Class BoxFunction

All Implemented Interfaces:
ADQLObject, ADQLOperand

public class BoxFunction extends GeometryFunction
It represents the box function of the ADQL language.

The BOX function expresses a box on the sky. A BOX is a special case of POLYGON, defined purely for convenience, and it corresponds semantically to the equivalent term, Box, defined in the STC specification.

It is specified by a center position and size (in both axes) defining a cross centered on the center position and with arms extending, parallel to the coordinate axes at the center position, for half the respective sizes on either side. The box’s sides are line segments or great circles intersecting the arms of the cross in its end points at right angles with the arms.

The function arguments specify the center position and the width and height, where:

  • the center position is given by a pair of numeric coordinates in degrees, or a single geometric POINT
  • the width and height are given by numeric values in degrees
  • the center position and the width and height MUST be within the ranges resp. [0,360] and [-90,90].

Example:

A BOX of ten degrees centered on a position (25.4, -20.0) in degrees could be written as follows:

BOX(25.4, -20.0, 10.0, 10.0)

Alternatively, the center position could be expressed as a POINT:

BOX(POINT(25.4, -20.0), 10, 10)

The function arguments may be literal values, as above, or they may be column references, functions or expressions that returns a POINT value.

Example:

BOX(t1.center, t1.width, t1.height)

, where t1.center, t1.width and t1.height are references to database columns that contain POINT, DOUBLE and DOUBLE values respectively.

For historical reasons, the BOX function accepts an optional string value as the first argument. As of this version of the specification (2.1) this parameter has been marked as deprecated. Future versions of this specification (> 2.1) may remove this parameter.

  • Field Details

    • FEATURE

      public static final LanguageFeature FEATURE
      Description of this ADQL Feature.
      Since:
      2.0
  • Constructor Details

  • Method Details

    • getFeatureDescription

      public final LanguageFeature getFeatureDescription()
      Description copied from interface: ADQLObject
      Get the description of this ADQL's Language Feature.

      Note: Getting this description is generally only useful when discovery optional features so that determining if they are allowed to be used in ADQL queries.

      Returns:
      Description of this ADQL object as an ADQL's feature.
    • getCopy

      public ADQLObject getCopy() throws Exception
      Description copied from interface: ADQLObject
      Gets a (deep) copy of this ADQL object.
      Returns:
      The copy of this ADQL object.
      Throws:
      Exception - If there is any error during the copy.
    • getName

      public String getName()
      Description copied from interface: ADQLObject
      Gets the name of this object in ADQL.
      Returns:
      The name of this ADQL object.
    • isNumeric

      public boolean isNumeric()
      Description copied from interface: ADQLOperand
      Tell whether this operand is numeric or not.
      Returns:
      true if this operand is numeric, false otherwise.
    • isString

      public boolean isString()
      Description copied from interface: ADQLOperand
      Tell whether this operand is a string or not.
      Returns:
      true if this operand is a string, false otherwise.
    • isGeometry

      public boolean isGeometry()
      Description copied from interface: ADQLOperand
      Tell whether this operand is a geometrical region or not.
      Returns:
      true if this operand is a geometry, false otherwise.
    • getCenter

      Gets the center point, exactly as provided.

      IMPORTANT NOTE: If this BoxFunction has been initialized with a pair of coordinates, this function will return NULL.

      Returns:
      The center point of the represented box, or NULL if created with a pair of coordinates.
      Since:
      2.0
    • setCenter

      public final void setCenter(GeometryFunction.GeometryValue<GeometryFunction> newCenter)
      Sets the center point.

      WARNING: Calling this function will erase the single coordinates already set: getCoord1() and getCoord2() will both return NULL.

      Parameters:
      newCenter - The new center point of the represented box.
      Since:
      2.0
    • getCoord1

      public final ADQLOperand getCoord1()
      Gets the first coordinate (i.e. right ascension).
      Returns:
      The first coordinate.
    • setCoord1

      public final void setCoord1(ADQLOperand coord1)
      Sets the first coordinate (i.e. right ascension).
      Parameters:
      coord1 - The first coordinate.
    • getCoord2

      public final ADQLOperand getCoord2()
      Gets the second coordinate (i.e. declination).
      Returns:
      The second coordinate.
    • setCoord2

      public final void setCoord2(ADQLOperand coord2)
      Sets the second coordinate (i.e. declination).
      Parameters:
      coord2 - The second coordinate.
    • getWidth

      public final ADQLOperand getWidth()
      Gets the width of the box.
      Returns:
      The width.
    • setWidth

      public final void setWidth(ADQLOperand width)
      Sets the width of the box.
      Parameters:
      width - The width.
    • getHeight

      public final ADQLOperand getHeight()
      Gets the height of the box.
      Returns:
      The height.
    • setHeight

      public final void setHeight(ADQLOperand height)
      Sets the height of the box.
      Parameters:
      height - The height.
    • getParameters

      public ADQLOperand[] getParameters()
      Description copied from class: ADQLFunction
      Gets the list of all parameters of this function.
      Specified by:
      getParameters in class ADQLFunction
      Returns:
      Its parameters list.
    • getNbParameters

      public int getNbParameters()
      Description copied from class: ADQLFunction
      Gets the number of parameters this function has.
      Specified by:
      getNbParameters in class ADQLFunction
      Returns:
      Number of parameters.
    • getParameter

      public ADQLOperand getParameter(int index) throws ArrayIndexOutOfBoundsException
      Description copied from class: ADQLFunction
      Gets the index-th parameter.
      Specified by:
      getParameter in class ADQLFunction
      Parameters:
      index - Parameter number.
      Returns:
      The corresponding parameter.
      Throws:
      ArrayIndexOutOfBoundsException - If the index is incorrect (index invalid input: '<' 0 || index >= getNbParameters()).
    • setParameter

      public ADQLOperand setParameter(int index, ADQLOperand replacer) throws ArrayIndexOutOfBoundsException, NullPointerException, Exception
      Description copied from class: ADQLFunction
      Replaces the index-th parameter by the given one.
      Specified by:
      setParameter in class ADQLFunction
      Parameters:
      index - Index of the parameter to replace.
      replacer - The replacer.
      Returns:
      The replaced parameter.
      Throws:
      ArrayIndexOutOfBoundsException - If the index is incorrect (index invalid input: '<' 0 || index >= getNbParameters()).
      NullPointerException - If a required parameter must be replaced by a NULL object.
      Exception - If another error occurs.