/* |
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* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package sun.misc; |
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import sun.misc.FloatConsts; |
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import sun.misc.DoubleConsts; |
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/** |
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* The class {@code FpUtils} contains static utility methods for |
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* manipulating and inspecting {@code float} and |
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* {@code double} floating-point numbers. These methods include |
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* functionality recommended or required by the IEEE 754 |
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* floating-point standard. |
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* |
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* @author Joseph D. Darcy |
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*/ |
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public class FpUtils { |
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/* |
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* The methods in this class are reasonably implemented using |
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* direct or indirect bit-level manipulation of floating-point |
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* values. However, having access to the IEEE 754 recommended |
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* functions would obviate the need for most programmers to engage |
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* in floating-point bit-twiddling. |
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* |
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* An IEEE 754 number has three fields, from most significant bit |
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* to to least significant, sign, exponent, and significand. |
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* |
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* msb lsb |
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* [sign|exponent| fractional_significand] |
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* |
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* Using some encoding cleverness, explained below, the high order |
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* bit of the logical significand does not need to be explicitly |
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* stored, thus "fractional_significand" instead of simply |
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* "significand" in the figure above. |
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* |
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* For finite normal numbers, the numerical value encoded is |
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* |
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* (-1)^sign * 2^(exponent)*(1.fractional_significand) |
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* |
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* Most finite floating-point numbers are normalized; the exponent |
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* value is reduced until the leading significand bit is 1. |
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* Therefore, the leading 1 is redundant and is not explicitly |
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* stored. If a numerical value is so small it cannot be |
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* normalized, it has a subnormal representation. Subnormal |
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* numbers don't have a leading 1 in their significand; subnormals |
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* are encoding using a special exponent value. In other words, |
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* the high-order bit of the logical significand can be elided in |
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* from the representation in either case since the bit's value is |
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* implicit from the exponent value. |
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* |
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* The exponent field uses a biased representation; if the bits of |
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* the exponent are interpreted as a unsigned integer E, the |
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* exponent represented is E - E_bias where E_bias depends on the |
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* floating-point format. E can range between E_min and E_max, |
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* constants which depend on the floating-point format. E_min and |
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* E_max are -126 and +127 for float, -1022 and +1023 for double. |
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* |
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* The 32-bit float format has 1 sign bit, 8 exponent bits, and 23 |
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* bits for the significand (which is logically 24 bits wide |
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* because of the implicit bit). The 64-bit double format has 1 |
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* sign bit, 11 exponent bits, and 52 bits for the significand |
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* (logically 53 bits). |
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* |
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* Subnormal numbers and zero have the special exponent value |
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* E_min -1; the numerical value represented by a subnormal is: |
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* |
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* (-1)^sign * 2^(E_min)*(0.fractional_significand) |
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* |
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* Zero is represented by all zero bits in the exponent and all |
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* zero bits in the significand; zero can have either sign. |
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* |
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* Infinity and NaN are encoded using the exponent value E_max + |
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* 1. Signed infinities have all significand bits zero; NaNs have |
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* at least one non-zero significand bit. |
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* |
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* The details of IEEE 754 floating-point encoding will be used in |
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* the methods below without further comment. For further |
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* exposition on IEEE 754 numbers, see "IEEE Standard for Binary |
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* Floating-Point Arithmetic" ANSI/IEEE Std 754-1985 or William |
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* Kahan's "Lecture Notes on the Status of IEEE Standard 754 for |
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* Binary Floating-Point Arithmetic", |
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* http://www.cs.berkeley.edu/~wkahan/ieee754status/ieee754.ps. |
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* |
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* Many of this class's methods are members of the set of IEEE 754 |
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* recommended functions or similar functions recommended or |
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* required by IEEE 754R. Discussion of various implementation |
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* techniques for these functions have occurred in: |
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* |
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* W.J. Cody and Jerome T. Coonen, "Algorithm 772 Functions to |
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* Support the IEEE Standard for Binary Floating-Point |
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* Arithmetic," ACM Transactions on Mathematical Software, |
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* vol. 19, no. 4, December 1993, pp. 443-451. |
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* |
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* Joseph D. Darcy, "Writing robust IEEE recommended functions in |
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* ``100% Pure Java''(TM)," University of California, Berkeley |
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* technical report UCB//CSD-98-1009. |
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*/ |
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/** |
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* Don't let anyone instantiate this class. |
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*/ |
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private FpUtils() {} |
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// Helper Methods |
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// The following helper methods are used in the implementation of |
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// the public recommended functions; they generally omit certain |
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// tests for exception cases. |
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/** |
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* Returns unbiased exponent of a {@code double}. |
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* @deprecated Use Math.getExponent. |
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*/ |
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@Deprecated |
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public static int getExponent(double d){ |
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return Math.getExponent(d); |
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} |
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/** |
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* Returns unbiased exponent of a {@code float}. |
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* @deprecated Use Math.getExponent. |
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*/ |
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@Deprecated |
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public static int getExponent(float f){ |
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return Math.getExponent(f); |
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} |
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/** |
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* Returns the first floating-point argument with the sign of the |
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* second floating-point argument. Note that unlike the {@link |
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* FpUtils#copySign(double, double) copySign} method, this method |
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* does not require NaN {@code sign} arguments to be treated |
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* as positive values; implementations are permitted to treat some |
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* NaN arguments as positive and other NaN arguments as negative |
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* to allow greater performance. |
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* |
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* @param magnitude the parameter providing the magnitude of the result |
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* @param sign the parameter providing the sign of the result |
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* @return a value with the magnitude of {@code magnitude} |
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* and the sign of {@code sign}. |
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* @author Joseph D. Darcy |
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* @deprecated Use Math.copySign. |
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*/ |
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@Deprecated |
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public static double rawCopySign(double magnitude, double sign) { |
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return Math.copySign(magnitude, sign); |
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} |
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/** |
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* Returns the first floating-point argument with the sign of the |
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* second floating-point argument. Note that unlike the {@link |
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* FpUtils#copySign(float, float) copySign} method, this method |
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* does not require NaN {@code sign} arguments to be treated |
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* as positive values; implementations are permitted to treat some |
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* NaN arguments as positive and other NaN arguments as negative |
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* to allow greater performance. |
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* |
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* @param magnitude the parameter providing the magnitude of the result |
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* @param sign the parameter providing the sign of the result |
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* @return a value with the magnitude of {@code magnitude} |
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* and the sign of {@code sign}. |
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* @author Joseph D. Darcy |
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* @deprecated Use Math.copySign. |
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*/ |
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@Deprecated |
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public static float rawCopySign(float magnitude, float sign) { |
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return Math.copySign(magnitude, sign); |
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} |
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/* ***************************************************************** */ |
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/** |
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* Returns {@code true} if the argument is a finite |
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* floating-point value; returns {@code false} otherwise (for |
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* NaN and infinity arguments). |
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* |
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* @param d the {@code double} value to be tested |
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* @return {@code true} if the argument is a finite |
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* floating-point value, {@code false} otherwise. |
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* @deprecated Use Double.isFinite. |
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*/ |
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@Deprecated |
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public static boolean isFinite(double d) { |
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return Double.isFinite(d); |
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} |
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/** |
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* Returns {@code true} if the argument is a finite |
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* floating-point value; returns {@code false} otherwise (for |
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* NaN and infinity arguments). |
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* |
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* @param f the {@code float} value to be tested |
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* @return {@code true} if the argument is a finite |
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* floating-point value, {@code false} otherwise. |
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* @deprecated Use Float.isFinite. |
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*/ |
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@Deprecated |
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public static boolean isFinite(float f) { |
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return Float.isFinite(f); |
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} |
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/** |
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* Returns {@code true} if the specified number is infinitely |
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* large in magnitude, {@code false} otherwise. |
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* |
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* <p>Note that this method is equivalent to the {@link |
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* Double#isInfinite(double) Double.isInfinite} method; the |
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* functionality is included in this class for convenience. |
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* |
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* @param d the value to be tested. |
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* @return {@code true} if the value of the argument is positive |
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* infinity or negative infinity; {@code false} otherwise. |
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*/ |
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public static boolean isInfinite(double d) { |
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return Double.isInfinite(d); |
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} |
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/** |
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* Returns {@code true} if the specified number is infinitely |
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* large in magnitude, {@code false} otherwise. |
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* |
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* <p>Note that this method is equivalent to the {@link |
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* Float#isInfinite(float) Float.isInfinite} method; the |
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* functionality is included in this class for convenience. |
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* |
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* @param f the value to be tested. |
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* @return {@code true} if the argument is positive infinity or |
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* negative infinity; {@code false} otherwise. |
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*/ |
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public static boolean isInfinite(float f) { |
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return Float.isInfinite(f); |
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} |
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/** |
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* Returns {@code true} if the specified number is a |
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* Not-a-Number (NaN) value, {@code false} otherwise. |
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* |
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* <p>Note that this method is equivalent to the {@link |
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* Double#isNaN(double) Double.isNaN} method; the functionality is |
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* included in this class for convenience. |
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* |
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* @param d the value to be tested. |
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* @return {@code true} if the value of the argument is NaN; |
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* {@code false} otherwise. |
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*/ |
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public static boolean isNaN(double d) { |
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return Double.isNaN(d); |
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} |
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/** |
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* Returns {@code true} if the specified number is a |
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* Not-a-Number (NaN) value, {@code false} otherwise. |
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* |
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* <p>Note that this method is equivalent to the {@link |
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* Float#isNaN(float) Float.isNaN} method; the functionality is |
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* included in this class for convenience. |
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* |
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* @param f the value to be tested. |
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* @return {@code true} if the argument is NaN; |
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* {@code false} otherwise. |
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*/ |
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public static boolean isNaN(float f) { |
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return Float.isNaN(f); |
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} |
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/** |
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* Returns {@code true} if the unordered relation holds |
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* between the two arguments. When two floating-point values are |
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* unordered, one value is neither less than, equal to, nor |
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* greater than the other. For the unordered relation to be true, |
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* at least one argument must be a {@code NaN}. |
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* |
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* @param arg1 the first argument |
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* @param arg2 the second argument |
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* @return {@code true} if at least one argument is a NaN, |
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* {@code false} otherwise. |
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*/ |
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public static boolean isUnordered(double arg1, double arg2) { |
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return isNaN(arg1) || isNaN(arg2); |
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} |
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/** |
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* Returns {@code true} if the unordered relation holds |
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* between the two arguments. When two floating-point values are |
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* unordered, one value is neither less than, equal to, nor |
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* greater than the other. For the unordered relation to be true, |
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* at least one argument must be a {@code NaN}. |
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* |
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* @param arg1 the first argument |
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* @param arg2 the second argument |
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* @return {@code true} if at least one argument is a NaN, |
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* {@code false} otherwise. |
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*/ |
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public static boolean isUnordered(float arg1, float arg2) { |
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return isNaN(arg1) || isNaN(arg2); |
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} |
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/** |
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* Returns unbiased exponent of a {@code double}; for |
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* subnormal values, the number is treated as if it were |
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* normalized. That is for all finite, non-zero, positive numbers |
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* <i>x</i>, <code>scalb(<i>x</i>, -ilogb(<i>x</i>))</code> is |
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* always in the range [1, 2). |
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* <p> |
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* Special cases: |
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* <ul> |
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* <li> If the argument is NaN, then the result is 2<sup>30</sup>. |
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* <li> If the argument is infinite, then the result is 2<sup>28</sup>. |
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* <li> If the argument is zero, then the result is -(2<sup>28</sup>). |
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* </ul> |
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* |
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* @param d floating-point number whose exponent is to be extracted |
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* @return unbiased exponent of the argument. |
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* @author Joseph D. Darcy |
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*/ |
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public static int ilogb(double d) { |
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int exponent = getExponent(d); |
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switch (exponent) { |
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case DoubleConsts.MAX_EXPONENT+1: // NaN or infinity |
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if( isNaN(d) ) |
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return (1<<30); // 2^30 |
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else // infinite value |
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return (1<<28); // 2^28 |
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case DoubleConsts.MIN_EXPONENT-1: // zero or subnormal |
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if(d == 0.0) { |
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return -(1<<28); // -(2^28) |
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} |
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else { |
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long transducer = Double.doubleToRawLongBits(d); |
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/* |
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* To avoid causing slow arithmetic on subnormals, |
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* the scaling to determine when d's significand |
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* is normalized is done in integer arithmetic. |
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* (there must be at least one "1" bit in the |
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* significand since zero has been screened out. |
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*/ |
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// isolate significand bits |
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transducer &= DoubleConsts.SIGNIF_BIT_MASK; |
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assert(transducer != 0L); |
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// This loop is simple and functional. We might be |
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// able to do something more clever that was faster; |
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// e.g. number of leading zero detection on |
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// (transducer << (# exponent and sign bits). |
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while (transducer < |
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(1L << (DoubleConsts.SIGNIFICAND_WIDTH - 1))) { |
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transducer *= 2; |
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exponent--; |
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} |
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exponent++; |
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assert( exponent >= |
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DoubleConsts.MIN_EXPONENT - (DoubleConsts.SIGNIFICAND_WIDTH-1) && |
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exponent < DoubleConsts.MIN_EXPONENT); |
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return exponent; |
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} |
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default: |
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assert( exponent >= DoubleConsts.MIN_EXPONENT && |
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exponent <= DoubleConsts.MAX_EXPONENT); |
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return exponent; |
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} |
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} |
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/** |
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* Returns unbiased exponent of a {@code float}; for |
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* subnormal values, the number is treated as if it were |
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* normalized. That is for all finite, non-zero, positive numbers |
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* <i>x</i>, <code>scalb(<i>x</i>, -ilogb(<i>x</i>))</code> is |
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* always in the range [1, 2). |
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* <p> |
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* Special cases: |
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* <ul> |
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* <li> If the argument is NaN, then the result is 2<sup>30</sup>. |
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* <li> If the argument is infinite, then the result is 2<sup>28</sup>. |
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* <li> If the argument is zero, then the result is -(2<sup>28</sup>). |
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* </ul> |
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* |
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* @param f floating-point number whose exponent is to be extracted |
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* @return unbiased exponent of the argument. |
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* @author Joseph D. Darcy |
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*/ |
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public static int ilogb(float f) { |
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int exponent = getExponent(f); |
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switch (exponent) { |
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case FloatConsts.MAX_EXPONENT+1: // NaN or infinity |
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if( isNaN(f) ) |
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return (1<<30); // 2^30 |
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else // infinite value |
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return (1<<28); // 2^28 |
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case FloatConsts.MIN_EXPONENT-1: // zero or subnormal |
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if(f == 0.0f) { |
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return -(1<<28); // -(2^28) |
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} |
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else { |
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int transducer = Float.floatToRawIntBits(f); |
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/* |
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* To avoid causing slow arithmetic on subnormals, |
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* the scaling to determine when f's significand |
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* is normalized is done in integer arithmetic. |
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* (there must be at least one "1" bit in the |
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* significand since zero has been screened out. |
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*/ |
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// isolate significand bits |
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transducer &= FloatConsts.SIGNIF_BIT_MASK; |
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assert(transducer != 0); |
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// This loop is simple and functional. We might be |
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// able to do something more clever that was faster; |
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// e.g. number of leading zero detection on |
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// (transducer << (# exponent and sign bits). |
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while (transducer < |
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(1 << (FloatConsts.SIGNIFICAND_WIDTH - 1))) { |
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transducer *= 2; |
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exponent--; |
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} |
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exponent++; |
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assert( exponent >= |
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FloatConsts.MIN_EXPONENT - (FloatConsts.SIGNIFICAND_WIDTH-1) && |
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exponent < FloatConsts.MIN_EXPONENT); |
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return exponent; |
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} |
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default: |
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assert( exponent >= FloatConsts.MIN_EXPONENT && |
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exponent <= FloatConsts.MAX_EXPONENT); |
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return exponent; |
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} |
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} |
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/* |
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* The scalb operation should be reasonably fast; however, there |
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* are tradeoffs in writing a method to minimize the worst case |
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* performance and writing a method to minimize the time for |
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* expected common inputs. Some processors operate very slowly on |
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* subnormal operands, taking hundreds or thousands of cycles for |
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* one floating-point add or multiply as opposed to, say, four |
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* cycles for normal operands. For processors with very slow |
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* subnormal execution, scalb would be fastest if written entirely |
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* with integer operations; in other words, scalb would need to |
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* include the logic of performing correct rounding of subnormal |
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* values. This could be reasonably done in at most a few hundred |
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* cycles. However, this approach may penalize normal operations |
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* since at least the exponent of the floating-point argument must |
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* be examined. |
|
* |
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* The approach taken in this implementation is a compromise. |
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* Floating-point multiplication is used to do most of the work; |
|
* but knowingly multiplying by a subnormal scaling factor is |
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* avoided. However, the floating-point argument is not examined |
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* to see whether or not it is subnormal since subnormal inputs |
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* are assumed to be rare. At most three multiplies are needed to |
|
* scale from the largest to smallest exponent ranges (scaling |
|
* down, at most two multiplies are needed if subnormal scaling |
|
* factors are allowed). However, in this implementation an |
|
* expensive integer remainder operation is avoided at the cost of |
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* requiring five floating-point multiplies in the worst case, |
|
* which should still be a performance win. |
|
* |
|
* If scaling of entire arrays is a concern, it would probably be |
|
* more efficient to provide a double[] scalb(double[], int) |
|
* version of scalb to avoid having to recompute the needed |
|
* scaling factors for each floating-point value. |
|
*/ |
|
/** |
|
* Return {@code d} × |
|
* 2<sup>{@code scale_factor}</sup> rounded as if performed |
|
* by a single correctly rounded floating-point multiply to a |
|
* member of the double value set. See section 4.2.3 of |
|
* <cite>The Java™ Language Specification</cite> |
|
* for a discussion of floating-point |
|
* value sets. If the exponent of the result is between the |
|
* {@code double}'s minimum exponent and maximum exponent, |
|
* the answer is calculated exactly. If the exponent of the |
|
* result would be larger than {@code doubles}'s maximum |
|
* exponent, an infinity is returned. Note that if the result is |
|
* subnormal, precision may be lost; that is, when {@code scalb(x, |
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* n)} is subnormal, {@code scalb(scalb(x, n), -n)} may |
|
* not equal <i>x</i>. When the result is non-NaN, the result has |
|
* the same sign as {@code d}. |
|
* |
|
*<p> |
|
* Special cases: |
|
* <ul> |
|
* <li> If the first argument is NaN, NaN is returned. |
|
* <li> If the first argument is infinite, then an infinity of the |
|
* same sign is returned. |
|
* <li> If the first argument is zero, then a zero of the same |
|
* sign is returned. |
|
* </ul> |
|
* |
|
* @param d number to be scaled by a power of two. |
|
* @param scale_factor power of 2 used to scale {@code d} |
|
* @return {@code d * }2<sup>{@code scale_factor}</sup> |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.scalb. |
|
*/ |
|
@Deprecated |
|
public static double scalb(double d, int scale_factor) { |
|
return Math.scalb(d, scale_factor); |
|
} |
|
/** |
|
* Return {@code f} × |
|
* 2<sup>{@code scale_factor}</sup> rounded as if performed |
|
* by a single correctly rounded floating-point multiply to a |
|
* member of the float value set. See section 4.2.3 of |
|
* <cite>The Java™ Language Specification</cite> |
|
* for a discussion of floating-point |
|
* value sets. If the exponent of the result is between the |
|
* {@code float}'s minimum exponent and maximum exponent, the |
|
* answer is calculated exactly. If the exponent of the result |
|
* would be larger than {@code float}'s maximum exponent, an |
|
* infinity is returned. Note that if the result is subnormal, |
|
* precision may be lost; that is, when {@code scalb(x, n)} |
|
* is subnormal, {@code scalb(scalb(x, n), -n)} may not equal |
|
* <i>x</i>. When the result is non-NaN, the result has the same |
|
* sign as {@code f}. |
|
* |
|
*<p> |
|
* Special cases: |
|
* <ul> |
|
* <li> If the first argument is NaN, NaN is returned. |
|
* <li> If the first argument is infinite, then an infinity of the |
|
* same sign is returned. |
|
* <li> If the first argument is zero, then a zero of the same |
|
* sign is returned. |
|
* </ul> |
|
* |
|
* @param f number to be scaled by a power of two. |
|
* @param scale_factor power of 2 used to scale {@code f} |
|
* @return {@code f * }2<sup>{@code scale_factor}</sup> |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.scalb. |
|
*/ |
|
@Deprecated |
|
public static float scalb(float f, int scale_factor) { |
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return Math.scalb(f, scale_factor); |
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} |
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/** |
|
* Returns the floating-point number adjacent to the first |
|
* argument in the direction of the second argument. If both |
|
* arguments compare as equal the second argument is returned. |
|
* |
|
* <p> |
|
* Special cases: |
|
* <ul> |
|
* <li> If either argument is a NaN, then NaN is returned. |
|
* |
|
* <li> If both arguments are signed zeros, {@code direction} |
|
* is returned unchanged (as implied by the requirement of |
|
* returning the second argument if the arguments compare as |
|
* equal). |
|
* |
|
* <li> If {@code start} is |
|
* ±{@code Double.MIN_VALUE} and {@code direction} |
|
* has a value such that the result should have a smaller |
|
* magnitude, then a zero with the same sign as {@code start} |
|
* is returned. |
|
* |
|
* <li> If {@code start} is infinite and |
|
* {@code direction} has a value such that the result should |
|
* have a smaller magnitude, {@code Double.MAX_VALUE} with the |
|
* same sign as {@code start} is returned. |
|
* |
|
* <li> If {@code start} is equal to ± |
|
* {@code Double.MAX_VALUE} and {@code direction} has a |
|
* value such that the result should have a larger magnitude, an |
|
* infinity with same sign as {@code start} is returned. |
|
* </ul> |
|
* |
|
* @param start starting floating-point value |
|
* @param direction value indicating which of |
|
* {@code start}'s neighbors or {@code start} should |
|
* be returned |
|
* @return The floating-point number adjacent to {@code start} in the |
|
* direction of {@code direction}. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.nextAfter |
|
*/ |
|
@Deprecated |
|
public static double nextAfter(double start, double direction) { |
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return Math.nextAfter(start, direction); |
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} |
|
/** |
|
* Returns the floating-point number adjacent to the first |
|
* argument in the direction of the second argument. If both |
|
* arguments compare as equal, the second argument is returned. |
|
* |
|
* <p> |
|
* Special cases: |
|
* <ul> |
|
* <li> If either argument is a NaN, then NaN is returned. |
|
* |
|
* <li> If both arguments are signed zeros, a {@code float} |
|
* zero with the same sign as {@code direction} is returned |
|
* (as implied by the requirement of returning the second argument |
|
* if the arguments compare as equal). |
|
* |
|
* <li> If {@code start} is |
|
* ±{@code Float.MIN_VALUE} and {@code direction} |
|
* has a value such that the result should have a smaller |
|
* magnitude, then a zero with the same sign as {@code start} |
|
* is returned. |
|
* |
|
* <li> If {@code start} is infinite and |
|
* {@code direction} has a value such that the result should |
|
* have a smaller magnitude, {@code Float.MAX_VALUE} with the |
|
* same sign as {@code start} is returned. |
|
* |
|
* <li> If {@code start} is equal to ± |
|
* {@code Float.MAX_VALUE} and {@code direction} has a |
|
* value such that the result should have a larger magnitude, an |
|
* infinity with same sign as {@code start} is returned. |
|
* </ul> |
|
* |
|
* @param start starting floating-point value |
|
* @param direction value indicating which of |
|
* {@code start}'s neighbors or {@code start} should |
|
* be returned |
|
* @return The floating-point number adjacent to {@code start} in the |
|
* direction of {@code direction}. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.nextAfter. |
|
*/ |
|
@Deprecated |
|
public static float nextAfter(float start, double direction) { |
|
return Math.nextAfter(start, direction); |
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} |
|
/** |
|
* Returns the floating-point value adjacent to {@code d} in |
|
* the direction of positive infinity. This method is |
|
* semantically equivalent to {@code nextAfter(d, |
|
* Double.POSITIVE_INFINITY)}; however, a {@code nextUp} |
|
* implementation may run faster than its equivalent |
|
* {@code nextAfter} call. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, the result is NaN. |
|
* |
|
* <li> If the argument is positive infinity, the result is |
|
* positive infinity. |
|
* |
|
* <li> If the argument is zero, the result is |
|
* {@code Double.MIN_VALUE} |
|
* |
|
* </ul> |
|
* |
|
* @param d starting floating-point value |
|
* @return The adjacent floating-point value closer to positive |
|
* infinity. |
|
* @author Joseph D. Darcy |
|
* @deprecated use Math.nextUp. |
|
*/ |
|
@Deprecated |
|
public static double nextUp(double d) { |
|
return Math.nextUp(d); |
|
} |
|
/** |
|
* Returns the floating-point value adjacent to {@code f} in |
|
* the direction of positive infinity. This method is |
|
* semantically equivalent to {@code nextAfter(f, |
|
* Double.POSITIVE_INFINITY)}; however, a {@code nextUp} |
|
* implementation may run faster than its equivalent |
|
* {@code nextAfter} call. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, the result is NaN. |
|
* |
|
* <li> If the argument is positive infinity, the result is |
|
* positive infinity. |
|
* |
|
* <li> If the argument is zero, the result is |
|
* {@code Float.MIN_VALUE} |
|
* |
|
* </ul> |
|
* |
|
* @param f starting floating-point value |
|
* @return The adjacent floating-point value closer to positive |
|
* infinity. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.nextUp. |
|
*/ |
|
@Deprecated |
|
public static float nextUp(float f) { |
|
return Math.nextUp(f); |
|
} |
|
/** |
|
* Returns the floating-point value adjacent to {@code d} in |
|
* the direction of negative infinity. This method is |
|
* semantically equivalent to {@code nextAfter(d, |
|
* Double.NEGATIVE_INFINITY)}; however, a |
|
* {@code nextDown} implementation may run faster than its |
|
* equivalent {@code nextAfter} call. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, the result is NaN. |
|
* |
|
* <li> If the argument is negative infinity, the result is |
|
* negative infinity. |
|
* |
|
* <li> If the argument is zero, the result is |
|
* {@code -Double.MIN_VALUE} |
|
* |
|
* </ul> |
|
* |
|
* @param d starting floating-point value |
|
* @return The adjacent floating-point value closer to negative |
|
* infinity. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.nextDown. |
|
*/ |
|
@Deprecated |
|
public static double nextDown(double d) { |
|
return Math.nextDown(d); |
|
} |
|
/** |
|
* Returns the floating-point value adjacent to {@code f} in |
|
* the direction of negative infinity. This method is |
|
* semantically equivalent to {@code nextAfter(f, |
|
* Float.NEGATIVE_INFINITY)}; however, a |
|
* {@code nextDown} implementation may run faster than its |
|
* equivalent {@code nextAfter} call. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, the result is NaN. |
|
* |
|
* <li> If the argument is negative infinity, the result is |
|
* negative infinity. |
|
* |
|
* <li> If the argument is zero, the result is |
|
* {@code -Float.MIN_VALUE} |
|
* |
|
* </ul> |
|
* |
|
* @param f starting floating-point value |
|
* @return The adjacent floating-point value closer to negative |
|
* infinity. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use Math.nextDown. |
|
*/ |
|
@Deprecated |
|
public static double nextDown(float f) { |
|
return Math.nextDown(f); |
|
} |
|
/** |
|
* Returns the first floating-point argument with the sign of the |
|
* second floating-point argument. For this method, a NaN |
|
* {@code sign} argument is always treated as if it were |
|
* positive. |
|
* |
|
* @param magnitude the parameter providing the magnitude of the result |
|
* @param sign the parameter providing the sign of the result |
|
* @return a value with the magnitude of {@code magnitude} |
|
* and the sign of {@code sign}. |
|
* @author Joseph D. Darcy |
|
* @since 1.5 |
|
* @deprecated Use StrictMath.copySign. |
|
*/ |
|
@Deprecated |
|
public static double copySign(double magnitude, double sign) { |
|
return StrictMath.copySign(magnitude, sign); |
|
} |
|
/** |
|
* Returns the first floating-point argument with the sign of the |
|
* second floating-point argument. For this method, a NaN |
|
* {@code sign} argument is always treated as if it were |
|
* positive. |
|
* |
|
* @param magnitude the parameter providing the magnitude of the result |
|
* @param sign the parameter providing the sign of the result |
|
* @return a value with the magnitude of {@code magnitude} |
|
* and the sign of {@code sign}. |
|
* @author Joseph D. Darcy |
|
* @deprecated Use StrictMath.copySign. |
|
*/ |
|
@Deprecated |
|
public static float copySign(float magnitude, float sign) { |
|
return StrictMath.copySign(magnitude, sign); |
|
} |
|
/** |
|
* Returns the size of an ulp of the argument. An ulp of a |
|
* {@code double} value is the positive distance between this |
|
* floating-point value and the {@code double} value next |
|
* larger in magnitude. Note that for non-NaN <i>x</i>, |
|
* <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, then the result is NaN. |
|
* <li> If the argument is positive or negative infinity, then the |
|
* result is positive infinity. |
|
* <li> If the argument is positive or negative zero, then the result is |
|
* {@code Double.MIN_VALUE}. |
|
* <li> If the argument is ±{@code Double.MAX_VALUE}, then |
|
* the result is equal to 2<sup>971</sup>. |
|
* </ul> |
|
* |
|
* @param d the floating-point value whose ulp is to be returned |
|
* @return the size of an ulp of the argument |
|
* @author Joseph D. Darcy |
|
* @since 1.5 |
|
* @deprecated Use Math.ulp. |
|
*/ |
|
@Deprecated |
|
public static double ulp(double d) { |
|
return Math.ulp(d); |
|
} |
|
/** |
|
* Returns the size of an ulp of the argument. An ulp of a |
|
* {@code float} value is the positive distance between this |
|
* floating-point value and the {@code float} value next |
|
* larger in magnitude. Note that for non-NaN <i>x</i>, |
|
* <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, then the result is NaN. |
|
* <li> If the argument is positive or negative infinity, then the |
|
* result is positive infinity. |
|
* <li> If the argument is positive or negative zero, then the result is |
|
* {@code Float.MIN_VALUE}. |
|
* <li> If the argument is ±{@code Float.MAX_VALUE}, then |
|
* the result is equal to 2<sup>104</sup>. |
|
* </ul> |
|
* |
|
* @param f the floating-point value whose ulp is to be returned |
|
* @return the size of an ulp of the argument |
|
* @author Joseph D. Darcy |
|
* @since 1.5 |
|
* @deprecated Use Math.ulp. |
|
*/ |
|
@Deprecated |
|
public static float ulp(float f) { |
|
return Math.ulp(f); |
|
} |
|
/** |
|
* Returns the signum function of the argument; zero if the argument |
|
* is zero, 1.0 if the argument is greater than zero, -1.0 if the |
|
* argument is less than zero. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, then the result is NaN. |
|
* <li> If the argument is positive zero or negative zero, then the |
|
* result is the same as the argument. |
|
* </ul> |
|
* |
|
* @param d the floating-point value whose signum is to be returned |
|
* @return the signum function of the argument |
|
* @author Joseph D. Darcy |
|
* @since 1.5 |
|
* @deprecated Use Math.signum. |
|
*/ |
|
@Deprecated |
|
public static double signum(double d) { |
|
return Math.signum(d); |
|
} |
|
/** |
|
* Returns the signum function of the argument; zero if the argument |
|
* is zero, 1.0f if the argument is greater than zero, -1.0f if the |
|
* argument is less than zero. |
|
* |
|
* <p>Special Cases: |
|
* <ul> |
|
* <li> If the argument is NaN, then the result is NaN. |
|
* <li> If the argument is positive zero or negative zero, then the |
|
* result is the same as the argument. |
|
* </ul> |
|
* |
|
* @param f the floating-point value whose signum is to be returned |
|
* @return the signum function of the argument |
|
* @author Joseph D. Darcy |
|
* @since 1.5 |
|
* @deprecated Use Math.signum. |
|
*/ |
|
@Deprecated |
|
public static float signum(float f) { |
|
return Math.signum(f); |
|
} |
|
} |