com.opengamma.strata.basics.value

Interface Rounding

public interface Rounding

A convention defining how to round a number.

This defines a standard mechanism for rounding a double, BigDecimal or Decimal. Since financial instruments have different and complex conventions, rounding is extensible.

Note that rounding a double is not straightforward as floating point numbers are based on a binary representation, not a decimal one. For example, the value 0.1 cannot be exactly represented in a double.

The standard implementation is HalfUpRounding. Additional implementations may be added by implementing this interface.

All implementations of this interface must be immutable and thread-safe.

Method Summary

Modifier and Type	Method and Description
static Rounding	none() Obtains an instance that performs no rounding.
static Rounding	of(Currency currency) Obtains an instance that rounds to the number of minor units in the currency.
static Rounding	ofDecimalPlaces(int decimalPlaces) Obtains an instance that rounds to the specified number of decimal places.
static Rounding	ofFractionalDecimalPlaces(int decimalPlaces, int fraction) Obtains an instance from the number of decimal places and fraction.
BigDecimal	round(BigDecimal value) Rounds the specified value according to the rules of the convention.
default Decimal	round(Decimal value) Rounds the specified value according to the rules of the convention.
default double	round(double value) Rounds the specified value according to the rules of the convention.

Method Detail

none

static Rounding none()

Obtains an instance that performs no rounding.

Returns:

the rounding convention

of

static Rounding of(Currency currency)

Obtains an instance that rounds to the number of minor units in the currency.

This returns a convention that rounds for the specified currency. Rounding follows the normal RoundingMode.HALF_UP convention.

Parameters:

currency - the currency

Returns:

the rounding convention

ofDecimalPlaces

static Rounding ofDecimalPlaces(int decimalPlaces)

Obtains an instance that rounds to the specified number of decimal places.

This returns a convention that rounds to the specified number of decimal places. Rounding follows the normal RoundingMode.HALF_UP convention.

Parameters:

decimalPlaces - the number of decimal places to round to, from 0 to 255 inclusive

Returns:

the rounding convention

Throws:

IllegalArgumentException - if the decimal places is invalid

ofFractionalDecimalPlaces

static Rounding ofFractionalDecimalPlaces(int decimalPlaces,
                                          int fraction)

Obtains an instance from the number of decimal places and fraction.

This returns a convention that rounds to a fraction of the specified number of decimal places. Rounding follows the normal RoundingMode.HALF_UP convention.

For example, to round to the nearest 1/32nd of the 4th decimal place, call this method with the arguments 4 and 32.

Parameters:

decimalPlaces - the number of decimal places to round to, from 0 to 255 inclusive

fraction - the fraction of the last decimal place, such as 32 for 1/32, from 0 to 255 inclusive

Returns:

the rounding convention

Throws:

IllegalArgumentException - if the decimal places or fraction is invalid

round

default double round(double value)

Rounds the specified value according to the rules of the convention.

Parameters:

value - the value to be rounded

Returns:

the rounded value

round

BigDecimal round(BigDecimal value)

Rounds the specified value according to the rules of the convention.

Parameters:

value - the value to be rounded

Returns:

the rounded value

round

default Decimal round(Decimal value)

Rounds the specified value according to the rules of the convention.

Parameters:

value - the value to be rounded

Returns:

the rounded value