International Components for Unicode for Java (icu4j) 74.2 · com.ibm.icu.impl.number.RoundingUtils

Modifier and Type	Field and Description
public static final MathContext	DEFAULT_MATH_CONTEXT_34_DIGITS The default MathContext, 34-digit version.
public static final MathContext	DEFAULT_MATH_CONTEXT_UNLIMITED The default MathContext, unlimited-precision version.
public static final RoundingMode	DEFAULT_ROUNDING_MODE The default rounding mode.
private static final MathContext[]	MATH_CONTEXT_BY_ROUNDING_MODE_34_DIGITS
private static final MathContext[]	MATH_CONTEXT_BY_ROUNDING_MODE_UNLIMITED
public static final int	MAX_INT_FRAC_SIG The maximum number of fraction places, integer numerals, or significant digits.
public static final int	SECTION_LOWER
public static final int	SECTION_MIDPOINT
public static final int	SECTION_UPPER

Access	Constructor and Description
public	RoundingUtils()

Method Summary

Modifier and Type	Method and Description
public static MathContext	Returns: A `MathContext`. Never null. getMathContextOr34Digits(DecimalFormatProperties The property bag. properties) Gets the user-specified math context out of the property bag.
public static MathContext	Returns: A `MathContext`. Never null. getMathContextOrUnlimited(DecimalFormatProperties The property bag. properties) Gets the user-specified math context out of the property bag.
public static StandardPlural	getPluralSafe(Precision rounder, PluralRules rules, DecimalQuantity dq) Deprecated as a consequence of `DecimalQuantity` being deprecated. Computes the plural form after copying the number and applying rounding rules.
public static boolean	Returns: true if the number should be rounded toward zero; false if it should be rounded toward infinity. getRoundingDirection(boolean Whether the digit immediately before the rounding magnitude is even. isEven, boolean Whether the quantity is negative. isNegative, int Whether the part of the quantity to the right of the rounding magnitude is exactly halfway between two digits, whether it is in the lower part (closer to zero), or whether it is in the upper part (closer to infinity). See `SECTION_LOWER`, `SECTION_MIDPOINT`, and `SECTION_UPPER`. section, int The integer version of the `RoundingMode`, which you can get via `RoundingMode#ordinal`. roundingMode, Object A reference object to be used when throwing an ArithmeticException. reference) Converts a rounding mode and metadata about the quantity being rounded to a boolean determining whether the value should be rounded toward infinity or toward zero.
public static MathContext	Returns: The corresponding `MathContext`. mathContextUnlimited(RoundingMode The `RoundingMode` to use. roundingMode) Gets a MathContext with unlimited precision and the specified RoundingMode.
public static boolean	Returns: true if rounding mode is HALF_EVEN, HALF_UP, or HALF_DOWN; false otherwise. roundsAtMidpoint(int The integer version of the `RoundingMode`. roundingMode) Gets whether the given rounding mode's rounding boundary is at the midpoint.
public static Scale	scaleFromProperties(DecimalFormatProperties properties)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

DEFAULT_MATH_CONTEXT_34_DIGITS	back to summary
public static final MathContext DEFAULT_MATH_CONTEXT_34_DIGITS The default MathContext, 34-digit version.

DEFAULT_MATH_CONTEXT_UNLIMITED	back to summary
public static final MathContext DEFAULT_MATH_CONTEXT_UNLIMITED The default MathContext, unlimited-precision version.

DEFAULT_ROUNDING_MODE	back to summary
public static final RoundingMode DEFAULT_ROUNDING_MODE The default rounding mode.

MATH_CONTEXT_BY_ROUNDING_MODE_34_DIGITS	back to summary
private static final MathContext[] MATH_CONTEXT_BY_ROUNDING_MODE_34_DIGITS

MATH_CONTEXT_BY_ROUNDING_MODE_UNLIMITED	back to summary
private static final MathContext[] MATH_CONTEXT_BY_ROUNDING_MODE_UNLIMITED

MAX_INT_FRAC_SIG	back to summary
public static final int MAX_INT_FRAC_SIG The maximum number of fraction places, integer numerals, or significant digits. Todo This does not feel like the best home for this value.

SECTION_LOWER	back to summary
public static final int SECTION_LOWER

SECTION_MIDPOINT	back to summary
public static final int SECTION_MIDPOINT

SECTION_UPPER	back to summary
public static final int SECTION_UPPER

Constructor Detail

RoundingUtils	back to summary
public RoundingUtils()

Method Detail

getMathContextOr34Digits back to summary

getMathContextOr34Digits	back to summary
public static MathContext getMathContextOr34Digits(DecimalFormatProperties properties) Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with 34 digits of precision (the 128-bit IEEE 754R default) and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default). Parameters properties:DecimalFormatProperties The property bag. Returns:MathContext A `MathContext`. Never null.

public static MathContext getMathContextOr34Digits(DecimalFormatProperties properties)

Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with 34 digits of precision (the 128-bit IEEE 754R default) and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default).

Parameters

properties:DecimalFormatProperties: The property bag.

Returns:MathContext

A MathContext. Never null.

getMathContextOrUnlimited back to summary

getMathContextOrUnlimited	back to summary
public static MathContext getMathContextOrUnlimited(DecimalFormatProperties properties) Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with unlimited precision and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default). Parameters properties:DecimalFormatProperties The property bag. Returns:MathContext A `MathContext`. Never null.

public static MathContext getMathContextOrUnlimited(DecimalFormatProperties properties)

Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with unlimited precision and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default).

Parameters

properties:DecimalFormatProperties: The property bag.

Returns:MathContext

A MathContext. Never null.

getPluralSafe	back to summary
public static StandardPlural getPluralSafe(Precision rounder, PluralRules rules, DecimalQuantity dq) Deprecated as a consequence of `DecimalQuantity` being deprecated. See corresponding docs for further information. Computes the plural form after copying the number and applying rounding rules.

getRoundingDirection back to summary

getRoundingDirection	back to summary
public static boolean getRoundingDirection(boolean isEven, boolean isNegative, int section, int roundingMode, Object reference) Converts a rounding mode and metadata about the quantity being rounded to a boolean determining whether the value should be rounded toward infinity or toward zero. The parameters are of type int because benchmarks on an x86-64 processor against OpenJDK showed that ints were demonstrably faster than enums in switch statements. Parameters isEven:boolean Whether the digit immediately before the rounding magnitude is even. isNegative:boolean Whether the quantity is negative. section:int Whether the part of the quantity to the right of the rounding magnitude is exactly halfway between two digits, whether it is in the lower part (closer to zero), or whether it is in the upper part (closer to infinity). See `SECTION_LOWER`, `SECTION_MIDPOINT`, and `SECTION_UPPER`. roundingMode:int The integer version of the `RoundingMode`, which you can get via `RoundingMode#ordinal`. reference:Object A reference object to be used when throwing an ArithmeticException. Returns:boolean true if the number should be rounded toward zero; false if it should be rounded toward infinity.

public static boolean getRoundingDirection(boolean isEven, boolean isNegative, int section, int roundingMode, Object reference)

Converts a rounding mode and metadata about the quantity being rounded to a boolean determining whether the value should be rounded toward infinity or toward zero.

The parameters are of type int because benchmarks on an x86-64 processor against OpenJDK showed that ints were demonstrably faster than enums in switch statements.

Parameters

isEven:boolean: Whether the digit immediately before the rounding magnitude is even.
isNegative:boolean: Whether the quantity is negative.
section:int: Whether the part of the quantity to the right of the rounding magnitude is exactly halfway between two digits, whether it is in the lower part (closer to zero), or whether it is in the upper part (closer to infinity). See SECTION_LOWER, SECTION_MIDPOINT, and SECTION_UPPER.
roundingMode:int: The integer version of the RoundingMode, which you can get via RoundingMode#ordinal.
reference:Object: A reference object to be used when throwing an ArithmeticException.

Returns:boolean

true if the number should be rounded toward zero; false if it should be rounded toward infinity.

mathContextUnlimited back to summary

mathContextUnlimited	back to summary
public static MathContext mathContextUnlimited(RoundingMode roundingMode) Gets a MathContext with unlimited precision and the specified RoundingMode. Equivalent to "new MathContext(0, roundingMode)", but pulls from a singleton to prevent object thrashing. Parameters roundingMode:RoundingMode The `RoundingMode` to use. Returns:MathContext The corresponding `MathContext`.

public static MathContext mathContextUnlimited(RoundingMode roundingMode)

Gets a MathContext with unlimited precision and the specified RoundingMode. Equivalent to "new MathContext(0, roundingMode)", but pulls from a singleton to prevent object thrashing.

Parameters

roundingMode:RoundingMode: The RoundingMode to use.

Returns:MathContext

The corresponding MathContext.

roundsAtMidpoint back to summary

roundsAtMidpoint	back to summary
public static boolean roundsAtMidpoint(int roundingMode) Gets whether the given rounding mode's rounding boundary is at the midpoint. The rounding boundary is the point at which a number switches from being rounded down to being rounded up. For example, with rounding mode HALF_EVEN, HALF_UP, or HALF_DOWN, the rounding boundary is at the midpoint, and this function would return true. However, for UP, DOWN, CEILING, and FLOOR, the rounding boundary is at the "edge", and this function would return false. Parameters roundingMode:int The integer version of the `RoundingMode`. Returns:boolean true if rounding mode is HALF_EVEN, HALF_UP, or HALF_DOWN; false otherwise.

public static boolean roundsAtMidpoint(int roundingMode)

Gets whether the given rounding mode's rounding boundary is at the midpoint. The rounding boundary is the point at which a number switches from being rounded down to being rounded up. For example, with rounding mode HALF_EVEN, HALF_UP, or HALF_DOWN, the rounding boundary is at the midpoint, and this function would return true. However, for UP, DOWN, CEILING, and FLOOR, the rounding boundary is at the "edge", and this function would return false.

Parameters

roundingMode:int: The integer version of the RoundingMode.

Returns:boolean

true if rounding mode is HALF_EVEN, HALF_UP, or HALF_DOWN; false otherwise.

scaleFromProperties	back to summary
public static Scale scaleFromProperties(DecimalFormatProperties properties)

public Class RoundingUtils

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