IEEE (JMSL Numerical Library)

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JMSL^TM Numerical Library 4.0

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com.imsl.math
Class IEEE

java.lang.Object
  com.imsl.math.IEEE

public class IEEE
extends Object

Pure Java implementation of the IEEE 754 functions as specified in IEEE Standard for Binary Floating-Point Arithmetic, ANSI/IEEE Standard 754-1985 (IEEE, New York).

This Java code is based on C code in the package fdlibm, which can be obtained from www.netlib.org. The original fdlibm C code contains the following notice.

Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
Developed at SunSoft, a Sun Microsystems, Inc. business. Permission to use, copy, modify, and distribute this software is freely granted, provided that this notice is preserved.

Method Summary
`static double`	`copysign(double x, double y)` Returns a value with the magnitude of x and with the sign bit of y.
`static boolean`	`finite(double x)` Finite number test on an argument of type double.
`static int`	`ilogb(double x)` Return the binary exponent of non-zero x.
`static boolean`	`isNaN(double x)` NaN test on an argument of type double.
`static double`	`nextAfter(double x, double y)` Returns the next machine floating-point number next to x in the direction toward y.
`static double`	`scalbn(double x, int n)` Returns 2ⁿ computed by exponent manipulation rather than by actually performing an exponentiation or a multiplication.
`static boolean`	`unordered(double x, double y)` Unordered test on a pair of `double`s.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

copysign

public static double copysign(double x,
                              double y)

Returns a value with the magnitude of x and with the sign bit of y. If y is NaN then |x| is returned.

Parameters:: x - a double from which the magnitude will be gleaned; y - a double from which the sign will be gleaned
Returns:: a double value with magnitude x and sign of y

finite

public static boolean finite(double x)

Finite number test on an argument of type double.

Parameters:: x - the double which is to be tested
Returns:: true if x is a finite number, false if x is a NaN or an infinity

ilogb

public static int ilogb(double x)

Return the binary exponent of non-zero x.

Parameters:: x - a double
Returns:: an int representing the binary exponent of x. Special cases ilogb(0) = -Integer.MAX_VALUE and ${rm {ilogb}} (infty) = {rm {ilogb}} (-infty) = {rm {ilogb}} (NaN) = {rm {Integer.MAX_VALUE}}$ .
See Also:: Integer.MAX_VALUE

isNaN

public static boolean isNaN(double x)

NaN test on an argument of type double.

Parameters:: x - the double which is to be tested
Returns:: true if x is a NaN, false otherwise

nextAfter

public static double nextAfter(double x,
                               double y)

Returns the next machine floating-point number next to x in the direction toward y.

Parameters:: x - a double; y - a double
Returns:: a double which represents the value which is closest to x in the interval bounded by x and y

scalbn

public static double scalbn(double x,
                            int n)

Returns 2ⁿ computed by exponent manipulation rather than by actually performing an exponentiation or a multiplication.

Parameters:: x - a double; n - an int representing the power to which 2 is raised
Returns:: a double representing .

unordered

public static boolean unordered(double x,
                                double y)

Unordered test on a pair of doubles. Tests whether either of a pair of doubles is a NaN.

Parameters:: x - a double; y - a double
Returns:: true if either x or y is a NaN, false otherwise