UnivariateDerivative1Field.java
/*
* Licensed to the Hipparchus project under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The Hipparchus project 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
*
* https://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.hipparchus.analysis.differentiation;
import java.io.Serializable;
import org.hipparchus.Field;
/** Field for {@link UnivariateDerivative1} instances.
* <p>
* This class is a singleton.
* </p>
* @since 1.7
*/
public class UnivariateDerivative1Field implements Field<UnivariateDerivative1>, Serializable {
/** Serializable version identifier. */
private static final long serialVersionUID = 20200519L;
/** Zero constant. */
private final UnivariateDerivative1 zero;
/** One constant. */
private final UnivariateDerivative1 one;
/** Associated factory for conversions to {@link DerivativeStructure}. */
private final DSFactory factory;
/** Private constructor for the singleton.
*/
private UnivariateDerivative1Field() {
zero = new UnivariateDerivative1(0.0, 0.0);
one = new UnivariateDerivative1(1.0, 0.0);
factory = new DSFactory(1, 1);
}
/** Get the unique instance.
* @return the unique instance
*/
public static UnivariateDerivative1Field getInstance() {
return LazyHolder.INSTANCE;
}
/** {@inheritDoc} */
@Override
public UnivariateDerivative1 getOne() {
return one;
}
/** {@inheritDoc} */
@Override
public UnivariateDerivative1 getZero() {
return zero;
}
/** Get the factory for converting to {@link DerivativeStructure}.
* <p>
* This factory is used only for conversions. {@code UnivariateDerivative1} by
* itself does not rely at all on {@link DSFactory}, {@link DSCompiler}
* or {@link DerivativeStructure} for its computation. For this reason,
* the factory here is hidden and this method is package private, so
* only {@link UnivariateDerivative1#toDerivativeStructure()} can call it on an
* existing {@link UnivariateDerivative1} instance
* </p>
* @return factory for conversions
*/
DSFactory getConversionFactory() {
return factory;
}
/** {@inheritDoc} */
@Override
public Class<UnivariateDerivative1> getRuntimeClass() {
return UnivariateDerivative1.class;
}
/** {@inheritDoc} */
@Override
public boolean equals(final Object other) {
return this == other;
}
/** {@inheritDoc} */
@Override
public int hashCode() {
return 0xd5e174f7;
}
// CHECKSTYLE: stop HideUtilityClassConstructor
/** Holder for the instance.
* <p>We use here the Initialization On Demand Holder Idiom.</p>
*/
private static class LazyHolder {
/** Cached field instance. */
private static final UnivariateDerivative1Field INSTANCE = new UnivariateDerivative1Field();
}
// CHECKSTYLE: resume HideUtilityClassConstructor
/** Handle deserialization of the singleton.
* @return the singleton instance
*/
private Object readResolve() {
// return the singleton instance
return LazyHolder.INSTANCE;
}
}