java.lang
Class Math

java.lang.Object
  |
  +--java.lang.Math

public final class Math

extends Object

Helper class containing useful mathematical functions and constants.

Note that angles are specified in radians. Conversion functions are provided for your convenience.

Field Summary

static double	E The mathematical constant e.
static double	NaN
static double	NEGATIVE_INFINITY
static double	PI The mathematical constant pi.
static double	POSITIVE_INFINITY

Constructor Summary

Math()

Method Summary

static double	abs(double a) Take the absolute value of the argument.
static int	abs(int a) Take the absolute value of the argument.
static long	abs(long a) Take the absolute value of the argument.
static double	acos(double x) The trigonometric function arccos.
static double	asin(double x) The trigonometric function arcsin.
static double	atan(double x) The trigonometric function arctan.
static double	atan2(double y, double x) A special version of the trigonometric function arctan.
static double	ceil(double x) Take the nearest integer that is that is greater than or equal to the argument.
static double	cos(double x) The trigonometric function cos.
static double	exp(double x) Take ex.
static double	floor(double x) Take the nearest integer that is that is less than or equal to the argument.
static double	IEEEremainder(double x, double y) Get the floating point remainder on two numbers, which really does the following: Takes x/y and finds the nearest integer n to the quotient.
static boolean	isNaN(double d)
static double	log(double x) Take ln(x) (the natural log).
static double	max(double a, double b) Return whichever argument is larger.
static int	max(int a, int b) Return whichever argument is larger.
static long	max(long a, long b) Return whichever argument is larger.
static double	min(double a, double b) Return whichever argument is smaller.
static int	min(int a, int b) Return whichever argument is smaller.
static long	min(long a, long b) Return whichever argument is smaller.
static double	pow(double x, double y) Take a number to a power.
static double	rint(double x) Take the nearest integer to the argument.
static long	round(double a) Take the nearest integer to the argument.
static double	sin(double x) The trigonometric function sin.
static double	sqrt(double x) Take a square root.
static double	tan(double x) The trigonometric function tan.
static double	toDegrees(double rads) Convert from radians to degrees.
static double	toRadians(double degrees) Convert from degrees to radians.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, toString, wait, wait

Field Detail

NaN

public static final double NaN

POSITIVE_INFINITY

public static final double POSITIVE_INFINITY

NEGATIVE_INFINITY

public static final double NEGATIVE_INFINITY

E

public static final double E

The mathematical constant e. Used in natural log and exp.

See Also:

log(double), exp(double)

PI

public static final double PI

The mathematical constant pi. This is the ratio of a circle's diameter to its circumference.

Constructor Detail

Math

public Math()

Method Detail

abs

public static int abs(int a)

Take the absolute value of the argument. (Absolute value means make it positive.)

Note that the largest negative value (Integer.MIN_VALUE) cannot be made positive. In this case, because of the rules of negation in a computer, MIN_VALUE is what will be returned. This is a negative value. You have been warned.

Parameters:

a - the number to take the absolute value of.

Returns:

the absolute value.

abs

public static long abs(long a)

Take the absolute value of the argument. (Absolute value means make it positive.)

Note that the largest negative value (Long.MIN_VALUE) cannot be made positive. In this case, because of the rules of negation in a computer, MIN_VALUE is what will be returned. This is a negative value. You have been warned.

Parameters:

a - the number to take the absolute value of.

Returns:

the absolute value.

abs

public static double abs(double a)

Take the absolute value of the argument. (Absolute value means make it positive.)

Parameters:

a - the number to take the absolute value of.

Returns:

the absolute value.

min

public static int min(int a,
                      int b)

Return whichever argument is smaller.

Parameters:

a - the first number

b - a second number

Returns:

the smaller of the two numbers.

min

public static long min(long a,
                       long b)

Return whichever argument is smaller.

Parameters:

a - the first number

b - a second number

Returns:

the smaller of the two numbers.

min

public static double min(double a,
                         double b)

Return whichever argument is smaller.

Parameters:

a - the first number

b - a second number

Returns:

the smaller of the two numbers.

max

public static int max(int a,
                      int b)

Return whichever argument is larger.

Parameters:

a - the first number

b - a second number

Returns:

the larger of the two numbers.

max

public static long max(long a,
                       long b)

Return whichever argument is larger.

Parameters:

a - the first number

b - a second number

Returns:

the larger of the two numbers.

max

public static double max(double a,
                         double b)

Return whichever argument is larger.

Parameters:

a - the first number

b - a second number

Returns:

the larger of the two numbers.

sin

public static double sin(double x)

The trigonometric function sin.

Parameters:

x - the angle (in radians).

Returns:

sin(x).

cos

public static double cos(double x)

The trigonometric function cos.

Parameters:

x - the angle (in radians).

Returns:

cos(x).

tan

public static double tan(double x)

The trigonometric function tan.

Parameters:

x - the angle (in radians).

Returns:

tan(x).

asin

public static double asin(double x)

The trigonometric function arcsin. The range of angles you will get are from -pi/2 to pi/2 radians (-90 to 90 degrees)

Parameters:

x - the sin to turn back into an angle.

Returns:

arcsin(x).

acos

public static double acos(double x)

The trigonometric function arccos. The range of angles you will get are from 0 to pi radians (0 to 180 degrees).

Parameters:

x - the cos to turn back into an angle.

Returns:

arccos(x).

atan

public static double atan(double x)

The trigonometric function arctan. The range of angles you will get are from -pi/2 to pi/2 radians (-90 to 90 degrees)

Parameters:

x - the tan to turn back into an angle.

Returns:

arctan(x).

See Also:

atan2(double,double)

atan2

public static double atan2(double y,
                           double x)

A special version of the trigonometric function arctan. Given a position (x,y), this function will give you the angle of that position. The range of angles you will get are from -pi to pi radians (-180 to 180 degrees), the whole spectrum of angles. That is what makes this function so much more useful than the other atan().

Parameters:

y - the y position

x - the x position

Returns:

arctan(y/x).

See Also:

atan(double)

exp

public static double exp(double x)

Take e^x. The opposite of log().

Parameters:

x - the number to raise to the power.

Returns:

the number raised to the power of e.

See Also:

log(double), pow(double,double)

log

public static double log(double x)

Take ln(x) (the natural log). The opposite of exp(). Note that the way to get log_b(a) is to do this: ln(a) / ln(b).

Parameters:

x - the number to take the natural log of.

Returns:

the natural log of x.

See Also:

exp(double)

sqrt

public static double sqrt(double x)

Take a square root. For other roots, to pow(x,1/rootNumber).

Parameters:

x - the numeric argument

Returns:

the square root of the argument.

See Also:

pow(double,double)

pow

public static double pow(double x,
                         double y)

Take a number to a power.

Parameters:

x - the number to raise.

y - the power to raise it to.

Returns:

x^y.

IEEEremainder

public static double IEEEremainder(double x,
                                   double y)

Get the floating point remainder on two numbers, which really does the following:

1. Takes x/y and finds the nearest integer n to the quotient. (Uses the rint() function to do this.
2. Takes x - y*n.
3. If x = y*n, then the result is 0 if x is positive and -0 if x is negative.

Parameters:

x - the dividend (the top half)

y - the divisor (the bottom half)

Returns:

the IEEE 754-defined floating point remainder of x/y.

See Also:

rint(double)

ceil

public static double ceil(double x)

Take the nearest integer that is that is greater than or equal to the argument.

Parameters:

x - the value to act upon.

Returns:

the nearest integer >= x.

floor

public static double floor(double x)

Take the nearest integer that is that is less than or equal to the argument.

Parameters:

x - the value to act upon.

Returns:

the nearest integer <= x.

rint

public static double rint(double x)

Take the nearest integer to the argument. If it is exactly between two integers, the even integer is taken.

Parameters:

x - the value to act upon.

Returns:

the nearest integer to x.

round

public static long round(double a)

Take the nearest integer to the argument. If it is exactly between two integers, then the lower of the two (-10 lower than -9) is taken. If the argument is less than Long.MIN_VALUE or negative infinity, Long.MIN_VALUE will be returned. If the argument is greater than Long.MAX_VALUE, Long.MAX_VALUE will be returned.

Parameters:

a - the argument to round.

Returns:

the nearest integer to the argument.

toRadians

public static double toRadians(double degrees)

Convert from degrees to radians. The formula for this is radians = degrees * (pi/180).

Parameters:

degrees - an angle in degrees

Returns:

the angle in radians

toDegrees

public static double toDegrees(double rads)

Convert from radians to degrees. The formula for this is degrees = radians * (180/pi).

Parameters:

rads - an angle in radians

Returns:

the angle in degrees

isNaN

public static boolean isNaN(double d)