org.encog.mathutil

Class EncogMath

java.lang.Object

org.encog.mathutil.EncogMath

public final class EncogMath
extends java.lang.Object

Several useful math functions for Encog.

Method Summary

Modifier and Type	Method and Description
static double	deg2rad(double deg) Convert degrees to radians.
static boolean	doubleEquals(double d1, double d2) Determine if one double equals another, within the default percision.
static double	factorial(int x) Calculate x!.
static double	hypot(double a, double b) sqrt(a^2 + b^2) without under/overflow.
static int	maxIndex(double[] array) Get the index to the greatest number in a double array.
static int	minIndex(double[] array) Get the index to the smallest number in a double array.
static double	rad2deg(double rad) Convert radians to degrees.
static int	sign(double value) Determine the sign of the value.
static double	square(double d)
static int	thirds(double value) Transform a number in the range (-1,1) to a tri-state value indicated by -1, 0 or 1.

Methods inherited from class java.lang.Object

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

Method Detail

deg2rad

public static double deg2rad(double deg)

Convert degrees to radians.

Parameters:

deg - Degrees.

Returns:

Radians.

doubleEquals

public static boolean doubleEquals(double d1,
                                   double d2)

Determine if one double equals another, within the default percision.

Parameters:

d1 - The first number.

d2 - The second number.

Returns:

True if the two doubles are equal.

hypot

public static double hypot(double a,
                           double b)

sqrt(a^2 + b^2) without under/overflow.

Parameters:

a - First param.

b - Second param.

Returns:

The result.

maxIndex

public static int maxIndex(double[] array)

Get the index to the greatest number in a double array.

Parameters:

array - The array to search.

Returns:

The index of the greatest value, or -1 if empty.

minIndex

public static int minIndex(double[] array)

Get the index to the smallest number in a double array.

Parameters:

array - The array to search.

Returns:

The index of the smallest value, or -1 if empty.

rad2deg

public static double rad2deg(double rad)

Convert radians to degrees.

Parameters:

rad - Radians

Returns:

Degrees.

factorial

public static double factorial(int x)

Calculate x!.

Parameters:

x - The number to calculate for.

Returns:

The factorial of x.

square

public static double square(double d)

sign

public static int sign(double value)

Determine the sign of the value.

Parameters:

value - The value to check.

Returns:

-1 if less than zero, 1 if greater, or 0 if zero.

thirds

public static int thirds(double value)

Transform a number in the range (-1,1) to a tri-state value indicated by -1, 0 or 1.

Parameters:

value - The value to consider.

Returns:

-1 if the value is below 1/3, 1 if above 1/3, zero otherwise.