1 /*
2 * Licensed to the Hipparchus project under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The Hipparchus project licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.hipparchus.analysis.differentiation;
18
19 import java.util.HashMap;
20 import java.util.Map;
21
22 import org.hipparchus.CalculusFieldElement;
23 import org.hipparchus.Field;
24
25 /** Field for {@link FieldUnivariateDerivative2} instances.
26 * @param <T> the type of the function parameters and value
27 * @since 1.7
28 */
29 public class FieldUnivariateDerivative2Field<T extends CalculusFieldElement<T>> implements Field<FieldUnivariateDerivative2<T>> {
30
31 /** Cached fields. */
32 private static final Map<Field<?>, FieldUnivariateDerivative2Field<?>> CACHE = new HashMap<>();
33
34 /** Zero constant. */
35 private final FieldUnivariateDerivative2<T> zero;
36
37 /** One constant. */
38 private final FieldUnivariateDerivative2<T> one;
39
40 /** Associated factory for conversions to {@link FieldDerivativeStructure}. */
41 private final FDSFactory<T> factory;
42
43 /** Private constructor for populating the cache.
44 * @param valueField field for the function parameters and value
45 */
46 private FieldUnivariateDerivative2Field(final Field<T> valueField) {
47 zero = new FieldUnivariateDerivative2<>(valueField.getZero(), valueField.getZero(), valueField.getZero());
48 one = new FieldUnivariateDerivative2<>(valueField.getOne(), valueField.getZero(), valueField.getZero());
49 factory = new FDSFactory<>(valueField, 1, 2);
50 }
51
52 /** Get the univariate derivative field corresponding to a value field.
53 * @param valueField field for the function parameters and value
54 * @param <T> the type of the function parameters and value
55 * @return univariate derivative field
56 */
57 public static <T extends CalculusFieldElement<T>> FieldUnivariateDerivative2Field<T> getUnivariateDerivative2Field(final Field<T> valueField) {
58 synchronized (CACHE) {
59 FieldUnivariateDerivative2Field<?> cached = CACHE.get(valueField);
60 if (cached == null) {
61 cached = new FieldUnivariateDerivative2Field<>(valueField);
62 CACHE.put(valueField, cached);
63 }
64 @SuppressWarnings("unchecked")
65 final FieldUnivariateDerivative2Field<T> tCached = (FieldUnivariateDerivative2Field<T>) cached;
66 return tCached;
67 }
68 }
69
70 /** {@inheritDoc} */
71 @Override
72 public FieldUnivariateDerivative2<T> getOne() {
73 return one;
74 }
75
76 /** {@inheritDoc} */
77 @Override
78 public FieldUnivariateDerivative2<T> getZero() {
79 return zero;
80 }
81
82 /** Get the factory for converting to {@link DerivativeStructure}.
83 * <p>
84 * This factory is used only for conversions. {@code UnivariateDerivative2} by
85 * itself does not rely at all on {@link DSFactory}, {@link DSCompiler}
86 * or {@link DerivativeStructure} for its computation. For this reason,
87 * the factory here is hidden and this method is package private, so
88 * only {@link UnivariateDerivative2#toDerivativeStructure()} can call it on an
89 * existing {@link UnivariateDerivative2} instance
90 * </p>
91 * @return factory for conversions
92 */
93 FDSFactory<T> getConversionFactory() {
94 return factory;
95 }
96
97 /** {@inheritDoc} */
98 @SuppressWarnings("unchecked")
99 @Override
100 public Class<FieldUnivariateDerivative2<T>> getRuntimeClass() {
101 return (Class<FieldUnivariateDerivative2<T>>) zero.getClass();
102 }
103
104 /** {@inheritDoc} */
105 @Override
106 public boolean equals(final Object other) {
107 return this == other;
108 }
109
110 /** {@inheritDoc} */
111 @Override
112 public int hashCode() {
113 return 0x3f4b793e;
114 }
115
116 }