Class NumberContext

java.lang.Object

org.ojalgo.type.context.FormatContext<Comparable<?>>

org.ojalgo.type.context.NumberContext

All Implemented Interfaces:

TypeContext<Comparable<?>>

public final class NumberContext
extends FormatContext<Comparable<?>>

Think of this as a MathContext that specifies both precision and scale. Numeric data types (non-integers) in databases are specified using precision and scale. While doing maths the precision is all that matters, but before sending a number to a database, or printing/displaying it, rounding to a specified scale is desirable.

The enforce methods first enforce the precision and then set the scale. It is possible that this will create a number with trailing zeros and more digits than the precision allows. It is also possible to define a context with a scale that is larger than the precision. This is NOT how precision and scale is used with numeric types in databases.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	NumberContext.Enforceable<T>
static interface	NumberContext.FormatPattern

Field Summary

Fields

Modifier and Type	Field	Description
private static final MathContext	DEFAULT_MATH
private static final int	DEFAULT_SCALE
private static final NumberStyle	DEFAULT_STYLE
private final double	myAbsoluteError
private final MathContext	myMathContext
private final double	myRelativeError
private final double	myRoundingFactor
private final int	myScale

Fields inherited from class FormatContext

NBSP

Constructor Summary

Constructors

Modifier	Constructor	Description
private	NumberContext(NumberFormat format, int precision, int scale, RoundingMode mode)
(package private)	NumberContext(NumberFormat format, MathContext math, int scale)

Method Summary

Modifier and Type	Method	Description
static int	compare(double arg1, double arg2)	Variation of Double.compare(double, double) that returns 0 if arg1 == arg2.
static int	compare(float arg1, float arg2)	Variation of Float.compare(float, float) that returns 0 if arg1 == arg2.
protected void	configureFormat(Format format, Object object)
double	enforce(double number)	If precision is specified then this method instantiates a BigDecimal, enforces that, and then extracts a double again.
Comparable<?>	enforce(Comparable<?> object)	Will force the object to conform to the context's specification.
BigDecimal	enforce(BigDecimal number)	Will first enforce the precision, and then the scale.
double	epsilon()	Deprecated. v56 Use error(double) instead.
boolean	equals(Object obj)
double	error(double value)	Returns the tolerance for a value with the given magnitude.
String	format(double number)
String	format(long number)
double	getAbsoluteError()	The absolute error is half the size of the last decimal place (scale).
static NumberContext	getCurrency(Locale locale)
NumberFormat	getFormat()
<N extends Comparable<N>> UnaryFunction<N>	getFunction(FunctionSet<N> functions)
static NumberContext	getInteger(Locale locale)
MathContext	getMathContext()
static NumberContext	getPercent(int scale, Locale locale)
static NumberContext	getPercent(Locale locale)
int	getPrecision()
double	getRelativeError()	The relative error is defined as the difference between 1 and the next larger decimal number with the given number of digits (precision).
RoundingMode	getRoundingMode()
int	getScale()
protected String	handleFormatException(Format format, Object object)
protected Comparable<?>	handleParseException(Format format, String string)
int	hashCode()
boolean	isDifferent(double expected, double actual)
boolean	isInteger(double value)
boolean	isLessThan(BigDecimal reference, BigDecimal value)
boolean	isMinimal(BigDecimal value)	The absolute smallest number allowed by this context, but not zero.
boolean	isMoreThan(BigDecimal reference, BigDecimal value)
boolean	isSmall(double comparedTo, double value)
boolean	isSmall(BigDecimal comparedTo, BigDecimal value)
boolean	isZero(double value)
private static boolean	isZero(double value, double tolerance)
boolean	isZero(BigDecimal value)
static NumberContext	of(int precisionAndScale)
static NumberContext	of(int precision, int scale)
static NumberContext	ofMath(MathContext math)
static NumberContext	ofPrecision(int precision)
static NumberContext	ofScale(int scale)
private BigDecimal	scale(BigDecimal number)
BigDecimal	toBigDecimal(double number)	Will create an "enforced" BigDecimal instance.
static Format	toFormat(NumberStyle style, Locale locale)
String	toLocalizedPattern()	Works with DecimalFormat and NumberContext.FormatPattern implementations.
String	toPattern()	Works with DecimalFormat and NumberContext.FormatPattern implementations.
String	toString()
NumberContext	withDecrementedPrecision()
NumberContext	withDecrementedPrecision(int subtrahend)
NumberContext	withDecrementedScale()
NumberContext	withDecrementedScale(int subtrahend)
NumberContext	withDoubledPrecision()
NumberContext	withDoubledScale()
NumberContext	withFormat(NumberStyle style, Locale locale)
NumberContext	withHalvedPrecision()
NumberContext	withHalvedScale()
NumberContext	withIncrementedPrecision()
NumberContext	withIncrementedPrecision(int addend)
NumberContext	withIncrementedScale()
NumberContext	withIncrementedScale(int addend)
NumberContext	withMath(MathContext math)
NumberContext	withMode(RoundingMode mode)
NumberContext	withoutPrecision()
NumberContext	withoutScale()
NumberContext	withPrecision(int precision)
NumberContext	withScale(int scale)

Methods inherited from class FormatContext

format, format, isConfigured, parse, withFormat

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

DEFAULT_MATH

private static final MathContext DEFAULT_MATH

DEFAULT_SCALE

private static final int DEFAULT_SCALE

See Also:

• Constant Field Values

DEFAULT_STYLE

private static final NumberStyle DEFAULT_STYLE

myAbsoluteError

private final double myAbsoluteError

myMathContext

private final MathContext myMathContext

myRelativeError

private final double myRelativeError

myRoundingFactor

private final double myRoundingFactor

myScale

private final int myScale

Constructor Details

NumberContext

private NumberContext(NumberFormat format,
 int precision,
 int scale,
 RoundingMode mode)

NumberContext

NumberContext(NumberFormat format,
 MathContext math,
 int scale)

Method Details

compare

public static int compare(double arg1,
 double arg2)

Variation of Double.compare(double, double) that returns 0 if arg1 == arg2.

compare

public static int compare(float arg1,
 float arg2)

Variation of Float.compare(float, float) that returns 0 if arg1 == arg2.

getCurrency

public static NumberContext getCurrency(Locale locale)

getInteger

public static NumberContext getInteger(Locale locale)

getPercent

public static NumberContext getPercent(int scale,
 Locale locale)

getPercent

public static NumberContext getPercent(Locale locale)

of

public static NumberContext of(int precisionAndScale)

of

public static NumberContext of(int precision,
 int scale)

ofMath

public static NumberContext ofMath(MathContext math)

ofPrecision

public static NumberContext ofPrecision(int precision)

ofScale

public static NumberContext ofScale(int scale)

toFormat

public static Format toFormat(NumberStyle style,
 Locale locale)

isZero

private static boolean isZero(double value,
 double tolerance)

enforce

public BigDecimal enforce(BigDecimal number)

Will first enforce the precision, and then the scale. Both operations will comply with the rounding mode.

enforce

public Comparable<?> enforce(Comparable<?> object)

Description copied from interface: TypeContext

Will force the object to conform to the context's specification. The default implementation formats a String and then parses that back to an object (of the original type).

enforce

public double enforce(double number)

If precision is specified then this method instantiates a BigDecimal, enforces that, and then extracts a double again.

If only a scale is specified then this enforces without creating any objects. In this case the precision is given by the type double and the rounding mode is always "half even" as given by Math.rint(double) (regardless of what rounding mode is specified).

epsilon

@Deprecated
public double epsilon()

Deprecated.

v56 Use error(double) instead.

The larger of the two errors (relative and absolute).

This is equivalent to calling error(double) with magnitude = 1.

See Also:

• getRelativeError()
• getAbsoluteError()
• error(double)

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

See Also:

• Object.equals(java.lang.Object)

error

public double error(double value)

Returns the tolerance for a value with the given magnitude.

tolerance/error = max(absoluteError, abs(magnitude) * relativeError)

See Also:

• getRelativeError()
• getAbsoluteError()
• epsilon()

format

public String format(double number)

format

public String format(long number)

getAbsoluteError

public double getAbsoluteError()

The absolute error is half the size of the last decimal place (scale).

getFormat

public NumberFormat getFormat()

Overrides:

getFormat in class FormatContext<Comparable<?>>

getFunction

public <N extends Comparable<N>> UnaryFunction<N> getFunction(FunctionSet<N> functions)

getMathContext

public MathContext getMathContext()

getPrecision

public int getPrecision()

getRelativeError

public double getRelativeError()

The relative error is defined as the difference between 1 and the next larger decimal number with the given number of digits (precision).

getRoundingMode

public RoundingMode getRoundingMode()

getScale

public int getScale()

hashCode

public int hashCode()

Overrides:

hashCode in class Object

See Also:

• Object.hashCode()

isDifferent

public boolean isDifferent(double expected,
 double actual)

isInteger

public boolean isInteger(double value)

isLessThan

public boolean isLessThan(BigDecimal reference,
 BigDecimal value)

isMinimal

public boolean isMinimal(BigDecimal value)

The absolute smallest number allowed by this context, but not zero. A single ±1 at the very last decimal place.

Say you rounded a number to scale 4 and ended up with a number that is ±1E-4.

isMoreThan

public boolean isMoreThan(BigDecimal reference,
 BigDecimal value)

isSmall

public boolean isSmall(BigDecimal comparedTo,
 BigDecimal value)

isSmall

public boolean isSmall(double comparedTo,
 double value)

isZero

public boolean isZero(BigDecimal value)

isZero

public boolean isZero(double value)

toBigDecimal

public BigDecimal toBigDecimal(double number)

Will create an "enforced" BigDecimal instance.

toLocalizedPattern

public String toLocalizedPattern()

Works with DecimalFormat and NumberContext.FormatPattern implementations. In other cases it returns null.

toPattern

public String toPattern()

Works with DecimalFormat and NumberContext.FormatPattern implementations. In other cases it returns null.

toString

public String toString()

Overrides:

toString in class Object

withDecrementedPrecision

public NumberContext withDecrementedPrecision()

withDecrementedPrecision

public NumberContext withDecrementedPrecision(int subtrahend)

withDecrementedScale

public NumberContext withDecrementedScale()

withDecrementedScale

public NumberContext withDecrementedScale(int subtrahend)

withDoubledPrecision

public NumberContext withDoubledPrecision()

withDoubledScale

public NumberContext withDoubledScale()

withFormat

public NumberContext withFormat(NumberStyle style,
 Locale locale)

withHalvedPrecision

public NumberContext withHalvedPrecision()

withHalvedScale

public NumberContext withHalvedScale()

withIncrementedPrecision

public NumberContext withIncrementedPrecision()

withIncrementedPrecision

public NumberContext withIncrementedPrecision(int addend)

withIncrementedScale

public NumberContext withIncrementedScale()

withIncrementedScale

public NumberContext withIncrementedScale(int addend)

withMath

public NumberContext withMath(MathContext math)

withMode

public NumberContext withMode(RoundingMode mode)

withoutPrecision

public NumberContext withoutPrecision()

withoutScale

public NumberContext withoutScale()

withPrecision

public NumberContext withPrecision(int precision)

withScale

public NumberContext withScale(int scale)

scale

private BigDecimal scale(BigDecimal number)

configureFormat

protected void configureFormat(Format format,
 Object object)

Specified by:

configureFormat in class FormatContext<Comparable<?>>

handleFormatException

protected String handleFormatException(Format format,
 Object object)

Specified by:

handleFormatException in class FormatContext<Comparable<?>>

handleParseException

protected Comparable<?> handleParseException(Format format,
 String string)

Specified by:

handleParseException in class FormatContext<Comparable<?>>