Package de.tilman_neumann.jml.base

Class BigDecimalMath

java.lang.Object

de.tilman_neumann.jml.base.BigDecimalMath

public class BigDecimalMath
extends Object

Basic BigDecimal arithmetics.

Author:

Tilman Neumann

Method Summary

Modifier and Type	Method	Description
static BigDecimal	add(BigDecimal a, BigRational b, Scale resultScale)	Computes the sum of a and b accurate to the given resultScale. Scale is the natural accuracy measure for additions because for each argument, each piece of it (bit, digit, ...) makes its own independent contribution to the result scale.
static BigDecimal	add(BigDecimal a, BigInteger b)
static BigInteger	ceilInt(BigDecimal x)	Returns ceil(x) as a big integer.
static int	compare(BigDecimal a, BigInteger b)
static BigDecimal	divide(BigDecimal a, BigDecimal b, Precision resultPrecision)
static BigDecimal	divide(BigDecimal a, BigDecimal b, Scale resultScale)	Division with guaranteed precision.
static BigDecimal	divide(BigDecimal a, BigInteger b, Precision resultPrecision)
static BigDecimal	divide(BigDecimal a, BigInteger b, Scale resultScale)	Division by an integer.
static BigInteger	floorInt(BigDecimal x)	Returns floor(x) as a big integer.
static BigDecimal	frac(BigDecimal x)	Returns the fractional part of x, with the same scale than x.
static BigDecimal	multiply(BigDecimal a, long b)	Computes the product a*b without precision loss.
static BigDecimal	multiply(BigDecimal a, BigRational b, Precision resultPrecision)	Computes the product of a and b. Precision is the natural accuracy measure for multiplications because for each argument, each piece of it (bit, digit, ...) makes its own independent contribution to the result precision.
static BigDecimal	multiply(BigDecimal a, BigRational b, Scale resultScale)
static BigDecimal	multiply(BigDecimal a, BigInteger b)	Multiplication without precision loss.
static BigInteger	roundInt(BigDecimal x)	Round x to the nearest integer.
static BigDecimal	subtract(BigDecimal a, BigInteger b)	Computes the difference of a and b.

Methods inherited from class java.lang.Object

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

Method Detail

add

public static BigDecimal add(BigDecimal a,
                             BigRational b,
                             Scale resultScale)

Computes the sum of a and b accurate to the given resultScale.
Scale is the natural accuracy measure for additions because for each argument, each piece of it (bit, digit, ...) makes its own independent contribution to the result scale.

Parameters:

a -

b -

resultScale -

Returns:

sum

add

public static BigDecimal add(BigDecimal a,
                             BigInteger b)

subtract

public static BigDecimal subtract(BigDecimal a,
                                  BigInteger b)

Computes the difference of a and b.

Parameters:

a -

b -

Returns:

a-b

multiply

public static BigDecimal multiply(BigDecimal a,
                                  BigRational b,
                                  Precision resultPrecision)

Computes the product of a and b.
Precision is the natural accuracy measure for multiplications because for each argument, each piece of it (bit, digit, ...) makes its own independent contribution to the result precision.

Parameters:

a -

b -

resultPrecision -

Returns:

product

multiply

public static BigDecimal multiply(BigDecimal a,
                                  BigRational b,
                                  Scale resultScale)

multiply

public static BigDecimal multiply(BigDecimal a,
                                  BigInteger b)

Multiplication without precision loss.

Parameters:

a - big float

b - big integer

Returns:

a*b

multiply

public static BigDecimal multiply(BigDecimal a,
                                  long b)

Computes the product a*b without precision loss.

Parameters:

a -

b -

Returns:

a*b

divide

public static BigDecimal divide(BigDecimal a,
                                BigDecimal b,
                                Scale resultScale)

Division with guaranteed precision.

Parameters:

a - dividend

b - divisor

resultScale - result accuracy in decimal digits after the floating point

Returns:

a / b

divide

public static BigDecimal divide(BigDecimal a,
                                BigDecimal b,
                                Precision resultPrecision)

divide

public static BigDecimal divide(BigDecimal a,
                                BigInteger b,
                                Scale resultScale)

Division by an integer.

Parameters:

a - dividend

b - divisor

resultScale - result accuracy in decimal digits after the floating point

Returns:

quotient with wanted precision.

divide

public static BigDecimal divide(BigDecimal a,
                                BigInteger b,
                                Precision resultPrecision)

frac

public static BigDecimal frac(BigDecimal x)

Returns the fractional part of x, with the same scale than x.

Parameters:

x -

Returns:

frac(x)

roundInt

public static BigInteger roundInt(BigDecimal x)

Round x to the nearest integer.

Parameters:

x -

Returns:

round(x)

ceilInt

public static BigInteger ceilInt(BigDecimal x)

Returns ceil(x) as a big integer.

Parameters:

x -

Returns:

ceil(x)

floorInt

public static BigInteger floorInt(BigDecimal x)

Returns floor(x) as a big integer.

Parameters:

x -

Returns:

floor(x)

compare

public static int compare(BigDecimal a,
                          BigInteger b)

Parameters:

a -

b -

Returns:

<0/0/>0 if a is smaller/equal/greater than b.