001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.common.math;
017
018import java.math.BigDecimal;
019import java.util.Comparator;
020import java.util.Random;
021import org.modeshape.common.annotation.Immutable;
022
023/**
024 * The {@link MathOperations math operations} for double numbers.
025 */
026@Immutable
027public class DoubleOperations implements MathOperations<Double>, Comparator<Double> {
028
029    @Override
030    public Class<Double> getOperandClass() {
031        return Double.class;
032    }
033
034    @Override
035    public Double add( Double value1,
036                       Double value2 ) {
037        if (value1 == null) return value2 != null ? value2 : createZeroValue();
038        if (value2 == null) return value1;
039        return (value1 + value2);
040    }
041
042    @Override
043    public Double subtract( Double value1,
044                            Double value2 ) {
045        if (value1 == null) return negate(value2);
046        if (value2 == null) return value1;
047        return (value1 - value2);
048    }
049
050    @Override
051    public Double multiply( Double value1,
052                            Double value2 ) {
053        if (value1 == null || value2 == null) return createZeroValue();
054        return (value1 * value2);
055    }
056
057    @Override
058    public double divide( Double value1,
059                          Double value2 ) {
060        if (value1 == null || value2 == null) throw new IllegalArgumentException();
061        return value1 / value2;
062    }
063
064    @Override
065    public Double negate( Double value ) {
066        if (value == null) return createZeroValue();
067        return (value * -1);
068    }
069
070    @Override
071    public Double increment( Double value ) {
072        if (value == null) return createZeroValue();
073        return (value + 1);
074    }
075
076    @Override
077    public Double maximum( Double value1,
078                           Double value2 ) {
079        if (value1 == null) return value2;
080        if (value2 == null) return value1;
081        return Math.max(value1, value2);
082    }
083
084    @Override
085    public Double minimum( Double value1,
086                           Double value2 ) {
087        if (value1 == null) return value2;
088        if (value2 == null) return value1;
089        return Math.min(value1, value2);
090    }
091
092    @Override
093    public int compare( Double value1,
094                        Double value2 ) {
095        if (value1 == null) return value2 != null ? -1 : 0;
096        if (value2 == null) return 1;
097        return value1.compareTo(value2);
098    }
099
100    @Override
101    public BigDecimal asBigDecimal( Double value ) {
102        return value != null ? new BigDecimal(value) : null;
103    }
104
105    @Override
106    public Double fromBigDecimal( BigDecimal value ) {
107        return value != null ? value.doubleValue() : null;
108    }
109
110    @Override
111    public Double createZeroValue() {
112        return 0.0d;
113    }
114
115    @Override
116    public Double create( int value ) {
117        return (double)value;
118    }
119
120    @Override
121    public Double create( long value ) {
122        return (double)value;
123    }
124
125    @Override
126    public Double create( double value ) {
127        return value;
128    }
129
130    @Override
131    public double sqrt( Double value ) {
132        return Math.sqrt(value);
133    }
134
135    @Override
136    public Comparator<Double> getComparator() {
137        return this;
138    }
139
140    @Override
141    public Double random( Double minimum,
142                          Double maximum,
143                          Random rng ) {
144        Double difference = subtract(maximum, minimum);
145        return minimum + difference.doubleValue() * rng.nextDouble();
146    }
147
148    @Override
149    public double doubleValue( Double value ) {
150        return value.doubleValue();
151    }
152
153    @Override
154    public float floatValue( Double value ) {
155        return value.floatValue();
156    }
157
158    @Override
159    public int intValue( Double value ) {
160        return value.intValue();
161    }
162
163    @Override
164    public long longValue( Double value ) {
165        return value.longValue();
166    }
167
168    @Override
169    public short shortValue( Double value ) {
170        return value.shortValue();
171    }
172
173    @Override
174    public int getExponentInScientificNotation( Double value ) {
175        double v = Math.abs(value);
176        int exp = 0;
177        if (v > 1.0d) {
178            while (v >= 10.0d) {
179                v /= 10.0d;
180                ++exp;
181            }
182        } else if (v == 0.0d) {
183        } else if (v < 1.0d) {
184            while (v < 1.0d) {
185                v *= 10.0d;
186                --exp;
187            }
188        }
189        return exp;
190    }
191
192    @Override
193    public Double roundUp( Double value,
194                           int decimalShift ) {
195        if (value == 0) return 0.0d;
196        double shiftedValue = (Math.abs(value) * Math.pow(10.0d, decimalShift) + 0.5d) * Math.signum(value);
197        double roundedValue = (int)shiftedValue;
198        return roundedValue * Math.pow(10.0d, -decimalShift);
199    }
200
201    @Override
202    public Double roundDown( Double value,
203                             int decimalShift ) {
204        if (value == 0) return 0.0d;
205        double shiftedValue = (Math.abs(value) * Math.pow(10.0d, decimalShift)) * Math.signum(value);
206        double roundedValue = (int)shiftedValue;
207        return roundedValue * Math.pow(10.0d, -decimalShift);
208    }
209
210    @Override
211    public Double keepSignificantFigures( Double value,
212                                          int numSigFigs ) {
213        if (numSigFigs < 0) return value;
214        if (numSigFigs == 0) return 0.0d;
215        int currentExp = getExponentInScientificNotation(value);
216        int decimalShift = -currentExp + numSigFigs - 1;
217        return roundUp(value, decimalShift);
218    }
219}