texsoft.java.util
Class XsMath

java.lang.Object
  |
  +--texsoft.java.util.XsMath

public abstract class XsMath

extends java.lang.Object

This abstract class provides some math static methods, moslty for rounding purposes.

Constructor Summary

XsMath()

Method Summary

static double	log10(double x) Returns the log10 of x.
static void	main(java.lang.String[] args) Simple test code.
static double	pow10(int pow) Return 10pow.
static double	round(double value, int log) Round value to log decimal weight.
static double	roundDown(double value, int log) Round DOWN value to log decimal weight.
static double	roundUp(double value, int log) Round UP value to log decimal weight.
static double	trunc(double value, int log) Truncate value to log decimal weight.

Methods inherited from class java.lang.Object

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

Constructor Detail

XsMath

public XsMath()

Method Detail

trunc

public static double trunc(double value,
                           int log)

Truncate value to log decimal weight.

Use negative log value for decimal. Examples:

 trunc(123.456, -4) = 123.456
 trunc(123.456, -3) = 123.456
 trunc(123.456, -2) = 123.45
 trunc(123.456, -1) = 123.4
 trunc(123.456,  0) = 123.0
 trunc(123.456,  1) = 120.0
 trunc(123.456,  2) = 100.0
 trunc(123.456,  3) = 0.0
 

Parameters:

value - value to be truncated.

log - truncate value to the this decimal weight. Negative values mean decimal positions.

Returns:

value truncated to the given decimal weight.

round

public static double round(double value,
                           int log)

Round value to log decimal weight.

Use negative log value for decimals. Examples:

 round(123.446, -4)=123.446
 round(123.446, -3)=123.446
 round(123.446, -2)=123.45
 round(123.446, -1)=123.4
 round(123.446, 0)=123.0
 round(123.446, 1)=120.0
 round(153.446, 2)=200.0
 round(123.446, 3)=0.0
 

Parameters:

value - value to be rounded.

log - round value to the this decimal weight. Negative values mean decimal positions.

Returns:

value rounded to the given decimal weight.

roundUp

public static double roundUp(double value,
                             int log)

Round UP value to log decimal weight.

Use negative log value for decimals. Examples:

 roundUp(123.456, -4) = 123.456
 roundUp(123.456, -3) = 123.456
 roundUp(123.456, -2) = 123.46
 roundUp(123.456, -1) = 123.5
 roundUp(123.456, 0)  = 124.0
 roundUp(123.456, 1)  = 130.0
 roundUp(123.456, 2)  = 200.0
 roundUp(123.456, 3)  = 1000.0
 

Parameters:

value - value to be rounded up.

log - round up value to the this decimal weight. Negative values mean decimal positions.

Returns:

value rounded up to the given decimal weight.

roundDown

public static double roundDown(double value,
                               int log)

Round DOWN value to log decimal weight.

Use negative log value for decimals. Examples:

 roundDown(123.456, -4)=123.456
 roundDown(123.456, -3)=123.456
 roundDown(123.456, -2)=123.45
 roundDown(123.456, -1)=123.4
 roundDown(123.456, 0)=123.0
 roundDown(123.456, 1)=120.0
 roundDown(123.456, 2)=100.0
 roundDown(123.456, 3)=0.0
 

Parameters:

value - value to be rounded down.

log - round down value to the this decimal weight. Negative values mean decimal positions.

Returns:

value rounded down to the given decimal weight.

pow10

public static double pow10(int pow)

Return 10^pow.

Parameters:

pow - exponent.

Returns:

10^pow.

log10

public static double log10(double x)

Returns the log₁₀ of x.

Parameters:

x - value whose log₁₀ has to be calculated.

Returns:

log₁₀ of x.

main

public static void main(java.lang.String[] args)

Simple test code.

Parameters:

args - command line arguments.