Package com.google.common.math

Class BigDecimalMath

java.lang.Object

com.google.common.math.BigDecimalMath

@GwtIncompatible
public class BigDecimalMath
extends Object

A class for arithmetic on BigDecimal that is not covered by its built-in methods.

Since:

30.0

Author:

Louis Wasserman

Method Summary

Modifier and Type	Method	Description
static double	roundToDouble(BigDecimal x, RoundingMode mode)	Returns x, rounded to a double with the specified rounding mode.

Methods inherited from class java.lang.Object

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

Method Detail

roundToDouble

public static double roundToDouble(BigDecimal x,
                                   RoundingMode mode)

Returns x, rounded to a double with the specified rounding mode. If x is precisely representable as a double, its double value will be returned; otherwise, the rounding will choose between the two nearest representable values with mode.

For the case of RoundingMode.HALF_DOWN, HALF_UP, and HALF_EVEN, infinite double values are considered infinitely far away. For example, 2^2000 is not representable as a double, but roundToDouble(BigDecimal.valueOf(2).pow(2000), HALF_UP) will return Double.MAX_VALUE, not Double.POSITIVE_INFINITY.

For the case of RoundingMode.HALF_EVEN, this implementation uses the IEEE 754 default rounding mode: if the two nearest representable values are equally near, the one with the least significant bit zero is chosen. (In such cases, both of the nearest representable values are even integers; this method returns the one that is a multiple of a greater power of two.)

Throws:

ArithmeticException - if mode is RoundingMode.UNNECESSARY and x is not precisely representable as a double

Since:

30.0