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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

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1+/*
2+ * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved.
3+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+ *
5+ * This code is free software; you can redistribute it and/or modify it
6+ * under the terms of the GNU General Public License version 2 only, as
7+ * published by the Free Software Foundation. Oracle designates this
8+ * particular file as subject to the "Classpath" exception as provided
9+ * by Oracle in the LICENSE file that accompanied this code.
10+ *
11+ * This code is distributed in the hope that it will be useful, but WITHOUT
12+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14+ * version 2 for more details (a copy is included in the LICENSE file that
15+ * accompanied this code).
16+ *
17+ * You should have received a copy of the GNU General Public License version
18+ * 2 along with this work; if not, write to the Free Software Foundation,
19+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20+ *
21+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22+ * or visit www.oracle.com if you need additional information or have any
23+ * questions.
24+ */
25+
26+package java.lang;
27+import java.util.Random;
28+
29+
30+/**
31+ * The class {@code Math} contains methods for performing basic
32+ * numeric operations such as the elementary exponential, logarithm,
33+ * square root, and trigonometric functions.
34+ *
35+ * <p>Unlike some of the numeric methods of class
36+ * {@code StrictMath}, all implementations of the equivalent
37+ * functions of class {@code Math} are not defined to return the
38+ * bit-for-bit same results. This relaxation permits
39+ * better-performing implementations where strict reproducibility is
40+ * not required.
41+ *
42+ * <p>By default many of the {@code Math} methods simply call
43+ * the equivalent method in {@code StrictMath} for their
44+ * implementation. Code generators are encouraged to use
45+ * platform-specific native libraries or microprocessor instructions,
46+ * where available, to provide higher-performance implementations of
47+ * {@code Math} methods. Such higher-performance
48+ * implementations still must conform to the specification for
49+ * {@code Math}.
50+ *
51+ * <p>The quality of implementation specifications concern two
52+ * properties, accuracy of the returned result and monotonicity of the
53+ * method. Accuracy of the floating-point {@code Math} methods
54+ * is measured in terms of <i>ulps</i>, units in the last place. For
55+ * a given floating-point format, an ulp of a specific real number
56+ * value is the distance between the two floating-point values
57+ * bracketing that numerical value. When discussing the accuracy of a
58+ * method as a whole rather than at a specific argument, the number of
59+ * ulps cited is for the worst-case error at any argument. If a
60+ * method always has an error less than 0.5 ulps, the method always
61+ * returns the floating-point number nearest the exact result; such a
62+ * method is <i>correctly rounded</i>. A correctly rounded method is
63+ * generally the best a floating-point approximation can be; however,
64+ * it is impractical for many floating-point methods to be correctly
65+ * rounded. Instead, for the {@code Math} class, a larger error
66+ * bound of 1 or 2 ulps is allowed for certain methods. Informally,
67+ * with a 1 ulp error bound, when the exact result is a representable
68+ * number, the exact result should be returned as the computed result;
69+ * otherwise, either of the two floating-point values which bracket
70+ * the exact result may be returned. For exact results large in
71+ * magnitude, one of the endpoints of the bracket may be infinite.
72+ * Besides accuracy at individual arguments, maintaining proper
73+ * relations between the method at different arguments is also
74+ * important. Therefore, most methods with more than 0.5 ulp errors
75+ * are required to be <i>semi-monotonic</i>: whenever the mathematical
76+ * function is non-decreasing, so is the floating-point approximation,
77+ * likewise, whenever the mathematical function is non-increasing, so
78+ * is the floating-point approximation. Not all approximations that
79+ * have 1 ulp accuracy will automatically meet the monotonicity
80+ * requirements.
81+ *
82+ * @author unascribed
83+ * @author Joseph D. Darcy
84+ * @since JDK1.0
85+ */
86+
87+public final class Math {
88+
89+ /**
90+ * Don't let anyone instantiate this class.
91+ */
92+ private Math() {}
93+
94+ /**
95+ * The {@code double} value that is closer than any other to
96+ * <i>e</i>, the base of the natural logarithms.
97+ */
98+ public static final double E = 2.7182818284590452354;
99+
100+ /**
101+ * The {@code double} value that is closer than any other to
102+ * <i>pi</i>, the ratio of the circumference of a circle to its
103+ * diameter.
104+ */
105+ public static final double PI = 3.14159265358979323846;
106+
107+ /**
108+ * Returns the trigonometric sine of an angle. Special cases:
109+ * <ul><li>If the argument is NaN or an infinity, then the
110+ * result is NaN.
111+ * <li>If the argument is zero, then the result is a zero with the
112+ * same sign as the argument.</ul>
113+ *
114+ * <p>The computed result must be within 1 ulp of the exact result.
115+ * Results must be semi-monotonic.
116+ *
117+ * @param a an angle, in radians.
118+ * @return the sine of the argument.
119+ */
120+ public static double sin(double a) {
121+ return StrictMath.sin(a); // default impl. delegates to StrictMath
122+ }
123+
124+ /**
125+ * Returns the trigonometric cosine of an angle. Special cases:
126+ * <ul><li>If the argument is NaN or an infinity, then the
127+ * result is NaN.</ul>
128+ *
129+ * <p>The computed result must be within 1 ulp of the exact result.
130+ * Results must be semi-monotonic.
131+ *
132+ * @param a an angle, in radians.
133+ * @return the cosine of the argument.
134+ */
135+ public static double cos(double a) {
136+ return StrictMath.cos(a); // default impl. delegates to StrictMath
137+ }
138+
139+ /**
140+ * Returns the trigonometric tangent of an angle. Special cases:
141+ * <ul><li>If the argument is NaN or an infinity, then the result
142+ * is NaN.
143+ * <li>If the argument is zero, then the result is a zero with the
144+ * same sign as the argument.</ul>
145+ *
146+ * <p>The computed result must be within 1 ulp of the exact result.
147+ * Results must be semi-monotonic.
148+ *
149+ * @param a an angle, in radians.
150+ * @return the tangent of the argument.
151+ */
152+ public static double tan(double a) {
153+ return StrictMath.tan(a); // default impl. delegates to StrictMath
154+ }
155+
156+ /**
157+ * Returns the arc sine of a value; the returned angle is in the
158+ * range -<i>pi</i>/2 through <i>pi</i>/2. Special cases:
159+ * <ul><li>If the argument is NaN or its absolute value is greater
160+ * than 1, then the result is NaN.
161+ * <li>If the argument is zero, then the result is a zero with the
162+ * same sign as the argument.</ul>
163+ *
164+ * <p>The computed result must be within 1 ulp of the exact result.
165+ * Results must be semi-monotonic.
166+ *
167+ * @param a the value whose arc sine is to be returned.
168+ * @return the arc sine of the argument.
169+ */
170+ public static double asin(double a) {
171+ return StrictMath.asin(a); // default impl. delegates to StrictMath
172+ }
173+
174+ /**
175+ * Returns the arc cosine of a value; the returned angle is in the
176+ * range 0.0 through <i>pi</i>. Special case:
177+ * <ul><li>If the argument is NaN or its absolute value is greater
178+ * than 1, then the result is NaN.</ul>
179+ *
180+ * <p>The computed result must be within 1 ulp of the exact result.
181+ * Results must be semi-monotonic.
182+ *
183+ * @param a the value whose arc cosine is to be returned.
184+ * @return the arc cosine of the argument.
185+ */
186+ public static double acos(double a) {
187+ return StrictMath.acos(a); // default impl. delegates to StrictMath
188+ }
189+
190+ /**
191+ * Returns the arc tangent of a value; the returned angle is in the
192+ * range -<i>pi</i>/2 through <i>pi</i>/2. Special cases:
193+ * <ul><li>If the argument is NaN, then the result is NaN.
194+ * <li>If the argument is zero, then the result is a zero with the
195+ * same sign as the argument.</ul>
196+ *
197+ * <p>The computed result must be within 1 ulp of the exact result.
198+ * Results must be semi-monotonic.
199+ *
200+ * @param a the value whose arc tangent is to be returned.
201+ * @return the arc tangent of the argument.
202+ */
203+ public static double atan(double a) {
204+ return StrictMath.atan(a); // default impl. delegates to StrictMath
205+ }
206+
207+ /**
208+ * Converts an angle measured in degrees to an approximately
209+ * equivalent angle measured in radians. The conversion from
210+ * degrees to radians is generally inexact.
211+ *
212+ * @param angdeg an angle, in degrees
213+ * @return the measurement of the angle {@code angdeg}
214+ * in radians.
215+ * @since 1.2
216+ */
217+ public static double toRadians(double angdeg) {
218+ return angdeg / 180.0 * PI;
219+ }
220+
221+ /**
222+ * Converts an angle measured in radians to an approximately
223+ * equivalent angle measured in degrees. The conversion from
224+ * radians to degrees is generally inexact; users should
225+ * <i>not</i> expect {@code cos(toRadians(90.0))} to exactly
226+ * equal {@code 0.0}.
227+ *
228+ * @param angrad an angle, in radians
229+ * @return the measurement of the angle {@code angrad}
230+ * in degrees.
231+ * @since 1.2
232+ */
233+ public static double toDegrees(double angrad) {
234+ return angrad * 180.0 / PI;
235+ }
236+
237+ /**
238+ * Returns Euler's number <i>e</i> raised to the power of a
239+ * {@code double} value. Special cases:
240+ * <ul><li>If the argument is NaN, the result is NaN.
241+ * <li>If the argument is positive infinity, then the result is
242+ * positive infinity.
243+ * <li>If the argument is negative infinity, then the result is
244+ * positive zero.</ul>
245+ *
246+ * <p>The computed result must be within 1 ulp of the exact result.
247+ * Results must be semi-monotonic.
248+ *
249+ * @param a the exponent to raise <i>e</i> to.
250+ * @return the value <i>e</i><sup>{@code a}</sup>,
251+ * where <i>e</i> is the base of the natural logarithms.
252+ */
253+ public static double exp(double a) {
254+ return StrictMath.exp(a); // default impl. delegates to StrictMath
255+ }
256+
257+ /**
258+ * Returns the natural logarithm (base <i>e</i>) of a {@code double}
259+ * value. Special cases:
260+ * <ul><li>If the argument is NaN or less than zero, then the result
261+ * is NaN.
262+ * <li>If the argument is positive infinity, then the result is
263+ * positive infinity.
264+ * <li>If the argument is positive zero or negative zero, then the
265+ * result is negative infinity.</ul>
266+ *
267+ * <p>The computed result must be within 1 ulp of the exact result.
268+ * Results must be semi-monotonic.
269+ *
270+ * @param a a value
271+ * @return the value ln&nbsp;{@code a}, the natural logarithm of
272+ * {@code a}.
273+ */
274+ public static double log(double a) {
275+ return StrictMath.log(a); // default impl. delegates to StrictMath
276+ }
277+
278+ /**
279+ * Returns the base 10 logarithm of a {@code double} value.
280+ * Special cases:
281+ *
282+ * <ul><li>If the argument is NaN or less than zero, then the result
283+ * is NaN.
284+ * <li>If the argument is positive infinity, then the result is
285+ * positive infinity.
286+ * <li>If the argument is positive zero or negative zero, then the
287+ * result is negative infinity.
288+ * <li> If the argument is equal to 10<sup><i>n</i></sup> for
289+ * integer <i>n</i>, then the result is <i>n</i>.
290+ * </ul>
291+ *
292+ * <p>The computed result must be within 1 ulp of the exact result.
293+ * Results must be semi-monotonic.
294+ *
295+ * @param a a value
296+ * @return the base 10 logarithm of {@code a}.
297+ * @since 1.5
298+ */
299+ public static double log10(double a) {
300+ return StrictMath.log10(a); // default impl. delegates to StrictMath
301+ }
302+
303+ /**
304+ * Returns the correctly rounded positive square root of a
305+ * {@code double} value.
306+ * Special cases:
307+ * <ul><li>If the argument is NaN or less than zero, then the result
308+ * is NaN.
309+ * <li>If the argument is positive infinity, then the result is positive
310+ * infinity.
311+ * <li>If the argument is positive zero or negative zero, then the
312+ * result is the same as the argument.</ul>
313+ * Otherwise, the result is the {@code double} value closest to
314+ * the true mathematical square root of the argument value.
315+ *
316+ * @param a a value.
317+ * @return the positive square root of {@code a}.
318+ * If the argument is NaN or less than zero, the result is NaN.
319+ */
320+ public static double sqrt(double a) {
321+ return StrictMath.sqrt(a); // default impl. delegates to StrictMath
322+ // Note that hardware sqrt instructions
323+ // frequently can be directly used by JITs
324+ // and should be much faster than doing
325+ // Math.sqrt in software.
326+ }
327+
328+
329+ /**
330+ * Returns the cube root of a {@code double} value. For
331+ * positive finite {@code x}, {@code cbrt(-x) ==
332+ * -cbrt(x)}; that is, the cube root of a negative value is
333+ * the negative of the cube root of that value's magnitude.
334+ *
335+ * Special cases:
336+ *
337+ * <ul>
338+ *
339+ * <li>If the argument is NaN, then the result is NaN.
340+ *
341+ * <li>If the argument is infinite, then the result is an infinity
342+ * with the same sign as the argument.
343+ *
344+ * <li>If the argument is zero, then the result is a zero with the
345+ * same sign as the argument.
346+ *
347+ * </ul>
348+ *
349+ * <p>The computed result must be within 1 ulp of the exact result.
350+ *
351+ * @param a a value.
352+ * @return the cube root of {@code a}.
353+ * @since 1.5
354+ */
355+ public static double cbrt(double a) {
356+ return StrictMath.cbrt(a);
357+ }
358+
359+ /**
360+ * Computes the remainder operation on two arguments as prescribed
361+ * by the IEEE 754 standard.
362+ * The remainder value is mathematically equal to
363+ * <code>f1&nbsp;-&nbsp;f2</code>&nbsp;&times;&nbsp;<i>n</i>,
364+ * where <i>n</i> is the mathematical integer closest to the exact
365+ * mathematical value of the quotient {@code f1/f2}, and if two
366+ * mathematical integers are equally close to {@code f1/f2},
367+ * then <i>n</i> is the integer that is even. If the remainder is
368+ * zero, its sign is the same as the sign of the first argument.
369+ * Special cases:
370+ * <ul><li>If either argument is NaN, or the first argument is infinite,
371+ * or the second argument is positive zero or negative zero, then the
372+ * result is NaN.
373+ * <li>If the first argument is finite and the second argument is
374+ * infinite, then the result is the same as the first argument.</ul>
375+ *
376+ * @param f1 the dividend.
377+ * @param f2 the divisor.
378+ * @return the remainder when {@code f1} is divided by
379+ * {@code f2}.
380+ */
381+ public static double IEEEremainder(double f1, double f2) {
382+ return StrictMath.IEEEremainder(f1, f2); // delegate to StrictMath
383+ }
384+
385+ /**
386+ * Returns the smallest (closest to negative infinity)
387+ * {@code double} value that is greater than or equal to the
388+ * argument and is equal to a mathematical integer. Special cases:
389+ * <ul><li>If the argument value is already equal to a
390+ * mathematical integer, then the result is the same as the
391+ * argument. <li>If the argument is NaN or an infinity or
392+ * positive zero or negative zero, then the result is the same as
393+ * the argument. <li>If the argument value is less than zero but
394+ * greater than -1.0, then the result is negative zero.</ul> Note
395+ * that the value of {@code Math.ceil(x)} is exactly the
396+ * value of {@code -Math.floor(-x)}.
397+ *
398+ *
399+ * @param a a value.
400+ * @return the smallest (closest to negative infinity)
401+ * floating-point value that is greater than or equal to
402+ * the argument and is equal to a mathematical integer.
403+ */
404+ public static double ceil(double a) {
405+ return StrictMath.ceil(a); // default impl. delegates to StrictMath
406+ }
407+
408+ /**
409+ * Returns the largest (closest to positive infinity)
410+ * {@code double} value that is less than or equal to the
411+ * argument and is equal to a mathematical integer. Special cases:
412+ * <ul><li>If the argument value is already equal to a
413+ * mathematical integer, then the result is the same as the
414+ * argument. <li>If the argument is NaN or an infinity or
415+ * positive zero or negative zero, then the result is the same as
416+ * the argument.</ul>
417+ *
418+ * @param a a value.
419+ * @return the largest (closest to positive infinity)
420+ * floating-point value that less than or equal to the argument
421+ * and is equal to a mathematical integer.
422+ */
423+ public static double floor(double a) {
424+ return StrictMath.floor(a); // default impl. delegates to StrictMath
425+ }
426+
427+ /**
428+ * Returns the {@code double} value that is closest in value
429+ * to the argument and is equal to a mathematical integer. If two
430+ * {@code double} values that are mathematical integers are
431+ * equally close, the result is the integer value that is
432+ * even. Special cases:
433+ * <ul><li>If the argument value is already equal to a mathematical
434+ * integer, then the result is the same as the argument.
435+ * <li>If the argument is NaN or an infinity or positive zero or negative
436+ * zero, then the result is the same as the argument.</ul>
437+ *
438+ * @param a a {@code double} value.
439+ * @return the closest floating-point value to {@code a} that is
440+ * equal to a mathematical integer.
441+ */
442+ public static double rint(double a) {
443+ return StrictMath.rint(a); // default impl. delegates to StrictMath
444+ }
445+
446+ /**
447+ * Returns the angle <i>theta</i> from the conversion of rectangular
448+ * coordinates ({@code x},&nbsp;{@code y}) to polar
449+ * coordinates (r,&nbsp;<i>theta</i>).
450+ * This method computes the phase <i>theta</i> by computing an arc tangent
451+ * of {@code y/x} in the range of -<i>pi</i> to <i>pi</i>. Special
452+ * cases:
453+ * <ul><li>If either argument is NaN, then the result is NaN.
454+ * <li>If the first argument is positive zero and the second argument
455+ * is positive, or the first argument is positive and finite and the
456+ * second argument is positive infinity, then the result is positive
457+ * zero.
458+ * <li>If the first argument is negative zero and the second argument
459+ * is positive, or the first argument is negative and finite and the
460+ * second argument is positive infinity, then the result is negative zero.
461+ * <li>If the first argument is positive zero and the second argument
462+ * is negative, or the first argument is positive and finite and the
463+ * second argument is negative infinity, then the result is the
464+ * {@code double} value closest to <i>pi</i>.
465+ * <li>If the first argument is negative zero and the second argument
466+ * is negative, or the first argument is negative and finite and the
467+ * second argument is negative infinity, then the result is the
468+ * {@code double} value closest to -<i>pi</i>.
469+ * <li>If the first argument is positive and the second argument is
470+ * positive zero or negative zero, or the first argument is positive
471+ * infinity and the second argument is finite, then the result is the
472+ * {@code double} value closest to <i>pi</i>/2.
473+ * <li>If the first argument is negative and the second argument is
474+ * positive zero or negative zero, or the first argument is negative
475+ * infinity and the second argument is finite, then the result is the
476+ * {@code double} value closest to -<i>pi</i>/2.
477+ * <li>If both arguments are positive infinity, then the result is the
478+ * {@code double} value closest to <i>pi</i>/4.
479+ * <li>If the first argument is positive infinity and the second argument
480+ * is negative infinity, then the result is the {@code double}
481+ * value closest to 3*<i>pi</i>/4.
482+ * <li>If the first argument is negative infinity and the second argument
483+ * is positive infinity, then the result is the {@code double} value
484+ * closest to -<i>pi</i>/4.
485+ * <li>If both arguments are negative infinity, then the result is the
486+ * {@code double} value closest to -3*<i>pi</i>/4.</ul>
487+ *
488+ * <p>The computed result must be within 2 ulps of the exact result.
489+ * Results must be semi-monotonic.
490+ *
491+ * @param y the ordinate coordinate
492+ * @param x the abscissa coordinate
493+ * @return the <i>theta</i> component of the point
494+ * (<i>r</i>,&nbsp;<i>theta</i>)
495+ * in polar coordinates that corresponds to the point
496+ * (<i>x</i>,&nbsp;<i>y</i>) in Cartesian coordinates.
497+ */
498+ public static double atan2(double y, double x) {
499+ return StrictMath.atan2(y, x); // default impl. delegates to StrictMath
500+ }
501+
502+ /**
503+ * Returns the value of the first argument raised to the power of the
504+ * second argument. Special cases:
505+ *
506+ * <ul><li>If the second argument is positive or negative zero, then the
507+ * result is 1.0.
508+ * <li>If the second argument is 1.0, then the result is the same as the
509+ * first argument.
510+ * <li>If the second argument is NaN, then the result is NaN.
511+ * <li>If the first argument is NaN and the second argument is nonzero,
512+ * then the result is NaN.
513+ *
514+ * <li>If
515+ * <ul>
516+ * <li>the absolute value of the first argument is greater than 1
517+ * and the second argument is positive infinity, or
518+ * <li>the absolute value of the first argument is less than 1 and
519+ * the second argument is negative infinity,
520+ * </ul>
521+ * then the result is positive infinity.
522+ *
523+ * <li>If
524+ * <ul>
525+ * <li>the absolute value of the first argument is greater than 1 and
526+ * the second argument is negative infinity, or
527+ * <li>the absolute value of the
528+ * first argument is less than 1 and the second argument is positive
529+ * infinity,
530+ * </ul>
531+ * then the result is positive zero.
532+ *
533+ * <li>If the absolute value of the first argument equals 1 and the
534+ * second argument is infinite, then the result is NaN.
535+ *
536+ * <li>If
537+ * <ul>
538+ * <li>the first argument is positive zero and the second argument
539+ * is greater than zero, or
540+ * <li>the first argument is positive infinity and the second
541+ * argument is less than zero,
542+ * </ul>
543+ * then the result is positive zero.
544+ *
545+ * <li>If
546+ * <ul>
547+ * <li>the first argument is positive zero and the second argument
548+ * is less than zero, or
549+ * <li>the first argument is positive infinity and the second
550+ * argument is greater than zero,
551+ * </ul>
552+ * then the result is positive infinity.
553+ *
554+ * <li>If
555+ * <ul>
556+ * <li>the first argument is negative zero and the second argument
557+ * is greater than zero but not a finite odd integer, or
558+ * <li>the first argument is negative infinity and the second
559+ * argument is less than zero but not a finite odd integer,
560+ * </ul>
561+ * then the result is positive zero.
562+ *
563+ * <li>If
564+ * <ul>
565+ * <li>the first argument is negative zero and the second argument
566+ * is a positive finite odd integer, or
567+ * <li>the first argument is negative infinity and the second
568+ * argument is a negative finite odd integer,
569+ * </ul>
570+ * then the result is negative zero.
571+ *
572+ * <li>If
573+ * <ul>
574+ * <li>the first argument is negative zero and the second argument
575+ * is less than zero but not a finite odd integer, or
576+ * <li>the first argument is negative infinity and the second
577+ * argument is greater than zero but not a finite odd integer,
578+ * </ul>
579+ * then the result is positive infinity.
580+ *
581+ * <li>If
582+ * <ul>
583+ * <li>the first argument is negative zero and the second argument
584+ * is a negative finite odd integer, or
585+ * <li>the first argument is negative infinity and the second
586+ * argument is a positive finite odd integer,
587+ * </ul>
588+ * then the result is negative infinity.
589+ *
590+ * <li>If the first argument is finite and less than zero
591+ * <ul>
592+ * <li> if the second argument is a finite even integer, the
593+ * result is equal to the result of raising the absolute value of
594+ * the first argument to the power of the second argument
595+ *
596+ * <li>if the second argument is a finite odd integer, the result
597+ * is equal to the negative of the result of raising the absolute
598+ * value of the first argument to the power of the second
599+ * argument
600+ *
601+ * <li>if the second argument is finite and not an integer, then
602+ * the result is NaN.
603+ * </ul>
604+ *
605+ * <li>If both arguments are integers, then the result is exactly equal
606+ * to the mathematical result of raising the first argument to the power
607+ * of the second argument if that result can in fact be represented
608+ * exactly as a {@code double} value.</ul>
609+ *
610+ * <p>(In the foregoing descriptions, a floating-point value is
611+ * considered to be an integer if and only if it is finite and a
612+ * fixed point of the method {@link #ceil ceil} or,
613+ * equivalently, a fixed point of the method {@link #floor
614+ * floor}. A value is a fixed point of a one-argument
615+ * method if and only if the result of applying the method to the
616+ * value is equal to the value.)
617+ *
618+ * <p>The computed result must be within 1 ulp of the exact result.
619+ * Results must be semi-monotonic.
620+ *
621+ * @param a the base.
622+ * @param b the exponent.
623+ * @return the value {@code a}<sup>{@code b}</sup>.
624+ */
625+ public static double pow(double a, double b) {
626+ return StrictMath.pow(a, b); // default impl. delegates to StrictMath
627+ }
628+
629+ /**
630+ * Returns the closest {@code int} to the argument, with ties
631+ * rounding up.
632+ *
633+ * <p>
634+ * Special cases:
635+ * <ul><li>If the argument is NaN, the result is 0.
636+ * <li>If the argument is negative infinity or any value less than or
637+ * equal to the value of {@code Integer.MIN_VALUE}, the result is
638+ * equal to the value of {@code Integer.MIN_VALUE}.
639+ * <li>If the argument is positive infinity or any value greater than or
640+ * equal to the value of {@code Integer.MAX_VALUE}, the result is
641+ * equal to the value of {@code Integer.MAX_VALUE}.</ul>
642+ *
643+ * @param a a floating-point value to be rounded to an integer.
644+ * @return the value of the argument rounded to the nearest
645+ * {@code int} value.
646+ * @see java.lang.Integer#MAX_VALUE
647+ * @see java.lang.Integer#MIN_VALUE
648+ */
649+ public static int round(float a) {
650+ if (a != 0x1.fffffep-2f) // greatest float value less than 0.5
651+ return (int)floor(a + 0.5f);
652+ else
653+ return 0;
654+ }
655+
656+ /**
657+ * Returns the closest {@code long} to the argument, with ties
658+ * rounding up.
659+ *
660+ * <p>Special cases:
661+ * <ul><li>If the argument is NaN, the result is 0.
662+ * <li>If the argument is negative infinity or any value less than or
663+ * equal to the value of {@code Long.MIN_VALUE}, the result is
664+ * equal to the value of {@code Long.MIN_VALUE}.
665+ * <li>If the argument is positive infinity or any value greater than or
666+ * equal to the value of {@code Long.MAX_VALUE}, the result is
667+ * equal to the value of {@code Long.MAX_VALUE}.</ul>
668+ *
669+ * @param a a floating-point value to be rounded to a
670+ * {@code long}.
671+ * @return the value of the argument rounded to the nearest
672+ * {@code long} value.
673+ * @see java.lang.Long#MAX_VALUE
674+ * @see java.lang.Long#MIN_VALUE
675+ */
676+ public static long round(double a) {
677+ if (a != 0x1.fffffffffffffp-2) // greatest double value less than 0.5
678+ return (long)floor(a + 0.5d);
679+ else
680+ return 0;
681+ }
682+
683+ private static Random randomNumberGenerator;
684+
685+ private static synchronized Random initRNG() {
686+ Random rnd = randomNumberGenerator;
687+ return (rnd == null) ? (randomNumberGenerator = new Random()) : rnd;
688+ }
689+
690+ /**
691+ * Returns a {@code double} value with a positive sign, greater
692+ * than or equal to {@code 0.0} and less than {@code 1.0}.
693+ * Returned values are chosen pseudorandomly with (approximately)
694+ * uniform distribution from that range.
695+ *
696+ * <p>When this method is first called, it creates a single new
697+ * pseudorandom-number generator, exactly as if by the expression
698+ *
699+ * <blockquote>{@code new java.util.Random()}</blockquote>
700+ *
701+ * This new pseudorandom-number generator is used thereafter for
702+ * all calls to this method and is used nowhere else.
703+ *
704+ * <p>This method is properly synchronized to allow correct use by
705+ * more than one thread. However, if many threads need to generate
706+ * pseudorandom numbers at a great rate, it may reduce contention
707+ * for each thread to have its own pseudorandom-number generator.
708+ *
709+ * @return a pseudorandom {@code double} greater than or equal
710+ * to {@code 0.0} and less than {@code 1.0}.
711+ * @see Random#nextDouble()
712+ */
713+ public static double random() {
714+ Random rnd = randomNumberGenerator;
715+ if (rnd == null) rnd = initRNG();
716+ return rnd.nextDouble();
717+ }
718+
719+ /**
720+ * Returns the absolute value of an {@code int} value.
721+ * If the argument is not negative, the argument is returned.
722+ * If the argument is negative, the negation of the argument is returned.
723+ *
724+ * <p>Note that if the argument is equal to the value of
725+ * {@link Integer#MIN_VALUE}, the most negative representable
726+ * {@code int} value, the result is that same value, which is
727+ * negative.
728+ *
729+ * @param a the argument whose absolute value is to be determined
730+ * @return the absolute value of the argument.
731+ */
732+ public static int abs(int a) {
733+ return (a < 0) ? -a : a;
734+ }
735+
736+ /**
737+ * Returns the absolute value of a {@code long} value.
738+ * If the argument is not negative, the argument is returned.
739+ * If the argument is negative, the negation of the argument is returned.
740+ *
741+ * <p>Note that if the argument is equal to the value of
742+ * {@link Long#MIN_VALUE}, the most negative representable
743+ * {@code long} value, the result is that same value, which
744+ * is negative.
745+ *
746+ * @param a the argument whose absolute value is to be determined
747+ * @return the absolute value of the argument.
748+ */
749+ public static long abs(long a) {
750+ return (a < 0) ? -a : a;
751+ }
752+
753+ /**
754+ * Returns the absolute value of a {@code float} value.
755+ * If the argument is not negative, the argument is returned.
756+ * If the argument is negative, the negation of the argument is returned.
757+ * Special cases:
758+ * <ul><li>If the argument is positive zero or negative zero, the
759+ * result is positive zero.
760+ * <li>If the argument is infinite, the result is positive infinity.
761+ * <li>If the argument is NaN, the result is NaN.</ul>
762+ * In other words, the result is the same as the value of the expression:
763+ * <p>{@code Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a))}
764+ *
765+ * @param a the argument whose absolute value is to be determined
766+ * @return the absolute value of the argument.
767+ */
768+ public static float abs(float a) {
769+ return (a <= 0.0F) ? 0.0F - a : a;
770+ }
771+
772+ /**
773+ * Returns the absolute value of a {@code double} value.
774+ * If the argument is not negative, the argument is returned.
775+ * If the argument is negative, the negation of the argument is returned.
776+ * Special cases:
777+ * <ul><li>If the argument is positive zero or negative zero, the result
778+ * is positive zero.
779+ * <li>If the argument is infinite, the result is positive infinity.
780+ * <li>If the argument is NaN, the result is NaN.</ul>
781+ * In other words, the result is the same as the value of the expression:
782+ * <p>{@code Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1)}
783+ *
784+ * @param a the argument whose absolute value is to be determined
785+ * @return the absolute value of the argument.
786+ */
787+ public static double abs(double a) {
788+ return (a <= 0.0D) ? 0.0D - a : a;
789+ }
790+
791+ /**
792+ * Returns the greater of two {@code int} values. That is, the
793+ * result is the argument closer to the value of
794+ * {@link Integer#MAX_VALUE}. If the arguments have the same value,
795+ * the result is that same value.
796+ *
797+ * @param a an argument.
798+ * @param b another argument.
799+ * @return the larger of {@code a} and {@code b}.
800+ */
801+ public static int max(int a, int b) {
802+ return (a >= b) ? a : b;
803+ }
804+
805+ /**
806+ * Returns the greater of two {@code long} values. That is, the
807+ * result is the argument closer to the value of
808+ * {@link Long#MAX_VALUE}. If the arguments have the same value,
809+ * the result is that same value.
810+ *
811+ * @param a an argument.
812+ * @param b another argument.
813+ * @return the larger of {@code a} and {@code b}.
814+ */
815+ public static long max(long a, long b) {
816+ return (a >= b) ? a : b;
817+ }
818+
819+ private static long negativeZeroFloatBits = Float.floatToIntBits(-0.0f);
820+ private static long negativeZeroDoubleBits = Double.doubleToLongBits(-0.0d);
821+
822+ /**
823+ * Returns the greater of two {@code float} values. That is,
824+ * the result is the argument closer to positive infinity. If the
825+ * arguments have the same value, the result is that same
826+ * value. If either value is NaN, then the result is NaN. Unlike
827+ * the numerical comparison operators, this method considers
828+ * negative zero to be strictly smaller than positive zero. If one
829+ * argument is positive zero and the other negative zero, the
830+ * result is positive zero.
831+ *
832+ * @param a an argument.
833+ * @param b another argument.
834+ * @return the larger of {@code a} and {@code b}.
835+ */
836+ public static float max(float a, float b) {
837+ if (a != a) return a; // a is NaN
838+ if ((a == 0.0f) && (b == 0.0f)
839+ && (Float.floatToIntBits(a) == negativeZeroFloatBits)) {
840+ return b;
841+ }
842+ return (a >= b) ? a : b;
843+ }
844+
845+ /**
846+ * Returns the greater of two {@code double} values. That
847+ * is, the result is the argument closer to positive infinity. If
848+ * the arguments have the same value, the result is that same
849+ * value. If either value is NaN, then the result is NaN. Unlike
850+ * the numerical comparison operators, this method considers
851+ * negative zero to be strictly smaller than positive zero. If one
852+ * argument is positive zero and the other negative zero, the
853+ * result is positive zero.
854+ *
855+ * @param a an argument.
856+ * @param b another argument.
857+ * @return the larger of {@code a} and {@code b}.
858+ */
859+ public static double max(double a, double b) {
860+ if (a != a) return a; // a is NaN
861+ if ((a == 0.0d) && (b == 0.0d)
862+ && (Double.doubleToLongBits(a) == negativeZeroDoubleBits)) {
863+ return b;
864+ }
865+ return (a >= b) ? a : b;
866+ }
867+
868+ /**
869+ * Returns the smaller of two {@code int} values. That is,
870+ * the result the argument closer to the value of
871+ * {@link Integer#MIN_VALUE}. If the arguments have the same
872+ * value, the result is that same value.
873+ *
874+ * @param a an argument.
875+ * @param b another argument.
876+ * @return the smaller of {@code a} and {@code b}.
877+ */
878+ public static int min(int a, int b) {
879+ return (a <= b) ? a : b;
880+ }
881+
882+ /**
883+ * Returns the smaller of two {@code long} values. That is,
884+ * the result is the argument closer to the value of
885+ * {@link Long#MIN_VALUE}. If the arguments have the same
886+ * value, the result is that same value.
887+ *
888+ * @param a an argument.
889+ * @param b another argument.
890+ * @return the smaller of {@code a} and {@code b}.
891+ */
892+ public static long min(long a, long b) {
893+ return (a <= b) ? a : b;
894+ }
895+
896+ /**
897+ * Returns the smaller of two {@code float} values. That is,
898+ * the result is the value closer to negative infinity. If the
899+ * arguments have the same value, the result is that same
900+ * value. If either value is NaN, then the result is NaN. Unlike
901+ * the numerical comparison operators, this method considers
902+ * negative zero to be strictly smaller than positive zero. If
903+ * one argument is positive zero and the other is negative zero,
904+ * the result is negative zero.
905+ *
906+ * @param a an argument.
907+ * @param b another argument.
908+ * @return the smaller of {@code a} and {@code b}.
909+ */
910+ public static float min(float a, float b) {
911+ if (a != a) return a; // a is NaN
912+ if ((a == 0.0f) && (b == 0.0f)
913+ && (Float.floatToIntBits(b) == negativeZeroFloatBits)) {
914+ return b;
915+ }
916+ return (a <= b) ? a : b;
917+ }
918+
919+ /**
920+ * Returns the smaller of two {@code double} values. That
921+ * is, the result is the value closer to negative infinity. If the
922+ * arguments have the same value, the result is that same
923+ * value. If either value is NaN, then the result is NaN. Unlike
924+ * the numerical comparison operators, this method considers
925+ * negative zero to be strictly smaller than positive zero. If one
926+ * argument is positive zero and the other is negative zero, the
927+ * result is negative zero.
928+ *
929+ * @param a an argument.
930+ * @param b another argument.
931+ * @return the smaller of {@code a} and {@code b}.
932+ */
933+ public static double min(double a, double b) {
934+ if (a != a) return a; // a is NaN
935+ if ((a == 0.0d) && (b == 0.0d)
936+ && (Double.doubleToLongBits(b) == negativeZeroDoubleBits)) {
937+ return b;
938+ }
939+ return (a <= b) ? a : b;
940+ }
941+
942+ /**
943+ * Returns the size of an ulp of the argument. An ulp of a
944+ * {@code double} value is the positive distance between this
945+ * floating-point value and the {@code double} value next
946+ * larger in magnitude. Note that for non-NaN <i>x</i>,
947+ * <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
948+ *
949+ * <p>Special Cases:
950+ * <ul>
951+ * <li> If the argument is NaN, then the result is NaN.
952+ * <li> If the argument is positive or negative infinity, then the
953+ * result is positive infinity.
954+ * <li> If the argument is positive or negative zero, then the result is
955+ * {@code Double.MIN_VALUE}.
956+ * <li> If the argument is &plusmn;{@code Double.MAX_VALUE}, then
957+ * the result is equal to 2<sup>971</sup>.
958+ * </ul>
959+ *
960+ * @param d the floating-point value whose ulp is to be returned
961+ * @return the size of an ulp of the argument
962+ * @author Joseph D. Darcy
963+ * @since 1.5
964+ */
965+ public static double ulp(double d) {
966+ return sun.misc.FpUtils.ulp(d);
967+ }
968+
969+ /**
970+ * Returns the size of an ulp of the argument. An ulp of a
971+ * {@code float} value is the positive distance between this
972+ * floating-point value and the {@code float} value next
973+ * larger in magnitude. Note that for non-NaN <i>x</i>,
974+ * <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
975+ *
976+ * <p>Special Cases:
977+ * <ul>
978+ * <li> If the argument is NaN, then the result is NaN.
979+ * <li> If the argument is positive or negative infinity, then the
980+ * result is positive infinity.
981+ * <li> If the argument is positive or negative zero, then the result is
982+ * {@code Float.MIN_VALUE}.
983+ * <li> If the argument is &plusmn;{@code Float.MAX_VALUE}, then
984+ * the result is equal to 2<sup>104</sup>.
985+ * </ul>
986+ *
987+ * @param f the floating-point value whose ulp is to be returned
988+ * @return the size of an ulp of the argument
989+ * @author Joseph D. Darcy
990+ * @since 1.5
991+ */
992+ public static float ulp(float f) {
993+ return sun.misc.FpUtils.ulp(f);
994+ }
995+
996+ /**
997+ * Returns the signum function of the argument; zero if the argument
998+ * is zero, 1.0 if the argument is greater than zero, -1.0 if the
999+ * argument is less than zero.
1000+ *
1001+ * <p>Special Cases:
1002+ * <ul>
1003+ * <li> If the argument is NaN, then the result is NaN.
1004+ * <li> If the argument is positive zero or negative zero, then the
1005+ * result is the same as the argument.
1006+ * </ul>
1007+ *
1008+ * @param d the floating-point value whose signum is to be returned
1009+ * @return the signum function of the argument
1010+ * @author Joseph D. Darcy
1011+ * @since 1.5
1012+ */
1013+ public static double signum(double d) {
1014+ return sun.misc.FpUtils.signum(d);
1015+ }
1016+
1017+ /**
1018+ * Returns the signum function of the argument; zero if the argument
1019+ * is zero, 1.0f if the argument is greater than zero, -1.0f if the
1020+ * argument is less than zero.
1021+ *
1022+ * <p>Special Cases:
1023+ * <ul>
1024+ * <li> If the argument is NaN, then the result is NaN.
1025+ * <li> If the argument is positive zero or negative zero, then the
1026+ * result is the same as the argument.
1027+ * </ul>
1028+ *
1029+ * @param f the floating-point value whose signum is to be returned
1030+ * @return the signum function of the argument
1031+ * @author Joseph D. Darcy
1032+ * @since 1.5
1033+ */
1034+ public static float signum(float f) {
1035+ return sun.misc.FpUtils.signum(f);
1036+ }
1037+
1038+ /**
1039+ * Returns the hyperbolic sine of a {@code double} value.
1040+ * The hyperbolic sine of <i>x</i> is defined to be
1041+ * (<i>e<sup>x</sup>&nbsp;-&nbsp;e<sup>-x</sup></i>)/2
1042+ * where <i>e</i> is {@linkplain Math#E Euler's number}.
1043+ *
1044+ * <p>Special cases:
1045+ * <ul>
1046+ *
1047+ * <li>If the argument is NaN, then the result is NaN.
1048+ *
1049+ * <li>If the argument is infinite, then the result is an infinity
1050+ * with the same sign as the argument.
1051+ *
1052+ * <li>If the argument is zero, then the result is a zero with the
1053+ * same sign as the argument.
1054+ *
1055+ * </ul>
1056+ *
1057+ * <p>The computed result must be within 2.5 ulps of the exact result.
1058+ *
1059+ * @param x The number whose hyperbolic sine is to be returned.
1060+ * @return The hyperbolic sine of {@code x}.
1061+ * @since 1.5
1062+ */
1063+ public static double sinh(double x) {
1064+ return StrictMath.sinh(x);
1065+ }
1066+
1067+ /**
1068+ * Returns the hyperbolic cosine of a {@code double} value.
1069+ * The hyperbolic cosine of <i>x</i> is defined to be
1070+ * (<i>e<sup>x</sup>&nbsp;+&nbsp;e<sup>-x</sup></i>)/2
1071+ * where <i>e</i> is {@linkplain Math#E Euler's number}.
1072+ *
1073+ * <p>Special cases:
1074+ * <ul>
1075+ *
1076+ * <li>If the argument is NaN, then the result is NaN.
1077+ *
1078+ * <li>If the argument is infinite, then the result is positive
1079+ * infinity.
1080+ *
1081+ * <li>If the argument is zero, then the result is {@code 1.0}.
1082+ *
1083+ * </ul>
1084+ *
1085+ * <p>The computed result must be within 2.5 ulps of the exact result.
1086+ *
1087+ * @param x The number whose hyperbolic cosine is to be returned.
1088+ * @return The hyperbolic cosine of {@code x}.
1089+ * @since 1.5
1090+ */
1091+ public static double cosh(double x) {
1092+ return StrictMath.cosh(x);
1093+ }
1094+
1095+ /**
1096+ * Returns the hyperbolic tangent of a {@code double} value.
1097+ * The hyperbolic tangent of <i>x</i> is defined to be
1098+ * (<i>e<sup>x</sup>&nbsp;-&nbsp;e<sup>-x</sup></i>)/(<i>e<sup>x</sup>&nbsp;+&nbsp;e<sup>-x</sup></i>),
1099+ * in other words, {@linkplain Math#sinh
1100+ * sinh(<i>x</i>)}/{@linkplain Math#cosh cosh(<i>x</i>)}. Note
1101+ * that the absolute value of the exact tanh is always less than
1102+ * 1.
1103+ *
1104+ * <p>Special cases:
1105+ * <ul>
1106+ *
1107+ * <li>If the argument is NaN, then the result is NaN.
1108+ *
1109+ * <li>If the argument is zero, then the result is a zero with the
1110+ * same sign as the argument.
1111+ *
1112+ * <li>If the argument is positive infinity, then the result is
1113+ * {@code +1.0}.
1114+ *
1115+ * <li>If the argument is negative infinity, then the result is
1116+ * {@code -1.0}.
1117+ *
1118+ * </ul>
1119+ *
1120+ * <p>The computed result must be within 2.5 ulps of the exact result.
1121+ * The result of {@code tanh} for any finite input must have
1122+ * an absolute value less than or equal to 1. Note that once the
1123+ * exact result of tanh is within 1/2 of an ulp of the limit value
1124+ * of &plusmn;1, correctly signed &plusmn;{@code 1.0} should
1125+ * be returned.
1126+ *
1127+ * @param x The number whose hyperbolic tangent is to be returned.
1128+ * @return The hyperbolic tangent of {@code x}.
1129+ * @since 1.5
1130+ */
1131+ public static double tanh(double x) {
1132+ return StrictMath.tanh(x);
1133+ }
1134+
1135+ /**
1136+ * Returns sqrt(<i>x</i><sup>2</sup>&nbsp;+<i>y</i><sup>2</sup>)
1137+ * without intermediate overflow or underflow.
1138+ *
1139+ * <p>Special cases:
1140+ * <ul>
1141+ *
1142+ * <li> If either argument is infinite, then the result
1143+ * is positive infinity.
1144+ *
1145+ * <li> If either argument is NaN and neither argument is infinite,
1146+ * then the result is NaN.
1147+ *
1148+ * </ul>
1149+ *
1150+ * <p>The computed result must be within 1 ulp of the exact
1151+ * result. If one parameter is held constant, the results must be
1152+ * semi-monotonic in the other parameter.
1153+ *
1154+ * @param x a value
1155+ * @param y a value
1156+ * @return sqrt(<i>x</i><sup>2</sup>&nbsp;+<i>y</i><sup>2</sup>)
1157+ * without intermediate overflow or underflow
1158+ * @since 1.5
1159+ */
1160+ public static double hypot(double x, double y) {
1161+ return StrictMath.hypot(x, y);
1162+ }
1163+
1164+ /**
1165+ * Returns <i>e</i><sup>x</sup>&nbsp;-1. Note that for values of
1166+ * <i>x</i> near 0, the exact sum of
1167+ * {@code expm1(x)}&nbsp;+&nbsp;1 is much closer to the true
1168+ * result of <i>e</i><sup>x</sup> than {@code exp(x)}.
1169+ *
1170+ * <p>Special cases:
1171+ * <ul>
1172+ * <li>If the argument is NaN, the result is NaN.
1173+ *
1174+ * <li>If the argument is positive infinity, then the result is
1175+ * positive infinity.
1176+ *
1177+ * <li>If the argument is negative infinity, then the result is
1178+ * -1.0.
1179+ *
1180+ * <li>If the argument is zero, then the result is a zero with the
1181+ * same sign as the argument.
1182+ *
1183+ * </ul>
1184+ *
1185+ * <p>The computed result must be within 1 ulp of the exact result.
1186+ * Results must be semi-monotonic. The result of
1187+ * {@code expm1} for any finite input must be greater than or
1188+ * equal to {@code -1.0}. Note that once the exact result of
1189+ * <i>e</i><sup>{@code x}</sup>&nbsp;-&nbsp;1 is within 1/2
1190+ * ulp of the limit value -1, {@code -1.0} should be
1191+ * returned.
1192+ *
1193+ * @param x the exponent to raise <i>e</i> to in the computation of
1194+ * <i>e</i><sup>{@code x}</sup>&nbsp;-1.
1195+ * @return the value <i>e</i><sup>{@code x}</sup>&nbsp;-&nbsp;1.
1196+ * @since 1.5
1197+ */
1198+ public static double expm1(double x) {
1199+ return StrictMath.expm1(x);
1200+ }
1201+
1202+ /**
1203+ * Returns the natural logarithm of the sum of the argument and 1.
1204+ * Note that for small values {@code x}, the result of
1205+ * {@code log1p(x)} is much closer to the true result of ln(1
1206+ * + {@code x}) than the floating-point evaluation of
1207+ * {@code log(1.0+x)}.
1208+ *
1209+ * <p>Special cases:
1210+ *
1211+ * <ul>
1212+ *
1213+ * <li>If the argument is NaN or less than -1, then the result is
1214+ * NaN.
1215+ *
1216+ * <li>If the argument is positive infinity, then the result is
1217+ * positive infinity.
1218+ *
1219+ * <li>If the argument is negative one, then the result is
1220+ * negative infinity.
1221+ *
1222+ * <li>If the argument is zero, then the result is a zero with the
1223+ * same sign as the argument.
1224+ *
1225+ * </ul>
1226+ *
1227+ * <p>The computed result must be within 1 ulp of the exact result.
1228+ * Results must be semi-monotonic.
1229+ *
1230+ * @param x a value
1231+ * @return the value ln({@code x}&nbsp;+&nbsp;1), the natural
1232+ * log of {@code x}&nbsp;+&nbsp;1
1233+ * @since 1.5
1234+ */
1235+ public static double log1p(double x) {
1236+ return StrictMath.log1p(x);
1237+ }
1238+
1239+ /**
1240+ * Returns the first floating-point argument with the sign of the
1241+ * second floating-point argument. Note that unlike the {@link
1242+ * StrictMath#copySign(double, double) StrictMath.copySign}
1243+ * method, this method does not require NaN {@code sign}
1244+ * arguments to be treated as positive values; implementations are
1245+ * permitted to treat some NaN arguments as positive and other NaN
1246+ * arguments as negative to allow greater performance.
1247+ *
1248+ * @param magnitude the parameter providing the magnitude of the result
1249+ * @param sign the parameter providing the sign of the result
1250+ * @return a value with the magnitude of {@code magnitude}
1251+ * and the sign of {@code sign}.
1252+ * @since 1.6
1253+ */
1254+ public static double copySign(double magnitude, double sign) {
1255+ return sun.misc.FpUtils.rawCopySign(magnitude, sign);
1256+ }
1257+
1258+ /**
1259+ * Returns the first floating-point argument with the sign of the
1260+ * second floating-point argument. Note that unlike the {@link
1261+ * StrictMath#copySign(float, float) StrictMath.copySign}
1262+ * method, this method does not require NaN {@code sign}
1263+ * arguments to be treated as positive values; implementations are
1264+ * permitted to treat some NaN arguments as positive and other NaN
1265+ * arguments as negative to allow greater performance.
1266+ *
1267+ * @param magnitude the parameter providing the magnitude of the result
1268+ * @param sign the parameter providing the sign of the result
1269+ * @return a value with the magnitude of {@code magnitude}
1270+ * and the sign of {@code sign}.
1271+ * @since 1.6
1272+ */
1273+ public static float copySign(float magnitude, float sign) {
1274+ return sun.misc.FpUtils.rawCopySign(magnitude, sign);
1275+ }
1276+
1277+ /**
1278+ * Returns the unbiased exponent used in the representation of a
1279+ * {@code float}. Special cases:
1280+ *
1281+ * <ul>
1282+ * <li>If the argument is NaN or infinite, then the result is
1283+ * {@link Float#MAX_EXPONENT} + 1.
1284+ * <li>If the argument is zero or subnormal, then the result is
1285+ * {@link Float#MIN_EXPONENT} -1.
1286+ * </ul>
1287+ * @param f a {@code float} value
1288+ * @return the unbiased exponent of the argument
1289+ * @since 1.6
1290+ */
1291+ public static int getExponent(float f) {
1292+ return sun.misc.FpUtils.getExponent(f);
1293+ }
1294+
1295+ /**
1296+ * Returns the unbiased exponent used in the representation of a
1297+ * {@code double}. Special cases:
1298+ *
1299+ * <ul>
1300+ * <li>If the argument is NaN or infinite, then the result is
1301+ * {@link Double#MAX_EXPONENT} + 1.
1302+ * <li>If the argument is zero or subnormal, then the result is
1303+ * {@link Double#MIN_EXPONENT} -1.
1304+ * </ul>
1305+ * @param d a {@code double} value
1306+ * @return the unbiased exponent of the argument
1307+ * @since 1.6
1308+ */
1309+ public static int getExponent(double d) {
1310+ return sun.misc.FpUtils.getExponent(d);
1311+ }
1312+
1313+ /**
1314+ * Returns the floating-point number adjacent to the first
1315+ * argument in the direction of the second argument. If both
1316+ * arguments compare as equal the second argument is returned.
1317+ *
1318+ * <p>
1319+ * Special cases:
1320+ * <ul>
1321+ * <li> If either argument is a NaN, then NaN is returned.
1322+ *
1323+ * <li> If both arguments are signed zeros, {@code direction}
1324+ * is returned unchanged (as implied by the requirement of
1325+ * returning the second argument if the arguments compare as
1326+ * equal).
1327+ *
1328+ * <li> If {@code start} is
1329+ * &plusmn;{@link Double#MIN_VALUE} and {@code direction}
1330+ * has a value such that the result should have a smaller
1331+ * magnitude, then a zero with the same sign as {@code start}
1332+ * is returned.
1333+ *
1334+ * <li> If {@code start} is infinite and
1335+ * {@code direction} has a value such that the result should
1336+ * have a smaller magnitude, {@link Double#MAX_VALUE} with the
1337+ * same sign as {@code start} is returned.
1338+ *
1339+ * <li> If {@code start} is equal to &plusmn;
1340+ * {@link Double#MAX_VALUE} and {@code direction} has a
1341+ * value such that the result should have a larger magnitude, an
1342+ * infinity with same sign as {@code start} is returned.
1343+ * </ul>
1344+ *
1345+ * @param start starting floating-point value
1346+ * @param direction value indicating which of
1347+ * {@code start}'s neighbors or {@code start} should
1348+ * be returned
1349+ * @return The floating-point number adjacent to {@code start} in the
1350+ * direction of {@code direction}.
1351+ * @since 1.6
1352+ */
1353+ public static double nextAfter(double start, double direction) {
1354+ return sun.misc.FpUtils.nextAfter(start, direction);
1355+ }
1356+
1357+ /**
1358+ * Returns the floating-point number adjacent to the first
1359+ * argument in the direction of the second argument. If both
1360+ * arguments compare as equal a value equivalent to the second argument
1361+ * is returned.
1362+ *
1363+ * <p>
1364+ * Special cases:
1365+ * <ul>
1366+ * <li> If either argument is a NaN, then NaN is returned.
1367+ *
1368+ * <li> If both arguments are signed zeros, a value equivalent
1369+ * to {@code direction} is returned.
1370+ *
1371+ * <li> If {@code start} is
1372+ * &plusmn;{@link Float#MIN_VALUE} and {@code direction}
1373+ * has a value such that the result should have a smaller
1374+ * magnitude, then a zero with the same sign as {@code start}
1375+ * is returned.
1376+ *
1377+ * <li> If {@code start} is infinite and
1378+ * {@code direction} has a value such that the result should
1379+ * have a smaller magnitude, {@link Float#MAX_VALUE} with the
1380+ * same sign as {@code start} is returned.
1381+ *
1382+ * <li> If {@code start} is equal to &plusmn;
1383+ * {@link Float#MAX_VALUE} and {@code direction} has a
1384+ * value such that the result should have a larger magnitude, an
1385+ * infinity with same sign as {@code start} is returned.
1386+ * </ul>
1387+ *
1388+ * @param start starting floating-point value
1389+ * @param direction value indicating which of
1390+ * {@code start}'s neighbors or {@code start} should
1391+ * be returned
1392+ * @return The floating-point number adjacent to {@code start} in the
1393+ * direction of {@code direction}.
1394+ * @since 1.6
1395+ */
1396+ public static float nextAfter(float start, double direction) {
1397+ return sun.misc.FpUtils.nextAfter(start, direction);
1398+ }
1399+
1400+ /**
1401+ * Returns the floating-point value adjacent to {@code d} in
1402+ * the direction of positive infinity. This method is
1403+ * semantically equivalent to {@code nextAfter(d,
1404+ * Double.POSITIVE_INFINITY)}; however, a {@code nextUp}
1405+ * implementation may run faster than its equivalent
1406+ * {@code nextAfter} call.
1407+ *
1408+ * <p>Special Cases:
1409+ * <ul>
1410+ * <li> If the argument is NaN, the result is NaN.
1411+ *
1412+ * <li> If the argument is positive infinity, the result is
1413+ * positive infinity.
1414+ *
1415+ * <li> If the argument is zero, the result is
1416+ * {@link Double#MIN_VALUE}
1417+ *
1418+ * </ul>
1419+ *
1420+ * @param d starting floating-point value
1421+ * @return The adjacent floating-point value closer to positive
1422+ * infinity.
1423+ * @since 1.6
1424+ */
1425+ public static double nextUp(double d) {
1426+ return sun.misc.FpUtils.nextUp(d);
1427+ }
1428+
1429+ /**
1430+ * Returns the floating-point value adjacent to {@code f} in
1431+ * the direction of positive infinity. This method is
1432+ * semantically equivalent to {@code nextAfter(f,
1433+ * Float.POSITIVE_INFINITY)}; however, a {@code nextUp}
1434+ * implementation may run faster than its equivalent
1435+ * {@code nextAfter} call.
1436+ *
1437+ * <p>Special Cases:
1438+ * <ul>
1439+ * <li> If the argument is NaN, the result is NaN.
1440+ *
1441+ * <li> If the argument is positive infinity, the result is
1442+ * positive infinity.
1443+ *
1444+ * <li> If the argument is zero, the result is
1445+ * {@link Float#MIN_VALUE}
1446+ *
1447+ * </ul>
1448+ *
1449+ * @param f starting floating-point value
1450+ * @return The adjacent floating-point value closer to positive
1451+ * infinity.
1452+ * @since 1.6
1453+ */
1454+ public static float nextUp(float f) {
1455+ return sun.misc.FpUtils.nextUp(f);
1456+ }
1457+
1458+
1459+ /**
1460+ * Return {@code d} &times;
1461+ * 2<sup>{@code scaleFactor}</sup> rounded as if performed
1462+ * by a single correctly rounded floating-point multiply to a
1463+ * member of the double value set. See the Java
1464+ * Language Specification for a discussion of floating-point
1465+ * value sets. If the exponent of the result is between {@link
1466+ * Double#MIN_EXPONENT} and {@link Double#MAX_EXPONENT}, the
1467+ * answer is calculated exactly. If the exponent of the result
1468+ * would be larger than {@code Double.MAX_EXPONENT}, an
1469+ * infinity is returned. Note that if the result is subnormal,
1470+ * precision may be lost; that is, when {@code scalb(x, n)}
1471+ * is subnormal, {@code scalb(scalb(x, n), -n)} may not equal
1472+ * <i>x</i>. When the result is non-NaN, the result has the same
1473+ * sign as {@code d}.
1474+ *
1475+ * <p>Special cases:
1476+ * <ul>
1477+ * <li> If the first argument is NaN, NaN is returned.
1478+ * <li> If the first argument is infinite, then an infinity of the
1479+ * same sign is returned.
1480+ * <li> If the first argument is zero, then a zero of the same
1481+ * sign is returned.
1482+ * </ul>
1483+ *
1484+ * @param d number to be scaled by a power of two.
1485+ * @param scaleFactor power of 2 used to scale {@code d}
1486+ * @return {@code d} &times; 2<sup>{@code scaleFactor}</sup>
1487+ * @since 1.6
1488+ */
1489+ public static double scalb(double d, int scaleFactor) {
1490+ return sun.misc.FpUtils.scalb(d, scaleFactor);
1491+ }
1492+
1493+ /**
1494+ * Return {@code f} &times;
1495+ * 2<sup>{@code scaleFactor}</sup> rounded as if performed
1496+ * by a single correctly rounded floating-point multiply to a
1497+ * member of the float value set. See the Java
1498+ * Language Specification for a discussion of floating-point
1499+ * value sets. If the exponent of the result is between {@link
1500+ * Float#MIN_EXPONENT} and {@link Float#MAX_EXPONENT}, the
1501+ * answer is calculated exactly. If the exponent of the result
1502+ * would be larger than {@code Float.MAX_EXPONENT}, an
1503+ * infinity is returned. Note that if the result is subnormal,
1504+ * precision may be lost; that is, when {@code scalb(x, n)}
1505+ * is subnormal, {@code scalb(scalb(x, n), -n)} may not equal
1506+ * <i>x</i>. When the result is non-NaN, the result has the same
1507+ * sign as {@code f}.
1508+ *
1509+ * <p>Special cases:
1510+ * <ul>
1511+ * <li> If the first argument is NaN, NaN is returned.
1512+ * <li> If the first argument is infinite, then an infinity of the
1513+ * same sign is returned.
1514+ * <li> If the first argument is zero, then a zero of the same
1515+ * sign is returned.
1516+ * </ul>
1517+ *
1518+ * @param f number to be scaled by a power of two.
1519+ * @param scaleFactor power of 2 used to scale {@code f}
1520+ * @return {@code f} &times; 2<sup>{@code scaleFactor}</sup>
1521+ * @since 1.6
1522+ */
1523+ public static float scalb(float f, int scaleFactor) {
1524+ return sun.misc.FpUtils.scalb(f, scaleFactor);
1525+ }
1526+}

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