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jeremybenn |
/* VMMath.java -- Common mathematical functions.
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Copyright (C) 2006 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.lang;
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import gnu.classpath.Configuration;
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class VMMath
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{
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static
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{
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if (Configuration.INIT_LOAD_LIBRARY)
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{
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System.loadLibrary("javalang");
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}
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}
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/**
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* The trigonometric function <em>sin</em>. The sine of NaN or infinity is
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* NaN, and the sine of 0 retains its sign. This is accurate within 1 ulp,
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* and is semi-monotonic.
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*
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* @param a the angle (in radians)
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* @return sin(a)
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*/
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public static native double sin(double a);
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/**
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* The trigonometric function <em>cos</em>. The cosine of NaN or infinity is
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* NaN. This is accurate within 1 ulp, and is semi-monotonic.
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*
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* @param a the angle (in radians)
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* @return cos(a)
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*/
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public static native double cos(double a);
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/**
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* The trigonometric function <em>tan</em>. The tangent of NaN or infinity
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* is NaN, and the tangent of 0 retains its sign. This is accurate within 1
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* ulp, and is semi-monotonic.
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*
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* @param a the angle (in radians)
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* @return tan(a)
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*/
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public static native double tan(double a);
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/**
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* The trigonometric function <em>arcsin</em>. The range of angles returned
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* is -pi/2 to pi/2 radians (-90 to 90 degrees). If the argument is NaN or
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* its absolute value is beyond 1, the result is NaN; and the arcsine of
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* 0 retains its sign. This is accurate within 1 ulp, and is semi-monotonic.
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*
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* @param a the sin to turn back into an angle
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* @return arcsin(a)
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*/
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public static native double asin(double a);
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/**
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* The trigonometric function <em>arccos</em>. The range of angles returned
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* is 0 to pi radians (0 to 180 degrees). If the argument is NaN or
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* its absolute value is beyond 1, the result is NaN. This is accurate
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* within 1 ulp, and is semi-monotonic.
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*
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* @param a the cos to turn back into an angle
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* @return arccos(a)
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*/
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public static native double acos(double a);
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/**
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* The trigonometric function <em>arcsin</em>. The range of angles returned
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* is -pi/2 to pi/2 radians (-90 to 90 degrees). If the argument is NaN, the
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* result is NaN; and the arctangent of 0 retains its sign. This is accurate
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* within 1 ulp, and is semi-monotonic.
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*
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* @param a the tan to turn back into an angle
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* @return arcsin(a)
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* @see #atan2(double, double)
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*/
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public static native double atan(double a);
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/**
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* A special version of the trigonometric function <em>arctan</em>, for
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* converting rectangular coordinates <em>(x, y)</em> to polar
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* <em>(r, theta)</em>. This computes the arctangent of x/y in the range
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* of -pi to pi radians (-180 to 180 degrees). Special cases:<ul>
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* <li>If either argument is NaN, the result is NaN.</li>
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* <li>If the first argument is positive zero and the second argument is
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* positive, or the first argument is positive and finite and the second
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* argument is positive infinity, then the result is positive zero.</li>
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* <li>If the first argument is negative zero and the second argument is
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* positive, or the first argument is negative and finite and the second
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* argument is positive infinity, then the result is negative zero.</li>
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* <li>If the first argument is positive zero and the second argument is
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* negative, or the first argument is positive and finite and the second
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* argument is negative infinity, then the result is the double value
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* closest to pi.</li>
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* <li>If the first argument is negative zero and the second argument is
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* negative, or the first argument is negative and finite and the second
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* argument is negative infinity, then the result is the double value
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* closest to -pi.</li>
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* <li>If the first argument is positive and the second argument is
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* positive zero or negative zero, or the first argument is positive
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* infinity and the second argument is finite, then the result is the
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* double value closest to pi/2.</li>
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* <li>If the first argument is negative and the second argument is
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* positive zero or negative zero, or the first argument is negative
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* infinity and the second argument is finite, then the result is the
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* double value closest to -pi/2.</li>
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* <li>If both arguments are positive infinity, then the result is the
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* double value closest to pi/4.</li>
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* <li>If the first argument is positive infinity and the second argument
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* is negative infinity, then the result is the double value closest to
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* 3*pi/4.</li>
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* <li>If the first argument is negative infinity and the second argument
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* is positive infinity, then the result is the double value closest to
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* -pi/4.</li>
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* <li>If both arguments are negative infinity, then the result is the
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* double value closest to -3*pi/4.</li>
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*
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* </ul><p>This is accurate within 2 ulps, and is semi-monotonic. To get r,
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* use sqrt(x*x+y*y).
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*
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* @param y the y position
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* @param x the x position
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* @return <em>theta</em> in the conversion of (x, y) to (r, theta)
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* @see #atan(double)
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*/
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public static native double atan2(double y, double x);
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/**
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* Take <em>e</em><sup>a</sup>. The opposite of <code>log()</code>. If the
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* argument is NaN, the result is NaN; if the argument is positive infinity,
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* the result is positive infinity; and if the argument is negative
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* infinity, the result is positive zero. This is accurate within 1 ulp,
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* and is semi-monotonic.
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*
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* @param a the number to raise to the power
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* @return the number raised to the power of <em>e</em>
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* @see #log(double)
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* @see #pow(double, double)
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*/
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public static native double exp(double a);
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/**
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* Take ln(a) (the natural log). The opposite of <code>exp()</code>. If the
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* argument is NaN or negative, the result is NaN; if the argument is
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* positive infinity, the result is positive infinity; and if the argument
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* is either zero, the result is negative infinity. This is accurate within
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* 1 ulp, and is semi-monotonic.
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*
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* <p>Note that the way to get log<sub>b</sub>(a) is to do this:
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* <code>ln(a) / ln(b)</code>.
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*
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* @param a the number to take the natural log of
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* @return the natural log of <code>a</code>
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* @see #exp(double)
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*/
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public static native double log(double a);
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/**
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* Take a square root. If the argument is NaN or negative, the result is
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* NaN; if the argument is positive infinity, the result is positive
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* infinity; and if the result is either zero, the result is the same.
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* This is accurate within the limits of doubles.
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*
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* <p>For other roots, use pow(a, 1 / rootNumber).
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*
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* @param a the numeric argument
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* @return the square root of the argument
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* @see #pow(double, double)
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*/
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public static native double sqrt(double a);
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/**
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* Raise a number to a power. Special cases:<ul>
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* <li>If the second argument is positive or negative zero, then the result
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* is 1.0.</li>
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* <li>If the second argument is 1.0, then the result is the same as the
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* first argument.</li>
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* <li>If the second argument is NaN, then the result is NaN.</li>
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* <li>If the first argument is NaN and the second argument is nonzero,
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* then the result is NaN.</li>
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* <li>If the absolute value of the first argument is greater than 1 and
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* the second argument is positive infinity, or the absolute value of the
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* first argument is less than 1 and the second argument is negative
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* infinity, then the result is positive infinity.</li>
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* <li>If the absolute value of the first argument is greater than 1 and
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* the second argument is negative infinity, or the absolute value of the
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* first argument is less than 1 and the second argument is positive
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* infinity, then the result is positive zero.</li>
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* <li>If the absolute value of the first argument equals 1 and the second
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* argument is infinite, then the result is NaN.</li>
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* <li>If the first argument is positive zero and the second argument is
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* greater than zero, or the first argument is positive infinity and the
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* second argument is less than zero, then the result is positive zero.</li>
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* <li>If the first argument is positive zero and the second argument is
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* less than zero, or the first argument is positive infinity and the
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* second argument is greater than zero, then the result is positive
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* infinity.</li>
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* <li>If the first argument is negative zero and the second argument is
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* greater than zero but not a finite odd integer, or the first argument is
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* negative infinity and the second argument is less than zero but not a
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* finite odd integer, then the result is positive zero.</li>
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* <li>If the first argument is negative zero and the second argument is a
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* positive finite odd integer, or the first argument is negative infinity
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* and the second argument is a negative finite odd integer, then the result
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* is negative zero.</li>
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* <li>If the first argument is negative zero and the second argument is
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* less than zero but not a finite odd integer, or the first argument is
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* negative infinity and the second argument is greater than zero but not a
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* finite odd integer, then the result is positive infinity.</li>
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* <li>If the first argument is negative zero and the second argument is a
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* negative finite odd integer, or the first argument is negative infinity
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* and the second argument is a positive finite odd integer, then the result
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* is negative infinity.</li>
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* <li>If the first argument is less than zero and the second argument is a
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* finite even integer, then the result is equal to the result of raising
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* the absolute value of the first argument to the power of the second
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* argument.</li>
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* <li>If the first argument is less than zero and the second argument is a
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* finite odd integer, then the result is equal to the negative of the
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* result of raising the absolute value of the first argument to the power
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* of the second argument.</li>
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* <li>If the first argument is finite and less than zero and the second
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* argument is finite and not an integer, then the result is NaN.</li>
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* <li>If both arguments are integers, then the result is exactly equal to
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* the mathematical result of raising the first argument to the power of
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* the second argument if that result can in fact be represented exactly as
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* a double value.</li>
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*
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* </ul><p>(In the foregoing descriptions, a floating-point value is
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* considered to be an integer if and only if it is a fixed point of the
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* method {@link #ceil(double)} or, equivalently, a fixed point of the
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* method {@link #floor(double)}. A value is a fixed point of a one-argument
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* method if and only if the result of applying the method to the value is
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* equal to the value.) This is accurate within 1 ulp, and is semi-monotonic.
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*
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* @param a the number to raise
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* @param b the power to raise it to
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* @return a<sup>b</sup>
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*/
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public static native double pow(double a, double b);
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/**
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* Get the IEEE 754 floating point remainder on two numbers. This is the
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* value of <code>x - y * <em>n</em></code>, where <em>n</em> is the closest
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* double to <code>x / y</code> (ties go to the even n); for a zero
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* remainder, the sign is that of <code>x</code>. If either argument is NaN,
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* the first argument is infinite, or the second argument is zero, the result
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* is NaN; if x is finite but y is infinite, the result is x. This is
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* accurate within the limits of doubles.
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*
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* @param x the dividend (the top half)
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* @param y the divisor (the bottom half)
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* @return the IEEE 754-defined floating point remainder of x/y
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* @see #rint(double)
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*/
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public static native double IEEEremainder(double x, double y);
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/**
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* Take the nearest integer that is that is greater than or equal to the
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* argument. If the argument is NaN, infinite, or zero, the result is the
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* same; if the argument is between -1 and 0, the result is negative zero.
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* Note that <code>Math.ceil(x) == -Math.floor(-x)</code>.
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*
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* @param a the value to act upon
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* @return the nearest integer >= <code>a</code>
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*/
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public static native double ceil(double a);
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/**
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* Take the nearest integer that is that is less than or equal to the
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* argument. If the argument is NaN, infinite, or zero, the result is the
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* same. Note that <code>Math.ceil(x) == -Math.floor(-x)</code>.
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*
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* @param a the value to act upon
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* @return the nearest integer <= <code>a</code>
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*/
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public static native double floor(double a);
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/**
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* Take the nearest integer to the argument. If it is exactly between
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* two integers, the even integer is taken. If the argument is NaN,
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* infinite, or zero, the result is the same.
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*
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* @param a the value to act upon
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* @return the nearest integer to <code>a</code>
|
324 |
|
|
*/
|
325 |
|
|
public static native double rint(double a);
|
326 |
|
|
|
327 |
|
|
/**
|
328 |
|
|
* <p>
|
329 |
|
|
* Take a cube root. If the argument is NaN, an infinity or zero, then
|
330 |
|
|
* the original value is returned. The returned result must be within 1 ulp
|
331 |
|
|
* of the exact result. For a finite value, <code>x</code>, the cube root
|
332 |
|
|
* of <code>-x</code> is equal to the negation of the cube root
|
333 |
|
|
* of <code>x</code>.
|
334 |
|
|
* </p>
|
335 |
|
|
* <p>
|
336 |
|
|
* For a square root, use <code>sqrt</code>. For other roots, use
|
337 |
|
|
* <code>pow(a, 1 / rootNumber)</code>.
|
338 |
|
|
* </p>
|
339 |
|
|
*
|
340 |
|
|
* @param a the numeric argument
|
341 |
|
|
* @return the cube root of the argument
|
342 |
|
|
* @see #sqrt(double)
|
343 |
|
|
* @see #pow(double, double)
|
344 |
|
|
*/
|
345 |
|
|
public static native double cbrt(double a);
|
346 |
|
|
|
347 |
|
|
/**
|
348 |
|
|
* <p>
|
349 |
|
|
* Returns the hyperbolic cosine of the given value. For a value,
|
350 |
|
|
* <code>x</code>, the hyperbolic cosine is <code>(e<sup>x</sup> +
|
351 |
|
|
* e<sup>-x</sup>)/2</code>
|
352 |
|
|
* with <code>e</code> being <a href="#E">Euler's number</a>. The returned
|
353 |
|
|
* result must be within 2.5 ulps of the exact result.
|
354 |
|
|
* </p>
|
355 |
|
|
* <p>
|
356 |
|
|
* If the supplied value is <code>NaN</code>, then the original value is
|
357 |
|
|
* returned. For either infinity, positive infinity is returned.
|
358 |
|
|
* The hyperbolic cosine of zero must be 1.0.
|
359 |
|
|
* </p>
|
360 |
|
|
*
|
361 |
|
|
* @param a the numeric argument
|
362 |
|
|
* @return the hyperbolic cosine of <code>a</code>.
|
363 |
|
|
* @since 1.5
|
364 |
|
|
*/
|
365 |
|
|
public static native double cosh(double a);
|
366 |
|
|
|
367 |
|
|
/**
|
368 |
|
|
* <p>
|
369 |
|
|
* Returns <code>e<sup>a</sup> - 1. For values close to 0, the
|
370 |
|
|
* result of <code>expm1(a) + 1</code> tend to be much closer to the
|
371 |
|
|
* exact result than simply <code>exp(x)</code>. The result must be within
|
372 |
|
|
* 1 ulp of the exact result, and results must be semi-monotonic. For finite
|
373 |
|
|
* inputs, the returned value must be greater than or equal to -1.0. Once
|
374 |
|
|
* a result enters within half a ulp of this limit, the limit is returned.
|
375 |
|
|
* </p>
|
376 |
|
|
* <p>
|
377 |
|
|
* For <code>NaN</code>, positive infinity and zero, the original value
|
378 |
|
|
* is returned. Negative infinity returns a result of -1.0 (the limit).
|
379 |
|
|
* </p>
|
380 |
|
|
*
|
381 |
|
|
* @param a the numeric argument
|
382 |
|
|
* @return <code>e<sup>a</sup> - 1</code>
|
383 |
|
|
* @since 1.5
|
384 |
|
|
*/
|
385 |
|
|
public static native double expm1(double a);
|
386 |
|
|
|
387 |
|
|
/**
|
388 |
|
|
* <p>
|
389 |
|
|
* Returns the hypotenuse, <code>a<sup>2</sup> + b<sup>2</sup></code>,
|
390 |
|
|
* without intermediate overflow or underflow. The returned result must be
|
391 |
|
|
* within 1 ulp of the exact result. If one parameter is held constant,
|
392 |
|
|
* then the result in the other parameter must be semi-monotonic.
|
393 |
|
|
* </p>
|
394 |
|
|
* <p>
|
395 |
|
|
* If either of the arguments is an infinity, then the returned result
|
396 |
|
|
* is positive infinity. Otherwise, if either argument is <code>NaN</code>,
|
397 |
|
|
* then <code>NaN</code> is returned.
|
398 |
|
|
* </p>
|
399 |
|
|
*
|
400 |
|
|
* @param a the first parameter.
|
401 |
|
|
* @param b the second parameter.
|
402 |
|
|
* @return the hypotenuse matching the supplied parameters.
|
403 |
|
|
* @since 1.5
|
404 |
|
|
*/
|
405 |
|
|
public static native double hypot(double a, double b);
|
406 |
|
|
|
407 |
|
|
/**
|
408 |
|
|
* <p>
|
409 |
|
|
* Returns the base 10 logarithm of the supplied value. The returned
|
410 |
|
|
* result must within 1 ulp of the exact result, and the results must be
|
411 |
|
|
* semi-monotonic.
|
412 |
|
|
* </p>
|
413 |
|
|
* <p>
|
414 |
|
|
* Arguments of either <code>NaN</code> or less than zero return
|
415 |
|
|
* <code>NaN</code>. An argument of positive infinity returns positive
|
416 |
|
|
* infinity. Negative infinity is returned if either positive or negative
|
417 |
|
|
* zero is supplied. Where the argument is the result of
|
418 |
|
|
* <code>10<sup>n</sup</code>, then <code>n</code> is returned.
|
419 |
|
|
* </p>
|
420 |
|
|
*
|
421 |
|
|
* @param a the numeric argument.
|
422 |
|
|
* @return the base 10 logarithm of <code>a</code>.
|
423 |
|
|
* @since 1.5
|
424 |
|
|
*/
|
425 |
|
|
public static native double log10(double a);
|
426 |
|
|
|
427 |
|
|
/**
|
428 |
|
|
* <p>
|
429 |
|
|
* Returns the natural logarithm resulting from the sum of the argument,
|
430 |
|
|
* <code>a</code> and 1. For values close to 0, the
|
431 |
|
|
* result of <code>log1p(a)</code> tend to be much closer to the
|
432 |
|
|
* exact result than simply <code>log(1.0+a)</code>. The returned
|
433 |
|
|
* result must be within 1 ulp of the exact result, and the results must be
|
434 |
|
|
* semi-monotonic.
|
435 |
|
|
* </p>
|
436 |
|
|
* <p>
|
437 |
|
|
* Arguments of either <code>NaN</code> or less than -1 return
|
438 |
|
|
* <code>NaN</code>. An argument of positive infinity or zero
|
439 |
|
|
* returns the original argument. Negative infinity is returned from an
|
440 |
|
|
* argument of -1.
|
441 |
|
|
* </p>
|
442 |
|
|
*
|
443 |
|
|
* @param a the numeric argument.
|
444 |
|
|
* @return the natural logarithm of <code>a</code> + 1.
|
445 |
|
|
* @since 1.5
|
446 |
|
|
*/
|
447 |
|
|
public static native double log1p(double a);
|
448 |
|
|
|
449 |
|
|
/**
|
450 |
|
|
* <p>
|
451 |
|
|
* Returns the hyperbolic sine of the given value. For a value,
|
452 |
|
|
* <code>x</code>, the hyperbolic sine is <code>(e<sup>x</sup> -
|
453 |
|
|
* e<sup>-x</sup>)/2</code>
|
454 |
|
|
* with <code>e</code> being <a href="#E">Euler's number</a>. The returned
|
455 |
|
|
* result must be within 2.5 ulps of the exact result.
|
456 |
|
|
* </p>
|
457 |
|
|
* <p>
|
458 |
|
|
* If the supplied value is <code>NaN</code>, an infinity or a zero, then the
|
459 |
|
|
* original value is returned.
|
460 |
|
|
* </p>
|
461 |
|
|
*
|
462 |
|
|
* @param a the numeric argument
|
463 |
|
|
* @return the hyperbolic sine of <code>a</code>.
|
464 |
|
|
* @since 1.5
|
465 |
|
|
*/
|
466 |
|
|
public static native double sinh(double a);
|
467 |
|
|
|
468 |
|
|
/**
|
469 |
|
|
* <p>
|
470 |
|
|
* Returns the hyperbolic tangent of the given value. For a value,
|
471 |
|
|
* <code>x</code>, the hyperbolic tangent is <code>(e<sup>x</sup> -
|
472 |
|
|
* e<sup>-x</sup>)/(e<sup>x</sup> + e<sup>-x</sup>)</code>
|
473 |
|
|
* (i.e. <code>sinh(a)/cosh(a)</code>)
|
474 |
|
|
* with <code>e</code> being <a href="#E">Euler's number</a>. The returned
|
475 |
|
|
* result must be within 2.5 ulps of the exact result. The absolute value
|
476 |
|
|
* of the exact result is always less than 1. Computed results are thus
|
477 |
|
|
* less than or equal to 1 for finite arguments, with results within
|
478 |
|
|
* half a ulp of either positive or negative 1 returning the appropriate
|
479 |
|
|
* limit value (i.e. as if the argument was an infinity).
|
480 |
|
|
* </p>
|
481 |
|
|
* <p>
|
482 |
|
|
* If the supplied value is <code>NaN</code> or zero, then the original
|
483 |
|
|
* value is returned. Positive infinity returns +1.0 and negative infinity
|
484 |
|
|
* returns -1.0.
|
485 |
|
|
* </p>
|
486 |
|
|
*
|
487 |
|
|
* @param a the numeric argument
|
488 |
|
|
* @return the hyperbolic tangent of <code>a</code>.
|
489 |
|
|
* @since 1.5
|
490 |
|
|
*/
|
491 |
|
|
public static native double tanh(double a);
|
492 |
|
|
|
493 |
|
|
}
|