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

Java example source code file (Transformer.java)

This example Java source code file (Transformer.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

max, min, minus, override, plus, transformer, uninitialized

The Transformer.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.events;

import org.apache.commons.math3.util.FastMath;
import org.apache.commons.math3.util.Precision;


/** Transformer for {@link EventHandler#g(double, double[]) g functions}.
 * @see EventFilter
 * @see FilterType
 * @since 3.2
 */
enum Transformer {

    /** Transformer computing transformed = 0.
     * <p>
     * This transformer is used when we initialize the filter, until we get at
     * least one non-zero value to select the proper transformer.
     * </p>
     */
    UNINITIALIZED {
        /**  {@inheritDoc} */
        @Override
        protected double transformed(final double g) {
            return 0;
        }
    },

    /** Transformer computing transformed = g.
     * <p>
     * When this transformer is applied, the roots of the original function
     * are preserved, with the same {@code increasing/decreasing} status.
     * </p>
     */
    PLUS {
        /**  {@inheritDoc} */
        @Override
        protected double transformed(final double g) {
            return g;
        }
    },

    /** Transformer computing transformed = -g.
     * <p>
     * When this transformer is applied, the roots of the original function
     * are preserved, with reversed {@code increasing/decreasing} status.
     * </p>
     */
    MINUS {
        /**  {@inheritDoc} */
        @Override
        protected double transformed(final double g) {
            return -g;
        }
    },

    /** Transformer computing transformed = min(-{@link Precision#SAFE_MIN}, -g, +g).
     * <p>
     * When this transformer is applied, the transformed function is
     * guaranteed to be always strictly negative (i.e. there are no roots).
     * </p>
     */
    MIN {
        /**  {@inheritDoc} */
        @Override
        protected double transformed(final double g) {
            return FastMath.min(-Precision.SAFE_MIN, FastMath.min(-g, +g));
        }
    },

    /** Transformer computing transformed = max(+{@link Precision#SAFE_MIN}, -g, +g).
     * <p>
     * When this transformer is applied, the transformed function is
     * guaranteed to be always strictly positive (i.e. there are no roots).
     * </p>
     */
    MAX {
        /**  {@inheritDoc} */
        @Override
        protected double transformed(final double g) {
            return FastMath.max(+Precision.SAFE_MIN, FastMath.max(-g, +g));
        }
    };

    /** Transform value of function g.
     * @param g raw value of function g
     * @return transformed value of function g
     */
    protected abstract double transformed(double g);

}

Other Java examples (source code examples)

Here is a short list of links related to this Java Transformer.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.