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1
4 package gnu.math;
5 import java.io.*;
6
7 public class DFloNum extends RealNum implements Externalizable
8 {
9 double value;
10
11 public DFloNum ()
12 {
13 }
14
15 public DFloNum (double value)
16 {
17 this.value = value;
18 }
19
20 public DFloNum (String  s) throws NumberFormatException
21 {
22 Double d = Double.valueOf (s); value = d.doubleValue ();
24
25
32
36 if (value == 0.0 && s.charAt (0) == '-')
38 value = -0.0;
39 }
40
41 public static DFloNum make (double value)
42 {
43 return new DFloNum (value);
44 }
45
46 public final double doubleValue ()
47 {
48 return value;
49 }
50
51 public long longValue ()
52 {
53 return (long) value;
54 }
55
56 public int hashCode ()
57 {
58 return (int)value;
59 }
60
61 public boolean equals (Object obj)
62 {
63 return (obj != null)
65 && (obj instanceof DFloNum)
66 && (Double.doubleToLongBits(((DFloNum)obj).value)
67 == Double.doubleToLongBits(value));
68 }
69
70 public Numeric add (Object y, int k)
71 {
72 if (y instanceof RealNum)
73 return new DFloNum (value + k * ((RealNum)y).doubleValue ());
74 if (!(y instanceof Numeric))
75 throw new IllegalArgumentException ();
76 return ((Numeric)y).addReversed(this, k);
77 }
78
79 public Numeric addReversed (Numeric x, int k)
80 {
81 if (x instanceof RealNum)
82 return new DFloNum (((RealNum)x).doubleValue () + k * value);
83 throw new IllegalArgumentException ();
84 }
85
86 public Numeric mul (Object y)
87 {
88 if (y instanceof RealNum)
89 return new DFloNum (value * ((RealNum)y).doubleValue ());
90 if (!(y instanceof Numeric))
91 throw new IllegalArgumentException ();
92 return ((Numeric)y).mulReversed(this);
93 }
94
95 public Numeric mulReversed (Numeric x)
96 {
97 if (x instanceof RealNum)
98 return new DFloNum (((RealNum)x).doubleValue () * value);
99 throw new IllegalArgumentException ();
100 }
101
102 private static final DFloNum one = new DFloNum(1.0);
103 public static final DFloNum one() { return one; }
104
105 public Numeric div (Object y)
106 {
107 if (y instanceof RealNum)
108 return new DFloNum (value / ((RealNum)y).doubleValue ());
109 if (!(y instanceof Numeric))
110 throw new IllegalArgumentException ();
111 return ((Numeric)y).divReversed(this);
112 }
113
114 public Numeric divReversed (Numeric x)
115 {
116 if (x instanceof RealNum)
117 return new DFloNum (((RealNum)x).doubleValue () / value);
118 throw new IllegalArgumentException ();
119 }
120
121 public Numeric power (IntNum y)
122 {
123 return new DFloNum (Math.pow (doubleValue(), y.doubleValue()));
124 }
125
126 public boolean isNegative ()
127 {
128 return value < 0;
129 }
130
131 public Numeric neg ()
132 {
133 return new DFloNum (-value);
134 }
135
136 public int sign ()
137 {
138 return value > 0.0 ? 1 : value < 0.0 ? -1 : value == 0.0 ? 0: -2;
139 }
140
141 public static int compare (double x, double y)
142 {
143 return x > y ? 1 : x < y ? -1 : x == y ? 0 : -2;
144 }
145
146
147 public static int compare(IntNum x_num, IntNum x_den, double y)
148 {
149 if (Double.isNaN (y))
150 return -2;
151 if (Double.isInfinite (y))
152 {
153 int result = y >= 0.0 ? -1 : 1;
154 if (! x_den.isZero())
155 return result; if (x_num.isZero())
157 return -2; result >>= 1;
159 return x_num.isNegative() ? result : ~result;
160 }
161 else
162 {
163 long bits = Double.doubleToLongBits (y);
164 boolean neg = bits < 0;
165 int exp = (int) (bits >> 52) & 0x7FF;
166 bits &= 0xfffffffffffffL;
167 if (exp == 0)
168 bits <<= 1;
169 else
170 bits |= 0x10000000000000L;
171 IntNum y_num = IntNum.make (neg ? -bits : bits);
172 if (exp >= 1075)
173 y_num = IntNum.shift (y_num, exp - 1075);
174 else
175 x_num = IntNum.shift (x_num, 1075 - exp);
176 return IntNum.compare (x_num, IntNum.times (y_num, x_den));
177 }
178 }
179
180 public int compare (Object obj)
181 {
182 if (obj instanceof RatNum)
183 {
184 RatNum y_rat = (RatNum) obj;
185 int i = compare(y_rat.numerator(), y_rat.denominator(), value);
186 return i < -1 ? i : -i;
187 }
188 return compare (value, ((RealNum)obj).doubleValue ());
189 }
190
191 public int compareReversed (Numeric x)
192 {
193 if (x instanceof RatNum)
194 {
195 RatNum x_rat = (RatNum) x;
196 return compare(x_rat.numerator(), x_rat.denominator(), value);
197 }
198 return compare (((RealNum)x).doubleValue (), value);
199 }
200
201 public boolean isExact ()
202 {
203 return false;
204 }
205
206 public boolean isZero ()
207 {
208 return value == 0.0;
209 }
210
211
212 public static RatNum toExact (double value)
213 {
214 if (Double.isInfinite (value))
215 return RatNum.infinity(value >= 0.0 ? 1 : -1);
216 if (Double.isNaN (value))
217 throw new ArithmeticException ("cannot convert NaN to exact rational");
218 long bits = Double.doubleToLongBits (value);
219 boolean neg = bits < 0;
220 int exp = (int) (bits >> 52) & 0x7FF;
221 bits &= 0xfffffffffffffL;
222 if (exp == 0)
223 bits <<= 1;
224 else
225 bits |= 0x10000000000000L;
226 IntNum mant = IntNum.make (neg ? -bits : bits);
227 if (exp >= 1075)
228 return IntNum.shift (mant, exp - 1075);
229 else
230 return RatNum.make (mant, IntNum.shift (IntNum.one(), 1075 - exp));
231 }
232
233 public String toString ()
234 {
235 return (value == 1.0/0.0 ? "#i1/0"
236 : value == -1.0/0.0 ? "#i-1/0"
237 : Double.isNaN (value) ? "#i0/0"
238 : Double.toString (value));
239 }
240
241 public String toString (int radix)
242 {
243 if (radix == 10)
244 return toString ();
245 return "#d" + toString ();
246 }
247
248
251 public void writeExternal(ObjectOutput out) throws IOException
252 {
253 out.writeDouble(value);
254 }
255
256 public void readExternal(ObjectInput in)
257 throws IOException, ClassNotFoundException
258 {
259 value = in.readDouble();
260 }
261
262
341 }
342 |
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