| /* |
| * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.lang; |
| import java.util.Random; |
| import sun.misc.DoubleConsts; |
| |
| /** |
| * The class {@code StrictMath} contains methods for performing basic |
| * numeric operations such as the elementary exponential, logarithm, |
| * square root, and trigonometric functions. |
| * |
| * <p>To help ensure portability of Java programs, the definitions of |
| * some of the numeric functions in this package require that they |
| * produce the same results as certain published algorithms. These |
| * algorithms are available from the well-known network library |
| * {@code netlib} as the package "Freely Distributable Math |
| * Library," <a |
| * href="ftp://ftp.netlib.org/fdlibm.tar">{@code fdlibm}</a>. These |
| * algorithms, which are written in the C programming language, are |
| * then to be understood as executed with all floating-point |
| * operations following the rules of Java floating-point arithmetic. |
| * |
| * <p>The Java math library is defined with respect to |
| * {@code fdlibm} version 5.3. Where {@code fdlibm} provides |
| * more than one definition for a function (such as |
| * {@code acos}), use the "IEEE 754 core function" version |
| * (residing in a file whose name begins with the letter |
| * {@code e}). The methods which require {@code fdlibm} |
| * semantics are {@code sin}, {@code cos}, {@code tan}, |
| * {@code asin}, {@code acos}, {@code atan}, |
| * {@code exp}, {@code log}, {@code log10}, |
| * {@code cbrt}, {@code atan2}, {@code pow}, |
| * {@code sinh}, {@code cosh}, {@code tanh}, |
| * {@code hypot}, {@code expm1}, and {@code log1p}. |
| * |
| * <p> |
| * The platform uses signed two's complement integer arithmetic with |
| * int and long primitive types. The developer should choose |
| * the primitive type to ensure that arithmetic operations consistently |
| * produce correct results, which in some cases means the operations |
| * will not overflow the range of values of the computation. |
| * The best practice is to choose the primitive type and algorithm to avoid |
| * overflow. In cases where the size is {@code int} or {@code long} and |
| * overflow errors need to be detected, the methods {@code addExact}, |
| * {@code subtractExact}, {@code multiplyExact}, and {@code toIntExact} |
| * throw an {@code ArithmeticException} when the results overflow. |
| * For other arithmetic operations such as divide, absolute value, |
| * increment, decrement, and negation overflow occurs only with |
| * a specific minimum or maximum value and should be checked against |
| * the minimum or maximum as appropriate. |
| * |
| * @author unascribed |
| * @author Joseph D. Darcy |
| * @since 1.3 |
| */ |
| |
| public final class StrictMath { |
| |
| /** |
| * Don't let anyone instantiate this class. |
| */ |
| private StrictMath() {} |
| |
| /** |
| * The {@code double} value that is closer than any other to |
| * <i>e</i>, the base of the natural logarithms. |
| */ |
| public static final double E = 2.7182818284590452354; |
| |
| /** |
| * The {@code double} value that is closer than any other to |
| * <i>pi</i>, the ratio of the circumference of a circle to its |
| * diameter. |
| */ |
| public static final double PI = 3.14159265358979323846; |
| |
| /** |
| * Returns the trigonometric sine of an angle. Special cases: |
| * <ul><li>If the argument is NaN or an infinity, then the |
| * result is NaN. |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument.</ul> |
| * |
| * @param a an angle, in radians. |
| * @return the sine of the argument. |
| */ |
| public static native double sin(double a); |
| |
| /** |
| * Returns the trigonometric cosine of an angle. Special cases: |
| * <ul><li>If the argument is NaN or an infinity, then the |
| * result is NaN.</ul> |
| * |
| * @param a an angle, in radians. |
| * @return the cosine of the argument. |
| */ |
| public static native double cos(double a); |
| |
| /** |
| * Returns the trigonometric tangent of an angle. Special cases: |
| * <ul><li>If the argument is NaN or an infinity, then the result |
| * is NaN. |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument.</ul> |
| * |
| * @param a an angle, in radians. |
| * @return the tangent of the argument. |
| */ |
| public static native double tan(double a); |
| |
| /** |
| * Returns the arc sine of a value; the returned angle is in the |
| * range -<i>pi</i>/2 through <i>pi</i>/2. Special cases: |
| * <ul><li>If the argument is NaN or its absolute value is greater |
| * than 1, then the result is NaN. |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument.</ul> |
| * |
| * @param a the value whose arc sine is to be returned. |
| * @return the arc sine of the argument. |
| */ |
| public static native double asin(double a); |
| |
| /** |
| * Returns the arc cosine of a value; the returned angle is in the |
| * range 0.0 through <i>pi</i>. Special case: |
| * <ul><li>If the argument is NaN or its absolute value is greater |
| * than 1, then the result is NaN.</ul> |
| * |
| * @param a the value whose arc cosine is to be returned. |
| * @return the arc cosine of the argument. |
| */ |
| public static native double acos(double a); |
| |
| /** |
| * Returns the arc tangent of a value; the returned angle is in the |
| * range -<i>pi</i>/2 through <i>pi</i>/2. Special cases: |
| * <ul><li>If the argument is NaN, then the result is NaN. |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument.</ul> |
| * |
| * @param a the value whose arc tangent is to be returned. |
| * @return the arc tangent of the argument. |
| */ |
| public static native double atan(double a); |
| |
| /** |
| * Converts an angle measured in degrees to an approximately |
| * equivalent angle measured in radians. The conversion from |
| * degrees to radians is generally inexact. |
| * |
| * @param angdeg an angle, in degrees |
| * @return the measurement of the angle {@code angdeg} |
| * in radians. |
| */ |
| public static strictfp double toRadians(double angdeg) { |
| // Do not delegate to Math.toRadians(angdeg) because |
| // this method has the strictfp modifier. |
| return angdeg / 180.0 * PI; |
| } |
| |
| /** |
| * Converts an angle measured in radians to an approximately |
| * equivalent angle measured in degrees. The conversion from |
| * radians to degrees is generally inexact; users should |
| * <i>not</i> expect {@code cos(toRadians(90.0))} to exactly |
| * equal {@code 0.0}. |
| * |
| * @param angrad an angle, in radians |
| * @return the measurement of the angle {@code angrad} |
| * in degrees. |
| */ |
| public static strictfp double toDegrees(double angrad) { |
| // Do not delegate to Math.toDegrees(angrad) because |
| // this method has the strictfp modifier. |
| return angrad * 180.0 / PI; |
| } |
| |
| /** |
| * Returns Euler's number <i>e</i> raised to the power of a |
| * {@code double} value. Special cases: |
| * <ul><li>If the argument is NaN, the result is NaN. |
| * <li>If the argument is positive infinity, then the result is |
| * positive infinity. |
| * <li>If the argument is negative infinity, then the result is |
| * positive zero.</ul> |
| * |
| * @param a the exponent to raise <i>e</i> to. |
| * @return the value <i>e</i><sup>{@code a}</sup>, |
| * where <i>e</i> is the base of the natural logarithms. |
| */ |
| public static native double exp(double a); |
| |
| /** |
| * Returns the natural logarithm (base <i>e</i>) of a {@code double} |
| * value. Special cases: |
| * <ul><li>If the argument is NaN or less than zero, then the result |
| * is NaN. |
| * <li>If the argument is positive infinity, then the result is |
| * positive infinity. |
| * <li>If the argument is positive zero or negative zero, then the |
| * result is negative infinity.</ul> |
| * |
| * @param a a value |
| * @return the value ln {@code a}, the natural logarithm of |
| * {@code a}. |
| */ |
| public static native double log(double a); |
| |
| |
| /** |
| * Returns the base 10 logarithm of a {@code double} value. |
| * Special cases: |
| * |
| * <ul><li>If the argument is NaN or less than zero, then the result |
| * is NaN. |
| * <li>If the argument is positive infinity, then the result is |
| * positive infinity. |
| * <li>If the argument is positive zero or negative zero, then the |
| * result is negative infinity. |
| * <li> If the argument is equal to 10<sup><i>n</i></sup> for |
| * integer <i>n</i>, then the result is <i>n</i>. |
| * </ul> |
| * |
| * @param a a value |
| * @return the base 10 logarithm of {@code a}. |
| * @since 1.5 |
| */ |
| public static native double log10(double a); |
| |
| /** |
| * Returns the correctly rounded positive square root of a |
| * {@code double} value. |
| * Special cases: |
| * <ul><li>If the argument is NaN or less than zero, then the result |
| * is NaN. |
| * <li>If the argument is positive infinity, then the result is positive |
| * infinity. |
| * <li>If the argument is positive zero or negative zero, then the |
| * result is the same as the argument.</ul> |
| * Otherwise, the result is the {@code double} value closest to |
| * the true mathematical square root of the argument value. |
| * |
| * @param a a value. |
| * @return the positive square root of {@code a}. |
| */ |
| public static native double sqrt(double a); |
| |
| /** |
| * Returns the cube root of a {@code double} value. For |
| * positive finite {@code x}, {@code cbrt(-x) == |
| * -cbrt(x)}; that is, the cube root of a negative value is |
| * the negative of the cube root of that value's magnitude. |
| * Special cases: |
| * |
| * <ul> |
| * |
| * <li>If the argument is NaN, then the result is NaN. |
| * |
| * <li>If the argument is infinite, then the result is an infinity |
| * with the same sign as the argument. |
| * |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument. |
| * |
| * </ul> |
| * |
| * @param a a value. |
| * @return the cube root of {@code a}. |
| * @since 1.5 |
| */ |
| public static native double cbrt(double a); |
| |
| /** |
| * Computes the remainder operation on two arguments as prescribed |
| * by the IEEE 754 standard. |
| * The remainder value is mathematically equal to |
| * <code>f1 - f2</code> × <i>n</i>, |
| * where <i>n</i> is the mathematical integer closest to the exact |
| * mathematical value of the quotient {@code f1/f2}, and if two |
| * mathematical integers are equally close to {@code f1/f2}, |
| * then <i>n</i> is the integer that is even. If the remainder is |
| * zero, its sign is the same as the sign of the first argument. |
| * Special cases: |
| * <ul><li>If either argument is NaN, or the first argument is infinite, |
| * or the second argument is positive zero or negative zero, then the |
| * result is NaN. |
| * <li>If the first argument is finite and the second argument is |
| * infinite, then the result is the same as the first argument.</ul> |
| * |
| * @param f1 the dividend. |
| * @param f2 the divisor. |
| * @return the remainder when {@code f1} is divided by |
| * {@code f2}. |
| */ |
| public static native double IEEEremainder(double f1, double f2); |
| |
| /** |
| * Returns the smallest (closest to negative infinity) |
| * {@code double} value that is greater than or equal to the |
| * argument and is equal to a mathematical integer. Special cases: |
| * <ul><li>If the argument value is already equal to a |
| * mathematical integer, then the result is the same as the |
| * argument. <li>If the argument is NaN or an infinity or |
| * positive zero or negative zero, then the result is the same as |
| * the argument. <li>If the argument value is less than zero but |
| * greater than -1.0, then the result is negative zero.</ul> Note |
| * that the value of {@code StrictMath.ceil(x)} is exactly the |
| * value of {@code -StrictMath.floor(-x)}. |
| * |
| * @param a a value. |
| * @return the smallest (closest to negative infinity) |
| * floating-point value that is greater than or equal to |
| * the argument and is equal to a mathematical integer. |
| */ |
| public static double ceil(double a) { |
| return floorOrCeil(a, -0.0, 1.0, 1.0); |
| } |
| |
| /** |
| * Returns the largest (closest to positive infinity) |
| * {@code double} value that is less than or equal to the |
| * argument and is equal to a mathematical integer. Special cases: |
| * <ul><li>If the argument value is already equal to a |
| * mathematical integer, then the result is the same as the |
| * argument. <li>If the argument is NaN or an infinity or |
| * positive zero or negative zero, then the result is the same as |
| * the argument.</ul> |
| * |
| * @param a a value. |
| * @return the largest (closest to positive infinity) |
| * floating-point value that less than or equal to the argument |
| * and is equal to a mathematical integer. |
| */ |
| public static double floor(double a) { |
| return floorOrCeil(a, -1.0, 0.0, -1.0); |
| } |
| |
| /** |
| * Internal method to share logic between floor and ceil. |
| * |
| * @param a the value to be floored or ceiled |
| * @param negativeBoundary result for values in (-1, 0) |
| * @param positiveBoundary result for values in (0, 1) |
| * @param increment value to add when the argument is non-integral |
| */ |
| private static double floorOrCeil(double a, |
| double negativeBoundary, |
| double positiveBoundary, |
| double sign) { |
| int exponent = Math.getExponent(a); |
| |
| if (exponent < 0) { |
| /* |
| * Absolute value of argument is less than 1. |
| * floorOrceil(-0.0) => -0.0 |
| * floorOrceil(+0.0) => +0.0 |
| */ |
| return ((a == 0.0) ? a : |
| ( (a < 0.0) ? negativeBoundary : positiveBoundary) ); |
| } else if (exponent >= 52) { |
| /* |
| * Infinity, NaN, or a value so large it must be integral. |
| */ |
| return a; |
| } |
| // Else the argument is either an integral value already XOR it |
| // has to be rounded to one. |
| assert exponent >= 0 && exponent <= 51; |
| |
| long doppel = Double.doubleToRawLongBits(a); |
| long mask = DoubleConsts.SIGNIF_BIT_MASK >> exponent; |
| |
| if ( (mask & doppel) == 0L ) |
| return a; // integral value |
| else { |
| double result = Double.longBitsToDouble(doppel & (~mask)); |
| if (sign*a > 0.0) |
| result = result + sign; |
| return result; |
| } |
| } |
| |
| /** |
| * Returns the {@code double} value that is closest in value |
| * to the argument and is equal to a mathematical integer. If two |
| * {@code double} values that are mathematical integers are |
| * equally close to the value of the argument, the result is the |
| * integer value that is even. Special cases: |
| * <ul><li>If the argument value is already equal to a mathematical |
| * integer, then the result is the same as the argument. |
| * <li>If the argument is NaN or an infinity or positive zero or negative |
| * zero, then the result is the same as the argument.</ul> |
| * |
| * @param a a value. |
| * @return the closest floating-point value to {@code a} that is |
| * equal to a mathematical integer. |
| * @author Joseph D. Darcy |
| */ |
| public static double rint(double a) { |
| /* |
| * If the absolute value of a is not less than 2^52, it |
| * is either a finite integer (the double format does not have |
| * enough significand bits for a number that large to have any |
| * fractional portion), an infinity, or a NaN. In any of |
| * these cases, rint of the argument is the argument. |
| * |
| * Otherwise, the sum (twoToThe52 + a ) will properly round |
| * away any fractional portion of a since ulp(twoToThe52) == |
| * 1.0; subtracting out twoToThe52 from this sum will then be |
| * exact and leave the rounded integer portion of a. |
| * |
| * This method does *not* need to be declared strictfp to get |
| * fully reproducible results. Whether or not a method is |
| * declared strictfp can only make a difference in the |
| * returned result if some operation would overflow or |
| * underflow with strictfp semantics. The operation |
| * (twoToThe52 + a ) cannot overflow since large values of a |
| * are screened out; the add cannot underflow since twoToThe52 |
| * is too large. The subtraction ((twoToThe52 + a ) - |
| * twoToThe52) will be exact as discussed above and thus |
| * cannot overflow or meaningfully underflow. Finally, the |
| * last multiply in the return statement is by plus or minus |
| * 1.0, which is exact too. |
| */ |
| double twoToThe52 = (double)(1L << 52); // 2^52 |
| double sign = Math.copySign(1.0, a); // preserve sign info |
| a = Math.abs(a); |
| |
| if (a < twoToThe52) { // E_min <= ilogb(a) <= 51 |
| a = ((twoToThe52 + a ) - twoToThe52); |
| } |
| |
| return sign * a; // restore original sign |
| } |
| |
| /** |
| * Returns the angle <i>theta</i> from the conversion of rectangular |
| * coordinates ({@code x}, {@code y}) to polar |
| * coordinates (r, <i>theta</i>). |
| * This method computes the phase <i>theta</i> by computing an arc tangent |
| * of {@code y/x} in the range of -<i>pi</i> to <i>pi</i>. Special |
| * cases: |
| * <ul><li>If either argument is NaN, then the result is NaN. |
| * <li>If the first argument is positive zero and the second argument |
| * is positive, or the first argument is positive and finite and the |
| * second argument is positive infinity, then the result is positive |
| * zero. |
| * <li>If the first argument is negative zero and the second argument |
| * is positive, or the first argument is negative and finite and the |
| * second argument is positive infinity, then the result is negative zero. |
| * <li>If the first argument is positive zero and the second argument |
| * is negative, or the first argument is positive and finite and the |
| * second argument is negative infinity, then the result is the |
| * {@code double} value closest to <i>pi</i>. |
| * <li>If the first argument is negative zero and the second argument |
| * is negative, or the first argument is negative and finite and the |
| * second argument is negative infinity, then the result is the |
| * {@code double} value closest to -<i>pi</i>. |
| * <li>If the first argument is positive and the second argument is |
| * positive zero or negative zero, or the first argument is positive |
| * infinity and the second argument is finite, then the result is the |
| * {@code double} value closest to <i>pi</i>/2. |
| * <li>If the first argument is negative and the second argument is |
| * positive zero or negative zero, or the first argument is negative |
| * infinity and the second argument is finite, then the result is the |
| * {@code double} value closest to -<i>pi</i>/2. |
| * <li>If both arguments are positive infinity, then the result is the |
| * {@code double} value closest to <i>pi</i>/4. |
| * <li>If the first argument is positive infinity and the second argument |
| * is negative infinity, then the result is the {@code double} |
| * value closest to 3*<i>pi</i>/4. |
| * <li>If the first argument is negative infinity and the second argument |
| * is positive infinity, then the result is the {@code double} value |
| * closest to -<i>pi</i>/4. |
| * <li>If both arguments are negative infinity, then the result is the |
| * {@code double} value closest to -3*<i>pi</i>/4.</ul> |
| * |
| * @param y the ordinate coordinate |
| * @param x the abscissa coordinate |
| * @return the <i>theta</i> component of the point |
| * (<i>r</i>, <i>theta</i>) |
| * in polar coordinates that corresponds to the point |
| * (<i>x</i>, <i>y</i>) in Cartesian coordinates. |
| */ |
| public static native double atan2(double y, double x); |
| |
| |
| /** |
| * Returns the value of the first argument raised to the power of the |
| * second argument. Special cases: |
| * |
| * <ul><li>If the second argument is positive or negative zero, then the |
| * result is 1.0. |
| * <li>If the second argument is 1.0, then the result is the same as the |
| * first argument. |
| * <li>If the second argument is NaN, then the result is NaN. |
| * <li>If the first argument is NaN and the second argument is nonzero, |
| * then the result is NaN. |
| * |
| * <li>If |
| * <ul> |
| * <li>the absolute value of the first argument is greater than 1 |
| * and the second argument is positive infinity, or |
| * <li>the absolute value of the first argument is less than 1 and |
| * the second argument is negative infinity, |
| * </ul> |
| * then the result is positive infinity. |
| * |
| * <li>If |
| * <ul> |
| * <li>the absolute value of the first argument is greater than 1 and |
| * the second argument is negative infinity, or |
| * <li>the absolute value of the |
| * first argument is less than 1 and the second argument is positive |
| * infinity, |
| * </ul> |
| * then the result is positive zero. |
| * |
| * <li>If the absolute value of the first argument equals 1 and the |
| * second argument is infinite, then the result is NaN. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is positive zero and the second argument |
| * is greater than zero, or |
| * <li>the first argument is positive infinity and the second |
| * argument is less than zero, |
| * </ul> |
| * then the result is positive zero. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is positive zero and the second argument |
| * is less than zero, or |
| * <li>the first argument is positive infinity and the second |
| * argument is greater than zero, |
| * </ul> |
| * then the result is positive infinity. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is negative zero and the second argument |
| * is greater than zero but not a finite odd integer, or |
| * <li>the first argument is negative infinity and the second |
| * argument is less than zero but not a finite odd integer, |
| * </ul> |
| * then the result is positive zero. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is negative zero and the second argument |
| * is a positive finite odd integer, or |
| * <li>the first argument is negative infinity and the second |
| * argument is a negative finite odd integer, |
| * </ul> |
| * then the result is negative zero. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is negative zero and the second argument |
| * is less than zero but not a finite odd integer, or |
| * <li>the first argument is negative infinity and the second |
| * argument is greater than zero but not a finite odd integer, |
| * </ul> |
| * then the result is positive infinity. |
| * |
| * <li>If |
| * <ul> |
| * <li>the first argument is negative zero and the second argument |
| * is a negative finite odd integer, or |
| * <li>the first argument is negative infinity and the second |
| * argument is a positive finite odd integer, |
| * </ul> |
| * then the result is negative infinity. |
| * |
| * <li>If the first argument is finite and less than zero |
| * <ul> |
| * <li> if the second argument is a finite even integer, the |
| * result is equal to the result of raising the absolute value of |
| * the first argument to the power of the second argument |
| * |
| * <li>if the second argument is a finite odd integer, the result |
| * is equal to the negative of the result of raising the absolute |
| * value of the first argument to the power of the second |
| * argument |
| * |
| * <li>if the second argument is finite and not an integer, then |
| * the result is NaN. |
| * </ul> |
| * |
| * <li>If both arguments are integers, then the result is exactly equal |
| * to the mathematical result of raising the first argument to the power |
| * of the second argument if that result can in fact be represented |
| * exactly as a {@code double} value.</ul> |
| * |
| * <p>(In the foregoing descriptions, a floating-point value is |
| * considered to be an integer if and only if it is finite and a |
| * fixed point of the method {@link #ceil ceil} or, |
| * equivalently, a fixed point of the method {@link #floor |
| * floor}. A value is a fixed point of a one-argument |
| * method if and only if the result of applying the method to the |
| * value is equal to the value.) |
| * |
| * @param a base. |
| * @param b the exponent. |
| * @return the value {@code a}<sup>{@code b}</sup>. |
| */ |
| public static native double pow(double a, double b); |
| |
| /** |
| * Returns the closest {@code int} to the argument, with ties |
| * rounding to positive infinity. |
| * |
| * <p>Special cases: |
| * <ul><li>If the argument is NaN, the result is 0. |
| * <li>If the argument is negative infinity or any value less than or |
| * equal to the value of {@code Integer.MIN_VALUE}, the result is |
| * equal to the value of {@code Integer.MIN_VALUE}. |
| * <li>If the argument is positive infinity or any value greater than or |
| * equal to the value of {@code Integer.MAX_VALUE}, the result is |
| * equal to the value of {@code Integer.MAX_VALUE}.</ul> |
| * |
| * @param a a floating-point value to be rounded to an integer. |
| * @return the value of the argument rounded to the nearest |
| * {@code int} value. |
| * @see java.lang.Integer#MAX_VALUE |
| * @see java.lang.Integer#MIN_VALUE |
| */ |
| public static int round(float a) { |
| return Math.round(a); |
| } |
| |
| /** |
| * Returns the closest {@code long} to the argument, with ties |
| * rounding to positive infinity. |
| * |
| * <p>Special cases: |
| * <ul><li>If the argument is NaN, the result is 0. |
| * <li>If the argument is negative infinity or any value less than or |
| * equal to the value of {@code Long.MIN_VALUE}, the result is |
| * equal to the value of {@code Long.MIN_VALUE}. |
| * <li>If the argument is positive infinity or any value greater than or |
| * equal to the value of {@code Long.MAX_VALUE}, the result is |
| * equal to the value of {@code Long.MAX_VALUE}.</ul> |
| * |
| * @param a a floating-point value to be rounded to a |
| * {@code long}. |
| * @return the value of the argument rounded to the nearest |
| * {@code long} value. |
| * @see java.lang.Long#MAX_VALUE |
| * @see java.lang.Long#MIN_VALUE |
| */ |
| public static long round(double a) { |
| return Math.round(a); |
| } |
| |
| private static final class RandomNumberGeneratorHolder { |
| static final Random randomNumberGenerator = new Random(); |
| } |
| |
| /** |
| * Returns a {@code double} value with a positive sign, greater |
| * than or equal to {@code 0.0} and less than {@code 1.0}. |
| * Returned values are chosen pseudorandomly with (approximately) |
| * uniform distribution from that range. |
| * |
| * <p>When this method is first called, it creates a single new |
| * pseudorandom-number generator, exactly as if by the expression |
| * |
| * <blockquote>{@code new java.util.Random()}</blockquote> |
| * |
| * This new pseudorandom-number generator is used thereafter for |
| * all calls to this method and is used nowhere else. |
| * |
| * <p>This method is properly synchronized to allow correct use by |
| * more than one thread. However, if many threads need to generate |
| * pseudorandom numbers at a great rate, it may reduce contention |
| * for each thread to have its own pseudorandom-number generator. |
| * |
| * @return a pseudorandom {@code double} greater than or equal |
| * to {@code 0.0} and less than {@code 1.0}. |
| * @see Random#nextDouble() |
| */ |
| public static double random() { |
| return RandomNumberGeneratorHolder.randomNumberGenerator.nextDouble(); |
| } |
| |
| /** |
| * Returns the sum of its arguments, |
| * throwing an exception if the result overflows an {@code int}. |
| * |
| * @param x the first value |
| * @param y the second value |
| * @return the result |
| * @throws ArithmeticException if the result overflows an int |
| * @see Math#addExact(int,int) |
| * @since 1.8 |
| */ |
| public static int addExact(int x, int y) { |
| return Math.addExact(x, y); |
| } |
| |
| /** |
| * Returns the sum of its arguments, |
| * throwing an exception if the result overflows a {@code long}. |
| * |
| * @param x the first value |
| * @param y the second value |
| * @return the result |
| * @throws ArithmeticException if the result overflows a long |
| * @see Math#addExact(long,long) |
| * @since 1.8 |
| */ |
| public static long addExact(long x, long y) { |
| return Math.addExact(x, y); |
| } |
| |
| /** |
| * Returns the difference of the arguments, |
| * throwing an exception if the result overflows an {@code int}. |
| * |
| * @param x the first value |
| * @param y the second value to subtract from the first |
| * @return the result |
| * @throws ArithmeticException if the result overflows an int |
| * @see Math#subtractExact(int,int) |
| * @since 1.8 |
| */ |
| public static int subtractExact(int x, int y) { |
| return Math.subtractExact(x, y); |
| } |
| |
| /** |
| * Returns the difference of the arguments, |
| * throwing an exception if the result overflows a {@code long}. |
| * |
| * @param x the first value |
| * @param y the second value to subtract from the first |
| * @return the result |
| * @throws ArithmeticException if the result overflows a long |
| * @see Math#subtractExact(long,long) |
| * @since 1.8 |
| */ |
| public static long subtractExact(long x, long y) { |
| return Math.subtractExact(x, y); |
| } |
| |
| /** |
| * Returns the product of the arguments, |
| * throwing an exception if the result overflows an {@code int}. |
| * |
| * @param x the first value |
| * @param y the second value |
| * @return the result |
| * @throws ArithmeticException if the result overflows an int |
| * @see Math#multiplyExact(int,int) |
| * @since 1.8 |
| */ |
| public static int multiplyExact(int x, int y) { |
| return Math.multiplyExact(x, y); |
| } |
| |
| /** |
| * Returns the product of the arguments, |
| * throwing an exception if the result overflows a {@code long}. |
| * |
| * @param x the first value |
| * @param y the second value |
| * @return the result |
| * @throws ArithmeticException if the result overflows a long |
| * @see Math#multiplyExact(long,long) |
| * @since 1.8 |
| */ |
| public static long multiplyExact(long x, long y) { |
| return Math.multiplyExact(x, y); |
| } |
| |
| /** |
| * Returns the value of the {@code long} argument; |
| * throwing an exception if the value overflows an {@code int}. |
| * |
| * @param value the long value |
| * @return the argument as an int |
| * @throws ArithmeticException if the {@code argument} overflows an int |
| * @see Math#toIntExact(long) |
| * @since 1.8 |
| */ |
| public static int toIntExact(long value) { |
| return Math.toIntExact(value); |
| } |
| |
| /** |
| * Returns the largest (closest to positive infinity) |
| * {@code int} value that is less than or equal to the algebraic quotient. |
| * There is one special case, if the dividend is the |
| * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is {@code -1}, |
| * then integer overflow occurs and |
| * the result is equal to the {@code Integer.MIN_VALUE}. |
| * <p> |
| * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and |
| * a comparison to the integer division {@code /} operator. |
| * |
| * @param x the dividend |
| * @param y the divisor |
| * @return the largest (closest to positive infinity) |
| * {@code int} value that is less than or equal to the algebraic quotient. |
| * @throws ArithmeticException if the divisor {@code y} is zero |
| * @see Math#floorDiv(int, int) |
| * @see Math#floor(double) |
| * @since 1.8 |
| */ |
| public static int floorDiv(int x, int y) { |
| return Math.floorDiv(x, y); |
| } |
| |
| /** |
| * Returns the largest (closest to positive infinity) |
| * {@code long} value that is less than or equal to the algebraic quotient. |
| * There is one special case, if the dividend is the |
| * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1}, |
| * then integer overflow occurs and |
| * the result is equal to the {@code Long.MIN_VALUE}. |
| * <p> |
| * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and |
| * a comparison to the integer division {@code /} operator. |
| * |
| * @param x the dividend |
| * @param y the divisor |
| * @return the largest (closest to positive infinity) |
| * {@code long} value that is less than or equal to the algebraic quotient. |
| * @throws ArithmeticException if the divisor {@code y} is zero |
| * @see Math#floorDiv(long, long) |
| * @see Math#floor(double) |
| * @since 1.8 |
| */ |
| public static long floorDiv(long x, long y) { |
| return Math.floorDiv(x, y); |
| } |
| |
| /** |
| * Returns the floor modulus of the {@code int} arguments. |
| * <p> |
| * The floor modulus is {@code x - (floorDiv(x, y) * y)}, |
| * has the same sign as the divisor {@code y}, and |
| * is in the range of {@code -abs(y) < r < +abs(y)}. |
| * <p> |
| * The relationship between {@code floorDiv} and {@code floorMod} is such that: |
| * <ul> |
| * <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x} |
| * </ul> |
| * <p> |
| * See {@link Math#floorMod(int, int) Math.floorMod} for examples and |
| * a comparison to the {@code %} operator. |
| * |
| * @param x the dividend |
| * @param y the divisor |
| * @return the floor modulus {@code x - (floorDiv(x, y) * y)} |
| * @throws ArithmeticException if the divisor {@code y} is zero |
| * @see Math#floorMod(int, int) |
| * @see StrictMath#floorDiv(int, int) |
| * @since 1.8 |
| */ |
| public static int floorMod(int x, int y) { |
| return Math.floorMod(x , y); |
| } |
| /** |
| * Returns the floor modulus of the {@code long} arguments. |
| * <p> |
| * The floor modulus is {@code x - (floorDiv(x, y) * y)}, |
| * has the same sign as the divisor {@code y}, and |
| * is in the range of {@code -abs(y) < r < +abs(y)}. |
| * <p> |
| * The relationship between {@code floorDiv} and {@code floorMod} is such that: |
| * <ul> |
| * <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x} |
| * </ul> |
| * <p> |
| * See {@link Math#floorMod(int, int) Math.floorMod} for examples and |
| * a comparison to the {@code %} operator. |
| * |
| * @param x the dividend |
| * @param y the divisor |
| * @return the floor modulus {@code x - (floorDiv(x, y) * y)} |
| * @throws ArithmeticException if the divisor {@code y} is zero |
| * @see Math#floorMod(long, long) |
| * @see StrictMath#floorDiv(long, long) |
| * @since 1.8 |
| */ |
| public static long floorMod(long x, long y) { |
| return Math.floorMod(x, y); |
| } |
| |
| /** |
| * Returns the absolute value of an {@code int} value. |
| * If the argument is not negative, the argument is returned. |
| * If the argument is negative, the negation of the argument is returned. |
| * |
| * <p>Note that if the argument is equal to the value of |
| * {@link Integer#MIN_VALUE}, the most negative representable |
| * {@code int} value, the result is that same value, which is |
| * negative. |
| * |
| * @param a the argument whose absolute value is to be determined. |
| * @return the absolute value of the argument. |
| */ |
| public static int abs(int a) { |
| return Math.abs(a); |
| } |
| |
| /** |
| * Returns the absolute value of a {@code long} value. |
| * If the argument is not negative, the argument is returned. |
| * If the argument is negative, the negation of the argument is returned. |
| * |
| * <p>Note that if the argument is equal to the value of |
| * {@link Long#MIN_VALUE}, the most negative representable |
| * {@code long} value, the result is that same value, which |
| * is negative. |
| * |
| * @param a the argument whose absolute value is to be determined. |
| * @return the absolute value of the argument. |
| */ |
| public static long abs(long a) { |
| return Math.abs(a); |
| } |
| |
| /** |
| * Returns the absolute value of a {@code float} value. |
| * If the argument is not negative, the argument is returned. |
| * If the argument is negative, the negation of the argument is returned. |
| * Special cases: |
| * <ul><li>If the argument is positive zero or negative zero, the |
| * result is positive zero. |
| * <li>If the argument is infinite, the result is positive infinity. |
| * <li>If the argument is NaN, the result is NaN.</ul> |
| * In other words, the result is the same as the value of the expression: |
| * <p>{@code Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a))} |
| * |
| * @param a the argument whose absolute value is to be determined |
| * @return the absolute value of the argument. |
| */ |
| public static float abs(float a) { |
| return Math.abs(a); |
| } |
| |
| /** |
| * Returns the absolute value of a {@code double} value. |
| * If the argument is not negative, the argument is returned. |
| * If the argument is negative, the negation of the argument is returned. |
| * Special cases: |
| * <ul><li>If the argument is positive zero or negative zero, the result |
| * is positive zero. |
| * <li>If the argument is infinite, the result is positive infinity. |
| * <li>If the argument is NaN, the result is NaN.</ul> |
| * In other words, the result is the same as the value of the expression: |
| * <p>{@code Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1)} |
| * |
| * @param a the argument whose absolute value is to be determined |
| * @return the absolute value of the argument. |
| */ |
| public static double abs(double a) { |
| return Math.abs(a); |
| } |
| |
| /** |
| * Returns the greater of two {@code int} values. That is, the |
| * result is the argument closer to the value of |
| * {@link Integer#MAX_VALUE}. If the arguments have the same value, |
| * the result is that same value. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the larger of {@code a} and {@code b}. |
| */ |
| public static int max(int a, int b) { |
| return Math.max(a, b); |
| } |
| |
| /** |
| * Returns the greater of two {@code long} values. That is, the |
| * result is the argument closer to the value of |
| * {@link Long#MAX_VALUE}. If the arguments have the same value, |
| * the result is that same value. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the larger of {@code a} and {@code b}. |
| */ |
| public static long max(long a, long b) { |
| return Math.max(a, b); |
| } |
| |
| /** |
| * Returns the greater of two {@code float} values. That is, |
| * the result is the argument closer to positive infinity. If the |
| * arguments have the same value, the result is that same |
| * value. If either value is NaN, then the result is NaN. Unlike |
| * the numerical comparison operators, this method considers |
| * negative zero to be strictly smaller than positive zero. If one |
| * argument is positive zero and the other negative zero, the |
| * result is positive zero. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the larger of {@code a} and {@code b}. |
| */ |
| public static float max(float a, float b) { |
| return Math.max(a, b); |
| } |
| |
| /** |
| * Returns the greater of two {@code double} values. That |
| * is, the result is the argument closer to positive infinity. If |
| * the arguments have the same value, the result is that same |
| * value. If either value is NaN, then the result is NaN. Unlike |
| * the numerical comparison operators, this method considers |
| * negative zero to be strictly smaller than positive zero. If one |
| * argument is positive zero and the other negative zero, the |
| * result is positive zero. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the larger of {@code a} and {@code b}. |
| */ |
| public static double max(double a, double b) { |
| return Math.max(a, b); |
| } |
| |
| /** |
| * Returns the smaller of two {@code int} values. That is, |
| * the result the argument closer to the value of |
| * {@link Integer#MIN_VALUE}. If the arguments have the same |
| * value, the result is that same value. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the smaller of {@code a} and {@code b}. |
| */ |
| public static int min(int a, int b) { |
| return Math.min(a, b); |
| } |
| |
| /** |
| * Returns the smaller of two {@code long} values. That is, |
| * the result is the argument closer to the value of |
| * {@link Long#MIN_VALUE}. If the arguments have the same |
| * value, the result is that same value. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the smaller of {@code a} and {@code b}. |
| */ |
| public static long min(long a, long b) { |
| return Math.min(a, b); |
| } |
| |
| /** |
| * Returns the smaller of two {@code float} values. That is, |
| * the result is the value closer to negative infinity. If the |
| * arguments have the same value, the result is that same |
| * value. If either value is NaN, then the result is NaN. Unlike |
| * the numerical comparison operators, this method considers |
| * negative zero to be strictly smaller than positive zero. If |
| * one argument is positive zero and the other is negative zero, |
| * the result is negative zero. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the smaller of {@code a} and {@code b.} |
| */ |
| public static float min(float a, float b) { |
| return Math.min(a, b); |
| } |
| |
| /** |
| * Returns the smaller of two {@code double} values. That |
| * is, the result is the value closer to negative infinity. If the |
| * arguments have the same value, the result is that same |
| * value. If either value is NaN, then the result is NaN. Unlike |
| * the numerical comparison operators, this method considers |
| * negative zero to be strictly smaller than positive zero. If one |
| * argument is positive zero and the other is negative zero, the |
| * result is negative zero. |
| * |
| * @param a an argument. |
| * @param b another argument. |
| * @return the smaller of {@code a} and {@code b}. |
| */ |
| public static double min(double a, double b) { |
| return Math.min(a, b); |
| } |
| |
| /** |
| * Returns the size of an ulp of the argument. An ulp, unit in |
| * the last place, 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 |
| */ |
| public static double ulp(double d) { |
| return Math.ulp(d); |
| } |
| |
| /** |
| * Returns the size of an ulp of the argument. An ulp, unit in |
| * the last place, 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 |
| */ |
| 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 |
| */ |
| 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 |
| */ |
| public static float signum(float f) { |
| return Math.signum(f); |
| } |
| |
| /** |
| * Returns the hyperbolic sine of a {@code double} value. |
| * The hyperbolic sine of <i>x</i> is defined to be |
| * (<i>e<sup>x</sup> - e<sup>-x</sup></i>)/2 |
| * where <i>e</i> is {@linkplain Math#E Euler's number}. |
| * |
| * <p>Special cases: |
| * <ul> |
| * |
| * <li>If the argument is NaN, then the result is NaN. |
| * |
| * <li>If the argument is infinite, then the result is an infinity |
| * with the same sign as the argument. |
| * |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument. |
| * |
| * </ul> |
| * |
| * @param x The number whose hyperbolic sine is to be returned. |
| * @return The hyperbolic sine of {@code x}. |
| * @since 1.5 |
| */ |
| public static native double sinh(double x); |
| |
| /** |
| * Returns the hyperbolic cosine of a {@code double} value. |
| * The hyperbolic cosine of <i>x</i> is defined to be |
| * (<i>e<sup>x</sup> + e<sup>-x</sup></i>)/2 |
| * where <i>e</i> is {@linkplain Math#E Euler's number}. |
| * |
| * <p>Special cases: |
| * <ul> |
| * |
| * <li>If the argument is NaN, then the result is NaN. |
| * |
| * <li>If the argument is infinite, then the result is positive |
| * infinity. |
| * |
| * <li>If the argument is zero, then the result is {@code 1.0}. |
| * |
| * </ul> |
| * |
| * @param x The number whose hyperbolic cosine is to be returned. |
| * @return The hyperbolic cosine of {@code x}. |
| * @since 1.5 |
| */ |
| public static native double cosh(double x); |
| |
| /** |
| * Returns the hyperbolic tangent of a {@code double} value. |
| * The hyperbolic tangent of <i>x</i> is defined to be |
| * (<i>e<sup>x</sup> - e<sup>-x</sup></i>)/(<i>e<sup>x</sup> + e<sup>-x</sup></i>), |
| * in other words, {@linkplain Math#sinh |
| * sinh(<i>x</i>)}/{@linkplain Math#cosh cosh(<i>x</i>)}. Note |
| * that the absolute value of the exact tanh is always less than |
| * 1. |
| * |
| * <p>Special cases: |
| * <ul> |
| * |
| * <li>If the argument is NaN, then the result is NaN. |
| * |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument. |
| * |
| * <li>If the argument is positive infinity, then the result is |
| * {@code +1.0}. |
| * |
| * <li>If the argument is negative infinity, then the result is |
| * {@code -1.0}. |
| * |
| * </ul> |
| * |
| * @param x The number whose hyperbolic tangent is to be returned. |
| * @return The hyperbolic tangent of {@code x}. |
| * @since 1.5 |
| */ |
| public static native double tanh(double x); |
| |
| /** |
| * Returns sqrt(<i>x</i><sup>2</sup> +<i>y</i><sup>2</sup>) |
| * without intermediate overflow or underflow. |
| * |
| * <p>Special cases: |
| * <ul> |
| * |
| * <li> If either argument is infinite, then the result |
| * is positive infinity. |
| * |
| * <li> If either argument is NaN and neither argument is infinite, |
| * then the result is NaN. |
| * |
| * </ul> |
| * |
| * @param x a value |
| * @param y a value |
| * @return sqrt(<i>x</i><sup>2</sup> +<i>y</i><sup>2</sup>) |
| * without intermediate overflow or underflow |
| * @since 1.5 |
| */ |
| public static native double hypot(double x, double y); |
| |
| /** |
| * Returns <i>e</i><sup>x</sup> -1. Note that for values of |
| * <i>x</i> near 0, the exact sum of |
| * {@code expm1(x)} + 1 is much closer to the true |
| * result of <i>e</i><sup>x</sup> than {@code exp(x)}. |
| * |
| * <p>Special cases: |
| * <ul> |
| * <li>If the argument is NaN, the result is NaN. |
| * |
| * <li>If the argument is positive infinity, then the result is |
| * positive infinity. |
| * |
| * <li>If the argument is negative infinity, then the result is |
| * -1.0. |
| * |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument. |
| * |
| * </ul> |
| * |
| * @param x the exponent to raise <i>e</i> to in the computation of |
| * <i>e</i><sup>{@code x}</sup> -1. |
| * @return the value <i>e</i><sup>{@code x}</sup> - 1. |
| * @since 1.5 |
| */ |
| public static native double expm1(double x); |
| |
| /** |
| * Returns the natural logarithm of the sum of the argument and 1. |
| * Note that for small values {@code x}, the result of |
| * {@code log1p(x)} is much closer to the true result of ln(1 |
| * + {@code x}) than the floating-point evaluation of |
| * {@code log(1.0+x)}. |
| * |
| * <p>Special cases: |
| * <ul> |
| * |
| * <li>If the argument is NaN or less than -1, then the result is |
| * NaN. |
| * |
| * <li>If the argument is positive infinity, then the result is |
| * positive infinity. |
| * |
| * <li>If the argument is negative one, then the result is |
| * negative infinity. |
| * |
| * <li>If the argument is zero, then the result is a zero with the |
| * same sign as the argument. |
| * |
| * </ul> |
| * |
| * @param x a value |
| * @return the value ln({@code x} + 1), the natural |
| * log of {@code x} + 1 |
| * @since 1.5 |
| */ |
| public static native double log1p(double x); |
| |
| /** |
| * 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}. |
| * @since 1.6 |
| */ |
| public static double copySign(double magnitude, double sign) { |
| return Math.copySign(magnitude, (Double.isNaN(sign)?1.0d: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}. |
| * @since 1.6 |
| */ |
| public static float copySign(float magnitude, float sign) { |
| return Math.copySign(magnitude, (Float.isNaN(sign)?1.0f:sign)); |
| } |
| /** |
| * Returns the unbiased exponent used in the representation of a |
| * {@code float}. Special cases: |
| * |
| * <ul> |
| * <li>If the argument is NaN or infinite, then the result is |
| * {@link Float#MAX_EXPONENT} + 1. |
| * <li>If the argument is zero or subnormal, then the result is |
| * {@link Float#MIN_EXPONENT} -1. |
| * </ul> |
| * @param f a {@code float} value |
| * @return the unbiased exponent of the argument |
| * @since 1.6 |
| */ |
| public static int getExponent(float f) { |
| return Math.getExponent(f); |
| } |
| |
| /** |
| * Returns the unbiased exponent used in the representation of a |
| * {@code double}. Special cases: |
| * |
| * <ul> |
| * <li>If the argument is NaN or infinite, then the result is |
| * {@link Double#MAX_EXPONENT} + 1. |
| * <li>If the argument is zero or subnormal, then the result is |
| * {@link Double#MIN_EXPONENT} -1. |
| * </ul> |
| * @param d a {@code double} value |
| * @return the unbiased exponent of the argument |
| * @since 1.6 |
| */ |
| public static int getExponent(double d) { |
| return Math.getExponent(d); |
| } |
| |
| /** |
| * 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 |
| * ±{@link 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, {@link Double#MAX_VALUE} with the |
| * same sign as {@code start} is returned. |
| * |
| * <li> If {@code start} is equal to ± |
| * {@link 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}. |
| * @since 1.6 |
| */ |
| public static double nextAfter(double start, double direction) { |
| return Math.nextAfter(start, direction); |
| } |
| |
| /** |
| * Returns the floating-point number adjacent to the first |
| * argument in the direction of the second argument. If both |
| * arguments compare as equal a value equivalent to 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 value equivalent |
| * to {@code direction} is returned. |
| * |
| * <li> If {@code start} is |
| * ±{@link 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, {@link Float#MAX_VALUE} with the |
| * same sign as {@code start} is returned. |
| * |
| * <li> If {@code start} is equal to ± |
| * {@link 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}. |
| * @since 1.6 |
| */ |
| public static float nextAfter(float start, double direction) { |
| return Math.nextAfter(start, direction); |
| } |
| |
| /** |
| * 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 |
| * {@link Double#MIN_VALUE} |
| * |
| * </ul> |
| * |
| * @param d starting floating-point value |
| * @return The adjacent floating-point value closer to positive |
| * infinity. |
| * @since 1.6 |
| */ |
| 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, |
| * Float.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 |
| * {@link Float#MIN_VALUE} |
| * |
| * </ul> |
| * |
| * @param f starting floating-point value |
| * @return The adjacent floating-point value closer to positive |
| * infinity. |
| * @since 1.6 |
| */ |
| 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. |
| * @since 1.8 |
| */ |
| 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. |
| * @since 1.8 |
| */ |
| public static float nextDown(float f) { |
| return Math.nextDown(f); |
| } |
| |
| /** |
| * Returns {@code d} × |
| * 2<sup>{@code scaleFactor}</sup> rounded as if performed |
| * by a single correctly rounded floating-point multiply to a |
| * member of the double value set. See the Java |
| * Language Specification for a discussion of floating-point |
| * value sets. If the exponent of the result is between {@link |
| * Double#MIN_EXPONENT} and {@link Double#MAX_EXPONENT}, the |
| * answer is calculated exactly. If the exponent of the result |
| * would be larger than {@code Double.MAX_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 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 scaleFactor power of 2 used to scale {@code d} |
| * @return {@code d} × 2<sup>{@code scaleFactor}</sup> |
| * @since 1.6 |
| */ |
| public static double scalb(double d, int scaleFactor) { |
| return Math.scalb(d, scaleFactor); |
| } |
| |
| /** |
| * Returns {@code f} × |
| * 2<sup>{@code scaleFactor}</sup> rounded as if performed |
| * by a single correctly rounded floating-point multiply to a |
| * member of the float value set. See the Java |
| * Language Specification for a discussion of floating-point |
| * value sets. If the exponent of the result is between {@link |
| * Float#MIN_EXPONENT} and {@link Float#MAX_EXPONENT}, the |
| * answer is calculated exactly. If the exponent of the result |
| * would be larger than {@code Float.MAX_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 scaleFactor power of 2 used to scale {@code f} |
| * @return {@code f} × 2<sup>{@code scaleFactor}</sup> |
| * @since 1.6 |
| */ |
| public static float scalb(float f, int scaleFactor) { |
| return Math.scalb(f, scaleFactor); |
| } |
| } |
