
    public T[] computeDerivatives(T t, T[] y) {
        ++calls;
        return doComputeDerivatives(t, y);
    }

    abstract public T[] doComputeDerivatives(T t, T[] y);

    /**
     * Compute the theoretical state at the specified time.
     * @param t time at which the state is required
     * @return state vector at time t
     */
    abstract public T[] computeTheoreticalState(T t);

    /** Convert a double.
     * @param d double to convert
     * @return converted double
     */
    protected T convert(double d) {
        return field.getZero().add(d);
    }

    /** Convert a one dimension array.
     * @param elements array elements
     * @return converted array
     */
    protected T[] convert(double ... elements) {
        T[] array = MathArrays.buildArray(field, elements.length);
        for (int i = 0; i < elements.length; ++i) {
            array[i] = convert(elements[i]);
        }
        return array;
    }

}

Other Java examples (source code examples)

Here is a short list of links related to this Java TestFieldProblemAbstract.java source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.