net.openhft.lang

Class Maths

java.lang.Object

net.openhft.lang.Maths

public class Maths
extends Object

Author:

peter.lawrey

Field Summary

Fields

Modifier and Type	Field and Description
static double	WHOLE_NUMBER Numbers larger than this are whole numbers due to representation error.

Constructor Summary

Constructors

Constructor and Description
Maths()

Method Summary

Methods

Modifier and Type	Method and Description
static int	compare(long x, long y) Compares two long values numerically.
static long	hash(CharSequence cs)
static int	hash(int n)
static int	hash(long n)
static int	intLog2(long num)
static int	nextPower2(int n, int min)
static long	nextPower2(long n, long min)
static long	power10(int n)
static double	round2(double d) Performs a round which is accurate to within 1 ulp.
static double	round4(double d) Performs a round which is accurate to within 1 ulp.
static double	round6(double d) Performs a round which is accurate to within 1 ulp.
static double	round8(double d) Performs a round which is accurate to within 1 ulp.

Methods inherited from class java.lang.Object

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

Field Detail

WHOLE_NUMBER

public static final double WHOLE_NUMBER

Numbers larger than this are whole numbers due to representation error.

See Also:

Constant Field Values

Constructor Detail

Maths

public Maths()

Method Detail

round2

public static double round2(double d)

Performs a round which is accurate to within 1 ulp. i.e. for values very close to 0.5 it might be rounded up or down. This is a pragmatic choice for performance reasons as it is assumed you are not working on the edge of the precision of double.

Parameters:

d - value to round

round4

public static double round4(double d)

Performs a round which is accurate to within 1 ulp. i.e. for values very close to 0.5 it might be rounded up or down. This is a pragmatic choice for performance reasons as it is assumed you are not working on the edge of the precision of double.

Parameters:

d - value to round

round6

public static double round6(double d)

Performs a round which is accurate to within 1 ulp. i.e. for values very close to 0.5 it might be rounded up or down. This is a pragmatic choice for performance reasons as it is assumed you are not working on the edge of the precision of double.

Parameters:

d - value to round

round8

public static double round8(double d)

Performs a round which is accurate to within 1 ulp. i.e. for values very close to 0.5 it might be rounded up or down. This is a pragmatic choice for performance reasons as it is assumed you are not working on the edge of the precision of double.

Parameters:

d - value to round

power10

public static long power10(int n)

nextPower2

public static int nextPower2(int n,
             int min)

nextPower2

public static long nextPower2(long n,
              long min)

hash

public static int hash(int n)

hash

public static int hash(long n)

hash

public static long hash(CharSequence cs)

compare

public static int compare(long x,
          long y)

Compares two long values numerically. The value returned is identical to what would be returned by:

    Long.valueOf(x).compareTo(Long.valueOf(y))
 

Parameters:

x - the first long to compare

y - the second long to compare

Returns:

the value 0 if x == y; a value less than 0 if x < y; and a value greater than 0 if x > y

intLog2

public static int intLog2(long num)