org.decimal4j.truncate

Enum DecimalRounding

java.lang.Object

java.lang.Enum<DecimalRounding>

org.decimal4j.truncate.DecimalRounding

All Implemented Interfaces:

Serializable, Comparable<DecimalRounding>

public enum DecimalRounding
extends Enum<DecimalRounding>

Defines the same constants as RoundingMode and implements the functionality to actually perform such rounding.

Enum Constant Summary

Enum Constants

Enum Constant and Description
CEILING Rounding mode to round towards positive infinity.
DOWN Rounding mode to round towards zero.
FLOOR Rounding mode to round towards negative infinity.
HALF_DOWN Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.
HALF_EVEN Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.
HALF_UP Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.
UNNECESSARY Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary.
UP Rounding mode to round away from zero.

Field Summary

Fields

Modifier and Type	Field and Description
static Set<DecimalRounding>	VALUES Immutable set with all values of this enum.

Method Summary

Methods

Modifier and Type	Method and Description
abstract int	calculateRoundingIncrement(int sign, long truncatedValue, TruncatedPart truncatedPart) Returns the rounding increment appropriate for this decimal rounding.
abstract RoundingMode	getRoundingMode() Returns the RoundingMode associated with this decimal rounding constant.
static DecimalRounding	valueOf(RoundingMode roundingMode) Returns the decimal rounding constant for the given rounding mode.
static DecimalRounding	valueOf(String name) Returns the enum constant of this type with the specified name.
static DecimalRounding[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

UP

public static final DecimalRounding UP

Rounding mode to round away from zero. Always increments the digit prior to a non-zero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value.

See Also:

RoundingMode.UP

DOWN

public static final DecimalRounding DOWN

Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value.

See Also:

RoundingMode.DOWN

CEILING

public static final DecimalRounding CEILING

Rounding mode to round towards positive infinity. If the result is positive, behaves as for RoundingMode.UP; if negative, behaves as for RoundingMode.DOWN. Note that this rounding mode never decreases the calculated value.

See Also:

RoundingMode.CEILING

FLOOR

public static final DecimalRounding FLOOR

Rounding mode to round towards negative infinity. If the result is positive, behave as for RoundingMode.DOWN; if negative, behave as for RoundingMode.UP. Note that this rounding mode never increases the calculated value.

See Also:

RoundingMode.FLOOR

HALF_UP

public static final DecimalRounding HALF_UP

Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. Behaves as for RoundingMode.UP if the discarded fraction is ≥ 0.5; otherwise, behaves as for RoundingMode.DOWN. Note that this is the rounding mode commonly taught at school.

See Also:

RoundingMode.HALF_UP

HALF_DOWN

public static final DecimalRounding HALF_DOWN

Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. Behaves as for RoundingMode.UP if the discarded fraction is > 0.5; otherwise, behaves as for RoundingMode.DOWN.

See Also:

RoundingMode.HALF_DOWN

HALF_EVEN

public static final DecimalRounding HALF_EVEN

Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as for RoundingMode.HALF_UP if the digit to the left of the discarded fraction is odd; behaves as for RoundingMode.HALF_DOWN if it's even. Note that this is the rounding mode that statistically minimizes cumulative error when applied repeatedly over a sequence of calculations. It is sometimes known as "Banker's rounding," and is chiefly used in the USA. This rounding mode is analogous to the rounding policy used for float and double arithmetic in Java.

See Also:

RoundingMode.HALF_EVEN

UNNECESSARY

public static final DecimalRounding UNNECESSARY

Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an ArithmeticException is thrown.

See Also:

RoundingMode.UNNECESSARY

Field Detail

VALUES

public static final Set<DecimalRounding> VALUES

Immutable set with all values of this enum. Avoids object creation in contrast to values().

Method Detail

values

public static DecimalRounding[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (DecimalRounding c : DecimalRounding.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static DecimalRounding valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getRoundingMode

public abstract RoundingMode getRoundingMode()

Returns the RoundingMode associated with this decimal rounding constant.

Returns:

the corresponding rounding mode

calculateRoundingIncrement

public abstract int calculateRoundingIncrement(int sign,
                             long truncatedValue,
                             TruncatedPart truncatedPart)

Returns the rounding increment appropriate for this decimal rounding. The returned value is one of -1, 0 or 1.

Parameters:

sign - the sign of the total value, either +1 or -1; determines the result value if rounded

truncatedValue - the truncated result before rounding is applied

truncatedPart - classification of the trunctated part of the value

Returns:

the value to add to truncatedValue to get the rounded result, one of -1, 0 or 1

valueOf

public static final DecimalRounding valueOf(RoundingMode roundingMode)

Returns the decimal rounding constant for the given rounding mode.

Parameters:

roundingMode - the rounding mode

Returns:

the constant corresponding to the given rounding mode