# Class DefaultCoordinateSystemAxis

Object
FormattableObject
AbstractIdentifiedObject
DefaultCoordinateSystemAxis

All Implemented Interfaces:
  `Serializable, Formattable, Deprecable, LenientComparable, Printable, CoordinateSystemAxis, IdentifiedObject`

public class DefaultCoordinateSystemAxis extends AbstractIdentifiedObject implements CoordinateSystemAxis
Coordinate system axis name, direction, unit and range of values.

## Axis names

In some case, the axis name is constrained by ISO 19111 depending on the coordinate reference system type. This constraint works in two directions. For example, the names geodetic latitude and geodetic longitude shall be used to designate the coordinate axis names associated with a `GeographicCRS`. Conversely, these names shall not be used in any other context. See the GeoAPI `CoordinateSystemAxis` javadoc for more information.

## Immutability and thread safety

This class is immutable and thus thread-safe if the property values (not necessarily the map itself) given to the constructor are also immutable. Unless otherwise noted in the javadoc, this condition holds if all components were created using only SIS factories and static constants.

Since:
  0.4
See Also:
  - `AbstractCS`
  - `Unit`
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final String`
  `MAXIMUM_VALUE_KEY`
  Key for the `"maximumValue"` property to be given to the constructor.
  `static final String`
  `MINIMUM_VALUE_KEY`
  Key for the `"minimumValue"` property to be given to the constructor.
  `static final String`
  `RANGE_MEANING_KEY`
  Key for the `"rangeMeaning"` property to be given to the constructor.

  ### Fields inherited from class AbstractIdentifiedObject

  `DEPRECATED_KEY, DOMAINS_KEY, LOCALE_KEY`

  ### Fields inherited from interface IdentifiedObject

  `ALIAS_KEY, IDENTIFIERS_KEY, NAME_KEY, REMARKS_KEY`

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  ``
  `DefaultCoordinateSystemAxis(Map<String,?> properties, String abbreviation, AxisDirection direction, Unit<?> unit)`
  Constructs an axis from a set of properties.
  `protected`
  `DefaultCoordinateSystemAxis(CoordinateSystemAxis axis)`
  Creates a new coordinate system axis with the same values as the specified one.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static DefaultCoordinateSystemAxis`
  `castOrCopy(CoordinateSystemAxis object)`
  Returns a SIS axis implementation with the same values as the given arbitrary implementation.
  `boolean`
  `equals(Object object, ComparisonMode mode)`
  Compares the specified object with this axis for equality.
  `protected String`
  `formatTo(Formatter formatter)`
  Formats this axis as a Well Known Text `Axis[…]` element.
  `String`
  `getAbbreviation()`
  Returns the abbreviation used for this coordinate system axes.
  `AxisDirection`
  `getDirection()`
  Returns the direction of this coordinate system axis.
  `Class<? extends CoordinateSystemAxis>`
  `getInterface()`
  Returns the GeoAPI interface implemented by this class.
  `double`
  `getMaximumValue()`
  Returns the maximum value normally allowed for this axis, in the unit of measure for the axis.
  `double`
  `getMinimumValue()`
  Returns the minimum value normally allowed for this axis, in the unit of measure for the axis.
  `RangeMeaning`
  `getRangeMeaning()`
  Returns the meaning of axis value range specified by the minimum and maximum values.
  `Unit<?>`
  `getUnit()`
  Returns the unit of measure used for this coordinate system axis.
  `boolean`
  `isHeuristicMatchForName(String name)`
  Returns `true` if either the primary name or at least one alias matches the given string according heuristic rules.

  ### Methods inherited from class AbstractIdentifiedObject

  `castOrCopy, equals, formatTo, getAlias, getDescription, getDomains, getIdentifiers, getName, getRemarks, hashCode, isDeprecated`

  ### Methods inherited from class FormattableObject

  `print, toString, toString, toWKT`

  ### Methods inherited from class Object

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

  ### Methods inherited from interface IdentifiedObject

  `getAlias, getIdentifiers, getName, getRemarks, toWKT`

- ## Field Details

  - ### MINIMUM_VALUE_KEY

    public static final String MINIMUM_VALUE_KEY
    Key for the `"minimumValue"` property to be given to the constructor. This is used for setting the value to be returned by `getMinimumValue()`.
    See Also:
      - Constant Field Values

  - ### MAXIMUM_VALUE_KEY

    public static final String MAXIMUM_VALUE_KEY
    Key for the `"maximumValue"` property to be given to the constructor. This is used for setting the value to be returned by `getMaximumValue()`.
    See Also:
      - Constant Field Values

  - ### RANGE_MEANING_KEY

    public static final String RANGE_MEANING_KEY
    Key for the `"rangeMeaning"` property to be given to the constructor. This is used for setting the value to be returned by `getRangeMeaning()`.
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### DefaultCoordinateSystemAxis

    public DefaultCoordinateSystemAxis(Map<String,?> properties, String abbreviation, AxisDirection direction, Unit<?> unit)
    Constructs an axis from a set of properties. The properties given in argument follow the same rules than for the super-class constructor. Additionally, the following properties are understood by this constructor:

    Recognized properties (non exhaustive list)
    Property name | Value type | Returned by
    --- | --- | ---
    "minimumValue" | `Number` | `getMinimumValue()`
    "maximumValue" | `Number` | `getMaximumValue()`
    "rangeMeaning" | `RangeMeaning` | `getRangeMeaning()`
    Defined in parent class (reminder)
    "name" | `ReferenceIdentifier` or `String` | `AbstractIdentifiedObject.getName()`
    "alias" | `GenericName` or `CharSequence` (optionally as array) | `AbstractIdentifiedObject.getAlias()`
    "identifiers" | `ReferenceIdentifier` (optionally as array) | `AbstractIdentifiedObject.getIdentifiers()`
    "remarks" | `InternationalString` or `String` | `AbstractIdentifiedObject.getRemarks()`

    Generally speaking, information provided in the `properties` map are considered ignorable metadata (except the axis name) while information provided as explicit arguments may have an impact on coordinate transformation results. Exceptions to this rule are the `minimumValue` and `maximumValue` in the particular case where `rangeMeaning` is `RangeMeaning​.WRAPAROUND`.

    If no minimum, maximum and range meaning are specified, then this constructor will infer them from the axis unit and direction.

    Parameters:
      `properties` - the properties to be given to the identified object.
      `abbreviation` - the abbreviation used for this coordinate system axis.
      `direction` - the direction of this coordinate system axis.
      `unit` - the unit of measure used for this coordinate system axis.
    See Also:
      - `GeodeticObjectFactory​.createCoordinateSystemAxis(Map, String, AxisDirection, Unit)`

  - ### DefaultCoordinateSystemAxis

    protected DefaultCoordinateSystemAxis(CoordinateSystemAxis axis)
    Creates a new coordinate system axis with the same values as the specified one. This copy constructor provides a way to convert an arbitrary implementation into a SIS one or a user-defined one (as a subclass), usually in order to leverage some implementation-specific API.

    This constructor performs a shallow copy, i.e. the properties are not cloned.

    Parameters:
      `axis` - the coordinate system axis to copy.
    See Also:
      - `castOrCopy(CoordinateSystemAxis)`

- ## Method Details

  - ### castOrCopy

    public static DefaultCoordinateSystemAxis castOrCopy(CoordinateSystemAxis object)
    Returns a SIS axis implementation with the same values as the given arbitrary implementation. If the given object is `null`, then this method returns `null`. Otherwise if the given object is already a SIS implementation, then the given object is returned unchanged. Otherwise a new SIS implementation is created and initialized to the values of the given object.
    Parameters:
      `object` - the object to get as a SIS implementation, or `null` if none.
    Returns:
      a SIS implementation containing the values of the given object (may be the given object itself), or `null` if the argument was null.

  - ### getInterface

    public Class<? extends CoordinateSystemAxis> getInterface()
    Returns the GeoAPI interface implemented by this class. The SIS implementation returns `CoordinateSystemAxis​.class`.

    #### Note for implementers

    Subclasses usually do not need to override this method since GeoAPI does not define `CoordinateSystemAxis` sub-interface. Overriding possibility is left mostly for implementers who wish to extend GeoAPI with their own set of interfaces.
    Overrides:
      `getInterface` in class `AbstractIdentifiedObject`
    Returns:
      `CoordinateSystemAxis​.class` or a user-defined sub-interface.

  - ### getDirection

    public AxisDirection getDirection()
    Returns the direction of this coordinate system axis. This direction is often approximate and intended to provide a human interpretable meaning to the axis. A coordinate system cannot contain two axes having the same direction or opposite directions.

    Examples: north or south, east or west, up or down.

    Specified by:
      `getDirection` in interface `CoordinateSystemAxis`
    Returns:
      the direction of this coordinate system axis.

  - ### getAbbreviation

    public String getAbbreviation()
    Returns the abbreviation used for this coordinate system axes. Examples are X and Y.
    Specified by:
      `getAbbreviation` in interface `CoordinateSystemAxis`
    Returns:
      the coordinate system axis abbreviation.

  - ### getUnit

    public Unit<?> getUnit()
    Returns the unit of measure used for this coordinate system axis. If this `CoordinateSystemAxis` was given by ``CoordinateSystem​.getAxis`(i)`, then all coordinate values at dimension i in a coordinate tuple shall be recorded using this unit of measure.
    Specified by:
      `getUnit` in interface `CoordinateSystemAxis`
    Returns:
      the unit of measure used for coordinate values along this coordinate system axis.

  - ### getMinimumValue

    public double getMinimumValue()
    Returns the minimum value normally allowed for this axis, in the unit of measure for the axis. If there is no minimum value, then this method returns negative infinity.
    Specified by:
      `getMinimumValue` in interface `CoordinateSystemAxis`
    Returns:
      the minimum value normally allowed for this axis.

  - ### getMaximumValue

    public double getMaximumValue()
    Returns the maximum value normally allowed for this axis, in the unit of measure for the axis. If there is no maximum value, then this method returns negative infinity.
    Specified by:
      `getMaximumValue` in interface `CoordinateSystemAxis`
    Returns:
      the maximum value normally allowed for this axis.

  - ### getRangeMeaning

    public RangeMeaning getRangeMeaning()
    Returns the meaning of axis value range specified by the minimum and maximum values. If there is no minimum and maximum values (i.e. if those values are negative infinity and positive infinity respectively), then this method returns `null`.
    Specified by:
      `getRangeMeaning` in interface `CoordinateSystemAxis`
    Returns:
      the meaning of axis value range, or `null` if unspecified.

  - ### isHeuristicMatchForName

    public boolean isHeuristicMatchForName(String name)
    Returns `true` if either the primary name or at least one alias matches the given string according heuristic rules. This method performs the comparison documented in the `super-class`, with an additional flexibility for latitudes and longitudes:
    - `"Lat"`, `"Latitude"` and `"Geodetic latitude"` are considered equivalent.
    - `"Lon"`, `"Longitude"` and `"Geodetic longitude"` are considered equivalent.
    The above special cases are needed in order to workaround a conflict in specifications: ISO 19111 states explicitly that the latitude and longitude axis names shall be Geodetic latitude and Geodetic longitude, while the legacy OGC 01-009 (where version 1 of the WKT format is defined) said that the default values shall be Lat and Lon.

    #### Future evolutions

    This method implements heuristic rules learned from experience while trying to provide inter-operability with different data producers. Those rules may be adjusted in any future SIS version according experience gained while working with more data producers.
    Overrides:
      `isHeuristicMatchForName` in class `AbstractIdentifiedObject`
    Parameters:
      `name` - the name to compare.
    Returns:
      `true` if the primary name of at least one alias matches the specified `name`.
    See Also:
      - `IdentifiedObjects​.isHeuristicMatchForName(IdentifiedObject, String)`
      - `Characters​.Filter​.LETTERS_AND_DIGITS`

  - ### equals

    public boolean equals(Object object, ComparisonMode mode)
    Compares the specified object with this axis for equality. The strictness level is controlled by the second argument. This method compares the following properties in every cases:
    - `AbstractIdentifiedObject​.getName()`
    - `getDirection()`
    - `getUnit()`
    In the particular case where `getRangeMeaning()` is `WRAPAROUND`, then `getMinimumValue()` and `getMaximumValue()` are considered non-ignorable metadata and will be compared for every modes. All other properties are compared only for modes stricter than `ComparisonMode​.IGNORE_METADATA`.
    Specified by:
      `equals` in interface `LenientComparable`
    Overrides:
      `equals` in class `AbstractIdentifiedObject`
    Parameters:
      `object` - the object to compare to `this`.
      `mode` - the strictness level of the comparison.
    Returns:
      `true` if both objects are equal.
    See Also:
      - `AbstractIdentifiedObject​.computeHashCode()`
      - `Utilities​.deepEquals(Object, Object, ComparisonMode)`

  - ### formatTo

    protected String formatTo(Formatter formatter)
    Formats this axis as a Well Known Text `Axis[…]` element.

    #### Constraints for WKT validity

    The ISO 19162 specification puts many constraints on axis names, abbreviations and directions allowed in WKT. Most of those constraints are inherited from ISO 19111 — see `CoordinateSystemAxis` javadoc for some of those. The current Apache SIS implementation does not verify whether this axis name and abbreviation are compliant; we assume that the user created a valid axis. The only actions (derived from ISO 19162 rules) taken by this method (by default) are:
    - Replace Geodetic latitude and Geodetic longitude names (case insensitive) by latitude and longitude respectively.
    - For latitude and longitude axes, replace “φ” and “λ” abbreviations by “B” and “L” respectively (from German “Breite” and “Länge”, used in academic texts worldwide). Note that “L” is also the transliteration of Greek letter “lambda” (λ).
    - In `SphericalCS`, replace “φ” and “θ” abbreviations by “U” and “V” respectively.
    - In `PolarCS`, replace “θ” abbreviation by “U”.
    The above-cited replacements of name and Greek letters can be controlled by a call to `WKTFormat​.setTransliterator(Transliterator)`.
    Overrides:
      `formatTo` in class `AbstractIdentifiedObject`
    Parameters:
      `formatter` - the formatter where to format the inner content of this WKT element.
    Returns:
      `"Axis"`.
    See Also:
      - `FormattableObject​.toWKT()`
      - `FormattableObject​.toString()`