Class CircleFunction

All Implemented Interfaces:
ADQLObject, ADQLOperand

public class CircleFunction extends GeometryFunction
It represents the CIRCLE function of the ADQL language.

This function expresses a circular region on the sky (a cone in space) and it corresponds semantically to the equivalent term, Circle, defined in the STC specification.

The function arguments specify the center position and the radius, where:

  • the center position is given by a pair of numeric coordinates in degrees, or a single geometric POINT
  • the radius is a numeric value in degrees
  • the center position and the radius MUST be within the ranges [0,360] and [-90,90]

Example:

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

CIRCLE(25.4, -20.0, 10.0)

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

CIRCLE(POINT(25.4, -20.0), 10.0)

The position argument may be a literal value, as above, or it may be a column reference, function or expression that returns a POINT value.

Example:

CIRCLE(t1.center, t1.radius)

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

For historical reasons, the CIRCLE 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

    • CircleFunction

      public CircleFunction(ADQLOperand coordinateSystem, ADQLOperand firstCoord, ADQLOperand secondCoord, ADQLOperand radius) throws NullPointerException, Exception
      Builds a CIRCLE function.
      Parameters:
      coordinateSystem - The coordinate system in which the center position is expressed.
      firstCoord - The first coordinate of the center position.
      secondCoord - The second coordinate of the center position.
      radius - The radius of the circle (in degrees).
      Throws:
      NullPointerException - If at least one parameter is incorrect or if the coordinate system is unknown.
      Exception - If there is another error.
    • CircleFunction

      public CircleFunction(ADQLOperand coordinateSystem, GeometryFunction.GeometryValue<GeometryFunction> center, ADQLOperand radius) throws NullPointerException, Exception
      Builds a CIRCLE function.
      Parameters:
      coordinateSystem - The coordinate system in which the center position is expressed.
      center - The center position.
      radius - The radius of the circle (in degrees).
      Throws:
      NullPointerException - If at least one parameter is incorrect or if the coordinate system is unknown.
      Exception - If there is another error.
      Since:
      2.0
    • CircleFunction

      public CircleFunction(CircleFunction toCopy) throws Exception
      Builds a CIRCLE function by copying the given one.
      Parameters:
      toCopy - The CIRCLE function to copy.
      Throws:
      Exception - If there is an error during the copy.
  • 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 CircleFunction has been initialized with a pair of coordinates, this function will return NULL.

      Returns:
      The center point of the represented circle, 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 circle.
      Since:
      2.0
    • getCoord1

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

      public final void setCoord1(ADQLOperand coord1)
      Sets the first coordinate of the center (i.e. right ascension).

      WARNING: Calling this function will erase the center point already set: getCenter() will return NULL.

      Parameters:
      coord1 - The first coordinate.
    • getCoord2

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

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

      public final ADQLOperand getRadius()
      Gets the radius of the center.
      Returns:
      The radius.
    • setRadius

      public final void setRadius(ADQLOperand radius)
      Sets the radius of the center.
      Parameters:
      radius - The radius.
    • 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 < 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 < 0 || index >= getNbParameters()).
      NullPointerException - If a required parameter must be replaced by a NULL object.
      Exception - If another error occurs.