org.dartra.util
Class MathTools

java.lang.Object
  org.dartra.util.MathTools

public class MathTools

extends java.lang.Object

Math tools for the J2ME CLDC 1.1 configuration. This implements the methods missing from java.lang.Math in CLDC 1.1.

Based on "henson.midp.Float", (C) by Nikolay Klimchuk.

Author:

Erwin Vervaet

Method Summary

static double	atan(double x) Returns the arc tangent of an angle, in the range of -pi/2 through pi/2.
static double	atan2(double y, double x) Converts rectangular coordinates (x, y) to polar (r, theta).

Methods inherited from class java.lang.Object

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

Method Detail

atan

public static double atan(double x)

Returns the arc tangent of an angle, in the range of -pi/2 through pi/2. Special cases:

• If the argument is NaN, then the result is NaN.
• If the argument is zero, then the result is a zero with the same sign as the argument.

A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.

Parameters:

x - the value whose arc tangent is to be returned.

Returns:

the arc tangent of the argument.

atan2

public static double atan2(double y,
                           double x)

Converts rectangular coordinates (x, y) to polar (r, theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi. Special cases:

• If either argument is NaN, then the result is NaN.
• If the first argument is positive zero and the second argument is positive, or the first argument is positive and finite and the second argument is positive infinity, then the result is positive zero.
• If the first argument is negative zero and the second argument is positive, or the first argument is negative and finite and the second argument is positive infinity, then the result is negative zero.
• If the first argument is positive zero and the second argument is negative, or the first argument is positive and finite and the second argument is negative infinity, then the result is the double value closest to pi.
• If the first argument is negative zero and the second argument is negative, or the first argument is negative and finite and the second argument is negative infinity, then the result is the double value closest to -pi.
• If the first argument is positive and the second argument is positive zero or negative zero, or the first argument is positive infinity and the second argument is finite, then the result is the double value closest to pi/2.
• If the first argument is negative and the second argument is positive zero or negative zero, or the first argument is negative infinity and the second argument is finite, then the result is the double value closest to -pi/2.
• If both arguments are positive infinity, then the result is the double value closest to pi/4.
• If the first argument is positive infinity and the second argument is negative infinity, then the result is the double value closest to 3*pi/4.
• If the first argument is negative infinity and the second argument is positive infinity, then the result is the double value closest to -pi/4.
• If both arguments are negative infinity, then the result is the double value closest to -3*pi/4.

A result must be within 2 ulps of the correctly rounded result. Results must be semi-monotonic.

Parameters:

y - the ordinate coordinate

x - the abscissa coordinate

Returns:

the theta component of the point (r, theta) in polar coordinates that corresponds to the point (x, y) in Cartesian coordinates.