com.nutiteq.utils

Class MathUtils

java.lang.Object

com.nutiteq.utils.MathUtils

public class MathUtils
extends Object

A utility class containing arithmetic and geometry helper methods.

Constructor Summary

Constructors

Constructor and Description
MathUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static float	getBearing(double latitude1, double longitude1, double latitude2, double longitude2) Gets the relative bearing from one geographical coordinate to another.
static float	getDistance(double latitude1, double longitude1, double latitude2, double longitude2) Gets the great circle distance in kilometers between two geographical points, using the haversine formula.
static int	getHalfWindIndex(float heading) Converts the specified heading angle into an index between 0-15 that can be used to retrieve the direction name for that heading (known as "boxing the compass", down to the half-wind level).
static float	mod(float a, float b) Calculates a mod b in a way that respects negative values (for example, mod(-1, 5) == 4, rather than -1).
static int	mod(int a, int b) Calculates a mod b in a way that respects negative values (for example, mod(-1, 5) == 4, rather than -1).

Methods inherited from class java.lang.Object

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

Constructor Detail

MathUtils

public MathUtils()

Method Detail

mod

public static int mod(int a,
      int b)

Calculates a mod b in a way that respects negative values (for example, mod(-1, 5) == 4, rather than -1).

Parameters:

a - the dividend

b - the divisor

Returns:

a mod b

mod

public static float mod(float a,
        float b)

Calculates a mod b in a way that respects negative values (for example, mod(-1, 5) == 4, rather than -1).

Parameters:

a - the dividend

b - the divisor

Returns:

a mod b

getHalfWindIndex

public static int getHalfWindIndex(float heading)

Converts the specified heading angle into an index between 0-15 that can be used to retrieve the direction name for that heading (known as "boxing the compass", down to the half-wind level).

Parameters:

heading - the heading angle

Returns:

the index of the direction name for the angle

getBearing

public static float getBearing(double latitude1,
               double longitude1,
               double latitude2,
               double longitude2)

Gets the relative bearing from one geographical coordinate to another.

Parameters:

latitude1 - the latitude of the source point

longitude1 - the longitude of the source point

latitude2 - the latitude of the destination point

longitude2 - the longitude of the destination point

Returns:

the relative bearing from point 1 to point 2, in degrees. The result is guaranteed to fall in the range 0-360

getDistance

public static float getDistance(double latitude1,
                double longitude1,
                double latitude2,
                double longitude2)

Gets the great circle distance in kilometers between two geographical points, using the haversine formula.

Parameters:

latitude1 - the latitude of the first point

longitude1 - the longitude of the first point

latitude2 - the latitude of the second point

longitude2 - the longitude of the second point

Returns:

the distance, in kilometers, between the two points