org.josef.science.math

Class CBigDecimal

java.lang.Object

java.lang.Number

java.math.BigDecimal

org.josef.science.math.CBigDecimal

All Implemented Interfaces:

Serializable, Comparable<BigDecimal>

@Status(stage=PRODUCTION,
        unitTests=COMPLETE)
 @Review(by="Kees Schotanus",
        at="2009-09-28")
 @ThreadSafety(level=IMMUTABLE)
public class CBigDecimal
extends BigDecimal

Abstraction of a decimal number with almost unlimited precision that extends BigDecimal.

Version:

1.1 $Revision: 6262 $

Author:

Kees Schotanus

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static CBigDecimal	HALF The constant value 0.5.
static CBigDecimal	TWO The constant value 2.

Fields inherited from class java.math.BigDecimal

ONE, ROUND_CEILING, ROUND_DOWN, ROUND_FLOOR, ROUND_HALF_DOWN, ROUND_HALF_EVEN, ROUND_HALF_UP, ROUND_UNNECESSARY, ROUND_UP, TEN, ZERO

Constructor Summary

Constructors

Constructor and Description
CBigDecimal(BigInteger value) Creates this CBigDecimal from the supplied value.
CBigDecimal(BigInteger unscaledValue, int scale) Creates this CBigDecimal from the supplied unscaledValue and scale.
CBigDecimal(double value) Creates this CBigDecimal from the supplied value.
CBigDecimal(int value) Creates this CBigDecimal from the supplied value.
CBigDecimal(long value) Creates this CBigDecimal from the supplied value.
CBigDecimal(String value) Creates this CBigDecimal from the supplied value.

Method Summary

Modifier and Type	Method and Description
static BigDecimal	squareRoot(BigDecimal value, int precision) Computes the square root of the supplied value.
BigDecimal	squareRoot(int precision) Computes the square root of this big decimal.

Methods inherited from class java.math.BigDecimal

abs, abs, add, add, byteValueExact, compareTo, divide, divide, divide, divide, divide, divide, divideAndRemainder, divideAndRemainder, divideToIntegralValue, divideToIntegralValue, doubleValue, equals, floatValue, hashCode, intValue, intValueExact, longValue, longValueExact, max, min, movePointLeft, movePointRight, multiply, multiply, negate, negate, plus, plus, pow, pow, precision, remainder, remainder, round, scale, scaleByPowerOfTen, setScale, setScale, setScale, shortValueExact, signum, stripTrailingZeros, subtract, subtract, toBigInteger, toBigIntegerExact, toEngineeringString, toPlainString, toString, ulp, unscaledValue, valueOf, valueOf, valueOf

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

TWO

public static final CBigDecimal TWO

The constant value 2.

HALF

public static final CBigDecimal HALF

The constant value 0.5.

Constructor Detail

CBigDecimal

public CBigDecimal(BigInteger unscaledValue,
                   int scale)

Creates this CBigDecimal from the supplied unscaledValue and scale.

Parameters:

unscaledValue - The unscaled value.

scale - The scale.

CBigDecimal

public CBigDecimal(BigInteger value)

Creates this CBigDecimal from the supplied value.

Parameters:

value - The value to create this CBigDecimal from.

CBigDecimal

public CBigDecimal(double value)

Creates this CBigDecimal from the supplied value.

Parameters:

value - The value to create this CBigDecimal from.

CBigDecimal

public CBigDecimal(int value)

Creates this CBigDecimal from the supplied value.

Parameters:

value - The value to create this CBigDecimal from.

CBigDecimal

public CBigDecimal(long value)

Creates this CBigDecimal from the supplied value.

Parameters:

value - The value to create this CBigDecimal from.

CBigDecimal

public CBigDecimal(String value)

Creates this CBigDecimal from the supplied value.

Parameters:

value - The value to create this CBigDecimal from.

Method Detail

squareRoot

public BigDecimal squareRoot(int precision)

Computes the square root of this big decimal.
See: squareRoot(BigDecimal, int) for details.

Parameters:

precision - The number of decimals to which the square root needs to be correct.
Technically the last digit may be off by one! So when 3.8145 is returned the result could either be 3.8144, 38145 or 3.8146!

Returns:

Approximate root of this big decimal.

Throws:

ArithmeticException - When this decimal is negative.

squareRoot

public static BigDecimal squareRoot(BigDecimal value,
                                    int precision)

Computes the square root of the supplied value.
This method uses the Babylonian method. This method can be derived from Newton's method but the Babylonian method is older.
Mathematically it works like this:
Assume the root of S needs to be calculated.
Start with an arbitrary positive as close to the root of S as possible.
Let x_n + 1 be the average of x_n and S / x_n.
The information above is from: Methods of computing square roots on WikiPedia.

Parameters:

value - The value to calculate the square root of.

precision - The number of decimals to which the square root needs to be correct.
Technically the last digit may be off by one! So when 3.8145 is returned the result could either be 3.8144, 38145 or 3.8146!

Returns:

Approximate root of the supplied value.

Throws:

ArithmeticException - When the supplied value is negative.