com.codename1.util

Class MathUtil

java.lang.Object

com.codename1.util.MathUtil

public abstract class MathUtil
extends Object

MathUtil for Java ME. This fills the gap in Java ME Math with a port of Sun's public FDLIBM C-library for IEEE-754.

Author:

kmashint

See Also:

For the Freely Distributable C-library conforming to IEEE-754 floating point math., For the GNU C variant of the same IEEE-754 routines., Another take on the IEEE-754 routines., Yet another take on the IEEE-754 routines., For other approximations., For fast but rough approximations., For more fast but rough approximations.

Constructor Summary

Constructors

Constructor and Description
MathUtil()

Method Summary

Modifier and Type	Method and Description
static double	acos(double a) Return the arccosine of a.
static double	asin(double a) Return the arcsine of a.
static double	atan(double a) Return the arctangent of a, call it b, where a = tan(b).
static double	atan2(double b, double a) For any real arguments x and y not both equal to zero, atan2(y, x) is the angle in radians between the positive x-axis of a plane and the point given by the coordinates (x, y) on it.
static double	copysign(double x, double y) Deprecated. Please update your code to use copySign
static double	copySign(double x, double y)
static double	exp(double a) Return Math.E to the exponent a.
static long	floor(double a) Rounds the number down
static int	floor(float a) Rounds the number down
static double	log(double a) Return the natural logarithm, ln(a), as it relates to Math.E.
static double	log10(double a) Return the common base-10 logarithm, log10(a).
static double	nextAfter(double start, double direction) Returns the next representable floating point number after the first argument in the direction of the second argument.
static double	pow(double a, double b) Return a to the power of b, sometimes written as a ** b but not to be confused with the bitwise ^ operator.
static long	round(double a) Rounds the number to the closest integer
static int	round(float a) Rounds the number to the closest integer
static double	scalb(double x, int n) scalbn (double x, int n) scalbn(x,n) returns x* 2**n computed by exponent manipulation rather than by actually performing an exponentiation or a multiplication.
static double	scalbn(double x, int n) Deprecated. Please update your code to use scalb
static double	ulp(double d) Returns the size of an ulp (units in the last place) of the argument.

Methods inherited from class java.lang.Object

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

Constructor Detail

MathUtil

public MathUtil()

Method Detail

exp

public static final double exp(double a)

Return Math.E to the exponent a. This in turn uses ieee7854_exp(double).

log

public static final double log(double a)

Return the natural logarithm, ln(a), as it relates to Math.E. This in turn uses ieee7854_log(double).

log10

public static final double log10(double a)

Return the common base-10 logarithm, log10(a). This in turn uses ieee7854_log(double)/ieee7854_log(10.0).

pow

public static final double pow(double a,
                               double b)

Return a to the power of b, sometimes written as a ** b but not to be confused with the bitwise ^ operator. This in turn uses ieee7854_log(double).

asin

public static final double asin(double a)

Return the arcsine of a.

acos

public static final double acos(double a)

Return the arccosine of a.

atan

public static final double atan(double a)

Return the arctangent of a, call it b, where a = tan(b).

atan2

public static final double atan2(double b,
                                 double a)

For any real arguments x and y not both equal to zero, atan2(y, x) is the angle in radians between the positive x-axis of a plane and the point given by the coordinates (x, y) on it. The angle is positive for counter-clockwise angles (upper half-plane, y > 0), and negative for clockwise angles (lower half-plane, y < 0). This in turn uses ieee7854_arctan2(double).

scalb

public static final double scalb(double x,
                                 int n)

scalbn (double x, int n) scalbn(x,n) returns x* 2**n computed by exponent manipulation rather than by actually performing an exponentiation or a multiplication.

scalbn

public static final double scalbn(double x,
                                  int n)

Deprecated. Please update your code to use scalb

Please update your code to use scalb

Parameters:

x -

n -

Returns:

scalb(x,n)

copySign

public static final double copySign(double x,
                                    double y)

copysign

public static final double copysign(double x,
                                    double y)

Deprecated. Please update your code to use copySign

Please update your code to use copySign

Parameters:

x -

y -

Returns:

copySign(x,y)

ulp

public static double ulp(double d)

Returns the size of an ulp (units in the last place) of the argument.

Parameters:

d - value whose ulp is to be returned

Returns:

size of an ulp for the argument

nextAfter

public static double nextAfter(double start,
                               double direction)

Returns the next representable floating point number after the first argument in the direction of the second argument.

Parameters:

start - starting value

direction - value indicating which of the neighboring representable floating point number to return

Returns:

The floating-point number next to start in the direction of .

round

public static int round(float a)

Rounds the number to the closest integer

Parameters:

a - the number

Returns:

the closest integer

round

public static long round(double a)

Rounds the number to the closest integer

Parameters:

a - the number

Returns:

the closest integer

floor

public static int floor(float a)

Rounds the number down

Parameters:

a - the number

Returns:

a rounded down number

floor

public static long floor(double a)

Rounds the number down

Parameters:

a - the number

Returns:

a rounded down number