## net.sf.saxon.value
Class DoubleValue

    java.lang.Object
      net.sf.saxon.value.Value
          net.sf.saxon.value.AtomicValue
              net.sf.saxon.value.NumericValue
                  net.sf.saxon.value.DoubleValue

All Implemented Interfaces:
  Serializable, Comparable, PullEvent, SequenceIterable, GroundedValue, Item, ValueRepresentation, ConversionResult

    public final class DoubleValue

extends NumericValue

A numeric (double precision floating point) value

See Also:
  Serialized Form

Field Summary
`static DoubleValue` `NaN`
`static DoubleValue` `NEGATIVE_ZERO`
`static DoubleValue` `ONE`
`static DoubleValue` `ZERO`

Fields inherited from class net.sf.saxon.value.AtomicValue
`typeLabel`

Fields inherited from class net.sf.saxon.value.Value
`INDETERMINATE_ORDERING`

Fields inherited from interface net.sf.saxon.om.ValueRepresentation
`EMPTY_VALUE_ARRAY`

Constructor Summary
`DoubleValue(double value)` Constructor supplying a double
`DoubleValue(double value, AtomicType type)` Constructor supplying a double and an AtomicType, for creating a value that belongs to a user-defined subtype of xs:double.

Method Summary
`NumericValue` `abs()` Get the absolute value as defined by the XPath abs() function
`NumericValue` `ceiling()` Implement the XPath ceiling() function
`int` `compareTo(long other)` Compare the value to a long.
`ConversionResult` `convertPrimitive(BuiltInAtomicType requiredType, boolean validate, ConversionRules rules)` Convert to target data type
`AtomicValue` `copyAsSubType(AtomicType typeLabel)` Create a copy of this atomic value, with a different type label
`static CharSequence` `doubleToString(double value)` Internal method used for conversion of a double to a string
`boolean` `effectiveBooleanValue()` Get the effective boolean value
`NumericValue` `floor()` Implement the XPath floor() function
`static DoubleValue` `fromInternalForm(String hex)`
`CharSequence` `getCanonicalLexicalRepresentation()` Get the canonical lexical representation as defined in XML Schema.
`double` `getDoubleValue()` Return this numeric value as a double
`CharSequence` `getPrimitiveStringValue()` Convert the double to a string according to the XPath 2.0 rules
`BuiltInAtomicType` `getPrimitiveType()` Determine the primitive type of the value.
`Comparable` `getSchemaComparable()` Get an object that implements XML Schema comparison semantics
`int` `hashCode()` Get the hashCode.
`boolean` `isIdentical(Value v)` Determine whether two atomic values are identical, as determined by XML Schema rules.
`boolean` `isNaN()` Test whether the value is the double/float value NaN
`boolean` `isWholeNumber()` Determine whether the value is a whole number, that is, whether it compares equal to some integer
`static void` `main(String[] args)`
`NumericValue` `negate()` Negate the value
`static void` `printInternalForm(double d)` Diagnostic method: print the sign, exponent, and significand
`NumericValue` `round(int scale)` Implement the XPath round() function
`NumericValue` `roundHalfToEven(int scale)` Implement the XPath round-to-half-even() function
`double` `signum()` Determine whether the value is negative, zero, or positive

Methods inherited from class net.sf.saxon.value.NumericValue
`compareTo, equals, getDecimalValue, getFloatValue, getXPathComparable, isInteger, longValue, parseNumber, toString`

Methods inherited from class net.sf.saxon.value.AtomicValue
`asAtomic, checkPermittedContents, convert, convert, convert, getCardinality, getComponent, getItemType, getLength, getStringValue, getStringValueCS, getTypedValue, getTypeLabel, itemAt, iterate, process, setTypeLabel, subsequence`

Methods inherited from class net.sf.saxon.value.Value
`asItem, asItem, asIterator, asValue, convertToJava, fromItem, getIterator, iterate, reduce`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Field Detail

### ZERO

    public static final DoubleValue ZERO

### NEGATIVE_ZERO

    public static final DoubleValue NEGATIVE_ZERO

### ONE

    public static final DoubleValue ONE

### NaN

    public static final DoubleValue NaN

Constructor Detail

### DoubleValue

    public DoubleValue(double value)

  Constructor supplying a double

  Parameters:
    `value` - the value of the NumericValue

### DoubleValue

    public DoubleValue(double value,
                       AtomicType type)

  Constructor supplying a double and an AtomicType, for creating a value that belongs to a user-defined subtype of xs:double. It is the caller's responsibility to ensure that the supplied value conforms to the supplied type.

  Parameters:
    `value` - the value of the NumericValue
    `type` - the type of the value. This must be a subtype of xs:double, and the value must conform to this type. The methosd does not check these conditions.

Method Detail

### copyAsSubType

    public AtomicValue copyAsSubType(AtomicType typeLabel)

  Create a copy of this atomic value, with a different type label

  Specified by:
    `copyAsSubType` in class `AtomicValue`
  Parameters:
    `typeLabel` - the type label of the new copy. The caller is responsible for checking that the value actually conforms to this type.
  Returns:
    the copied value

### getPrimitiveType

    public BuiltInAtomicType getPrimitiveType()

  Determine the primitive type of the value. This delivers the same answer as getItemType().getPrimitiveItemType(). The primitive types are the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration, and xs:untypedAtomic. For external objects, the result is AnyAtomicType.

  Specified by:
    `getPrimitiveType` in class `AtomicValue`
  Returns:
    the primitive type

### getDoubleValue

    public double getDoubleValue()

  Return this numeric value as a double

  Overrides:
    `getDoubleValue` in class `NumericValue`
  Returns:
    the value as a double

### hashCode

    public int hashCode()

  Get the hashCode. This must conform to the rules for other NumericValue hashcodes

  Specified by:
    `hashCode` in class `NumericValue`
  Returns:
    the hash code of the numeric value
  See Also:
    `NumericValue.hashCode()`

### isNaN

    public boolean isNaN()

  Test whether the value is the double/float value NaN

  Overrides:
    `isNaN` in class `AtomicValue`
  Returns:
    true if the value is float NaN or double NaN or precisionDecimal NaN; otherwise false

### effectiveBooleanValue

    public boolean effectiveBooleanValue()

  Get the effective boolean value

  Overrides:
    `effectiveBooleanValue` in class `AtomicValue`
  Returns:
    the effective boolean value (true unless the value is zero or NaN)

### convertPrimitive

    public ConversionResult convertPrimitive(BuiltInAtomicType requiredType,
                                             boolean validate,
                                             ConversionRules rules)

  Convert to target data type

  Specified by:
    `convertPrimitive` in class `AtomicValue`
  Parameters:
    `requiredType` - an integer identifying the required atomic type
    `validate` - true if the supplied value must be validated, false if the caller warrants that it is valid
    `rules` -
  Returns:
    an AtomicValue, a value of the required type

### getPrimitiveStringValue

    public CharSequence getPrimitiveStringValue()

  Convert the double to a string according to the XPath 2.0 rules

  Specified by:
    `getPrimitiveStringValue` in class `AtomicValue`
  Returns:
    the string value

### getCanonicalLexicalRepresentation

    public CharSequence getCanonicalLexicalRepresentation()

  Get the canonical lexical representation as defined in XML Schema. This is not always the same as the result of casting to a string according to the XPath rules. For xs:double, the canonical representation always uses exponential notation.

  Overrides:
    `getCanonicalLexicalRepresentation` in class `Value`
  Returns:
    the canonical lexical representation if defined in XML Schema; otherwise, the result of casting to string according to the XPath 2.0 rules

### doubleToString

    public static CharSequence doubleToString(double value)

  Internal method used for conversion of a double to a string

  Parameters:
    `value` - the actual value
  Returns:
    the value converted to a string, according to the XPath casting rules.

### negate

    public NumericValue negate()

  Negate the value

  Specified by:
    `negate` in class `NumericValue`
  Returns:
    a value, of the same type as the original, with its sign inverted

### floor

    public NumericValue floor()

  Implement the XPath floor() function

  Specified by:
    `floor` in class `NumericValue`
  Returns:
    a value, of the same type as that supplied, rounded towards minus infinity

### ceiling

    public NumericValue ceiling()

  Implement the XPath ceiling() function

  Specified by:
    `ceiling` in class `NumericValue`
  Returns:
    a value, of the same type as that supplied, rounded towards plus infinity

### round

    public NumericValue round(int scale)

  Implement the XPath round() function

  Specified by:
    `round` in class `NumericValue`
  Returns:
    a value, of the same type as that supplied, rounded towards the nearest whole number (0.5 rounded up)

### roundHalfToEven

    public NumericValue roundHalfToEven(int scale)

  Implement the XPath round-to-half-even() function

  Specified by:
    `roundHalfToEven` in class `NumericValue`
  Parameters:
    `scale` - the decimal position for rounding: e.g. 2 rounds to a multiple of 0.01, while -2 rounds to a multiple of 100
  Returns:
    a value, of the same type as the original, rounded towards the nearest multiple of 10**(-scale), with rounding towards the nearest even number if two values are equally near

### signum

    public double signum()

  Determine whether the value is negative, zero, or positive

  Specified by:
    `signum` in class `NumericValue`
  Returns:
    -1 if negative, 0 if zero (including negative zero), +1 if positive, NaN if NaN

### isWholeNumber

    public boolean isWholeNumber()

  Determine whether the value is a whole number, that is, whether it compares equal to some integer

  Specified by:
    `isWholeNumber` in class `NumericValue`
  Returns:
    true if the value is a whole number

### abs

    public NumericValue abs()

  Get the absolute value as defined by the XPath abs() function

  Specified by:
    `abs` in class `NumericValue`
  Returns:
    the absolute value
  Since:
    9.2

### compareTo

    public int compareTo(long other)

  Compare the value to a long.

  Specified by:
    `compareTo` in class `NumericValue`
  Parameters:
    `other` - the value to be compared with
  Returns:
    -1 if this is less, 0 if this is equal, +1 if this is greater or if this is NaN

### getSchemaComparable

    public Comparable getSchemaComparable()

  Get an object that implements XML Schema comparison semantics

  Specified by:
    `getSchemaComparable` in class `AtomicValue`
  Returns:
    a Comparable that follows XML Schema comparison rules

### isIdentical

    public boolean isIdentical(Value v)

  Determine whether two atomic values are identical, as determined by XML Schema rules. This is a stronger test than equality (even schema-equality); for example two dateTime values are not identical unless they are in the same timezone.

  Note that even this check ignores the type annotation of the value. The integer 3 and the short 3 are considered identical, even though they are not fully interchangeable. "Identical" means the same point in the value space, regardless of type annotation.

  NaN is identical to itself.

  Overrides:
    `isIdentical` in class `AtomicValue`
  Parameters:
    `v` - the other value to be compared with this one
  Returns:
    true if the two values are identical, false otherwise.

### printInternalForm

    public static void printInternalForm(double d)

  Diagnostic method: print the sign, exponent, and significand

  Parameters:
    `d` - the double to be diagnosed

### fromInternalForm

    public static DoubleValue fromInternalForm(String hex)

### main

    public static void main(String[] args)

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.