org.granite.math.RoundingMode

Package	org.granite.math
Class	public final class RoundingMode
Inheritance	RoundingMode Enum

Specifies a rounding behavior for numerical operations capable of discarding precision. Each rounding mode indicates how the least significant returned digit of a rounded result is to be calculated. If fewer digits are returned than the digits needed to represent the exact numerical result, the discarded digits will be referred to as the discarded fraction regardless the digits' contribution to the value of the number. In other words, considered as a numerical value, the discarded fraction could have an absolute value greater than one.

Each rounding mode description includes a table listing how different two-digit decimal values would round to a one digit decimal value under the rounding mode in question. The result column in the tables could be gotten by creating a BigDecimal number with the specified value, forming a MathContext object with the proper settings (precision set to 1, and the roundingMode set to the rounding mode in question), and calling BigDecimal.round on this number with the proper MathContext. A summary table showing the results of these rounding operations for all rounding modes appears below.

This class is basically an ActionScript3 port of the Java class java.math.RoundingMode originally written by Josh Bloch, Mike Cowlishaw and Joseph D. Darcy.

See also

BigDecimal.html
MathContext.html

	Property	Defined by
		name : String	Enum

	Property	Defined by
		_ : Restrictor [static]	Enum

	Method	Defined by
		checkForConstant(o:): [static]	Enum
		equals(other:Enum):Boolean	Enum
		normalize(tmp:Enum):Enum [static]	Enum
		readEnum(input:IDataInput):Enum [static]	Enum
		readExternal(input:IDataInput):void	Enum
		toString():String	Enum
		valueOf(name:String):RoundingMode [static] Returns a `RoundingMode` constant according to the supplied parameter.	RoundingMode
		writeExternal(output:IDataOutput):void	Enum

	Method	Defined by
		constantOf(name:String):Enum	Enum
		getConstants():Array	Enum

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

Method detail

valueOf

()

method

public static function valueOf(name:String):RoundingMode

Returns a RoundingMode constant according to the supplied parameter.

Parameters

name:String — a RoundingMode constant name.

Returns

RoundingMode — a RoundingMode constant.

Throws

IllegalArgumentError — if the name parameter does not specify a RoundingMode constant name.

Constant detail

CEILING

constant

public static const CEILING:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `CEILING` rounding
5.5	6
2.5	3
1.6	2
1.1	2
1.0	1
-1.0	-1
-1.1	-1
-1.6	-1
-2.5	-2
-5.5	-5

DOWN

constant

public static const DOWN:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `DOWN` rounding
5.5	5
2.5	2
1.6	1
1.1	1
1.0	1
-1.0	-1
-1.1	-1
-1.6	-1
-2.5	-2
-5.5	-5

FLOOR

constant

public static const FLOOR:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `FLOOR` rounding
5.5	5
2.5	2
1.6	1
1.1	1
1.0	1
-1.0	-1
-1.1	-2
-1.6	-2
-2.5	-3
-5.5	-6

HALF_DOWN

constant

public static const HALF_DOWN:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `HALF_DOWN` rounding
5.5	5
2.5	2
1.6	2
1.1	1
1.0	1
-1.0	-1
-1.1	-1
-1.6	-2
-2.5	-2
-5.5	-5

HALF_EVEN

constant

public static const HALF_EVEN:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `HALF_EVEN` rounding
5.5	6
2.5	2
1.6	2
1.1	1
1.0	1
-1.0	-1
-1.1	-1
-1.6	-2
-2.5	-2
-5.5	-6

HALF_UP

constant

public static const HALF_UP:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `HALF_UP` rounding
5.5	6
2.5	3
1.6	2
1.1	1
1.0	1
-1.0	-1
-1.1	-1
-1.6	-2
-2.5	-3
-5.5	-6

UNNECESSARY

constant

public static const UNNECESSARY:RoundingMode

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 BigNumberError is thrown.

Example:

Input Number	Input rounded to one digit with `UNNECESSARY` rounding
5.5	throw `BigNumberError`
2.5	throw `BigNumberError`
1.6	throw `BigNumberError`
1.1	throw `BigNumberError`
1.0	1
-1.0	-1
-1.1	throw `BigNumberError`
-1.6	throw `BigNumberError`
-2.5	throw `BigNumberError`
-5.5	throw `BigNumberError`

constant

public static const UP:RoundingMode

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.

Example:

Input Number	Input rounded to one digit with `UP` rounding
5.5	6
2.5	3
1.6	2
1.1	2
1.0	1
-1.0	-1
-1.1	-2
-1.6	-2
-2.5	-3
-5.5	-6

Granite Data Services API Documentation (3.0.0.M2)	All Packages \| All Classes \| Index \| Frames No Frames
Class RoundingMode	Properties \| Methods \| Constants