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8 package org.lsmp.djep.groupJep.values;
9 import java.math.*;
10
17 public class Rational extends Number  implements Comparable {
18
19 private BigInteger numerator;
20 private BigInteger denominator;
21
23 private Rational() { }
24
25 public Rational(BigInteger num) {
26 numerator = num; denominator = BigInteger.ONE;
27 }
28
29
32 public Rational(BigInteger num,BigInteger den) {
33 BigInteger gcd = num.gcd(den);
34 if(gcd.equals(BigInteger.ZERO)) {
35 numerator = denominator = BigInteger.ZERO;
36 }
37 else if(den.signum() > 0){
38 numerator = num.divide(gcd);
39 denominator = den.divide(gcd);
40 }
41 else {
42 numerator = num.divide(gcd).negate();
43 denominator = den.divide(gcd).negate();
44 }
45 }
46
47 public int intValue()
48 {
49 if(denominator.equals(BigInteger.ZERO))
50 {
51 int sign = numerator.signum();
52 if(sign == 0)
53 return Integer.MAX_VALUE;
54 else if(sign > 0 )
55 return Integer.MAX_VALUE;
56 else
57 return Integer.MIN_VALUE;
58 }
59 return numerator.divide(denominator).intValue();
60 }
61 public long longValue()
62 {
63 return numerator.divide(denominator).longValue();
64 }
65 public float floatValue()
66 {
67 if(denominator.equals(BigInteger.ZERO))
68 {
69 int sign = numerator.signum();
70 if(sign == 0)
71 return Float.NaN;
72 else if(sign > 0 )
73 return Float.POSITIVE_INFINITY;
74 else
75 return Float.NEGATIVE_INFINITY;
76 }
77 return numerator.divide(denominator).floatValue();
78 }
79 public double doubleValue()
80 {
81 if(denominator.equals(BigInteger.ZERO))
82 {
83 int sign = numerator.signum();
84 if(sign == 0)
85 return Double.NaN;
86 else if(sign > 0 )
87 return Double.POSITIVE_INFINITY;
88 else
89 return Double.NEGATIVE_INFINITY;
90 }
91 return numerator.divide(denominator).doubleValue();
92 }
93
94 public Rational add(Rational arg)
95 {
96 BigInteger ad = this.numerator.multiply(arg.denominator);
97 BigInteger bc = this.denominator.multiply(arg.numerator);
98 BigInteger bd = this.denominator.multiply(arg.denominator);
99 BigInteger top = ad.add(bc);
100 return new Rational(top,bd);
101 }
102
103 public Rational sub(Rational arg)
104 {
105 BigInteger ad = this.numerator.multiply(arg.denominator);
106 BigInteger bc = this.denominator.multiply(arg.numerator);
107 BigInteger bd = this.denominator.multiply(arg.denominator);
108 BigInteger top = ad.subtract(bc);
109 return new Rational(top,bd);
110 }
111
112 public Rational mul(Rational arg)
113 {
114 BigInteger ac = this.numerator.multiply(arg.numerator);
115 BigInteger bd = this.denominator.multiply(arg.denominator);
116 return new Rational(ac,bd);
117 }
118
119 public Rational div(Rational arg)
120 {
121 BigInteger ad = this.numerator.multiply(arg.denominator);
122 BigInteger bc = this.denominator.multiply(arg.numerator);
123 return new Rational(ad,bc);
124 }
125
126 public Rational pow(Rational arg)
127 {
128 if(!arg.denominator.equals(BigInteger.ONE))
129 throw new ArithmeticException ("Can only raise rationals to integer powers");
130 int exponant = arg.numerator.intValue();
131 if(exponant == 0)
132 return new Rational(BigInteger.ONE);
133 else if(exponant > 0)
134 {
135 BigInteger top = this.numerator.pow(exponant);
136 BigInteger bot = this.denominator.pow(exponant);
137 return new Rational(top,bot);
138 }
139 else
140 { BigInteger top = this.numerator.pow(-exponant);
142 BigInteger bot = this.denominator.pow(-exponant);
143 return new Rational(bot,top);
144 }
145 }
146
147 public Rational negate()
148 {
149 return new Rational(numerator.negate(),denominator);
150 }
151
152 public Rational inverse()
153 {
154 return new Rational(denominator,numerator);
155 }
156
157 public static Number valueOf(String s) {
158 int pos = s.indexOf('/');
159 if(pos==-1) return new Rational(new BigInteger(s));
160 else
161 return new Rational(
162 new BigInteger(s.substring(pos-1)),
163 new BigInteger(s.substring(pos+1,-1)));
164 }
165
168 public BigInteger getDenominator() {
169 return denominator;
170 }
171
172
175 public BigInteger getNumerator() {
176 return numerator;
177 }
178
179 public String toString() {
180 if(denominator.equals(BigInteger.ONE))
181 return numerator.toString();
182 else
183 return numerator.toString() +"/" + denominator.toString();
184 }
185
186 public int compareTo(Object arg)
187 {
188 Rational num = (Rational) arg;
189 if(this.denominator.compareTo(num.denominator) == 0)
190 {
191 return this.numerator.compareTo(num.numerator);
192 }
193 BigInteger ad = this.numerator.multiply(num.denominator);
194 BigInteger bc = this.denominator.multiply(num.numerator);
195 return ad.compareTo(bc);
196 }
197 }
198 |
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