Package uk.ac.starlink.ttools.plot2.geom

Class Rotation

java.lang.Object
uk.ac.starlink.ttools.plot2.geom.Rotation
@Equality public abstract class Rotation extends Object
Rotates vectors between sky systems.
Since:
20 Apr 2016
Author:
Mark Taylor

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static Rotation
    IDENTITY
    Identity rotation; the rotate method is a no-op.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    Rotation()
    Protected no-arg constructor of abstract class.

  • Method Summary

    Modifier and Type
    Method
    Description
    static Rotation
    createRotation(SkySys inSys, SkySys outSys)
    Returns a rotation instance that can transform between two submitted sky systems.
    abstract double[]
    getMatrix()
    Returns the 9-element matrix defining this rotation.
    abstract Rotation
    invert()
    Returns the inverse of this rotation.
    static boolean
    isIdentityRotation(SkySys inSys, SkySys outSys)
    Indicates whether the rotation between two sky systems is known to be an identity (no-op) transformation.
    abstract void
    rotate(double[] r3)
    Rotates a 3-vector in place.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • IDENTITY

      public static Rotation IDENTITY
      Identity rotation; the rotate method is a no-op.

  • Constructor Details

    • Rotation

      protected Rotation()
      Protected no-arg constructor of abstract class.

  • Method Details

    • rotate

      public abstract void rotate(double[] r3)
      Rotates a 3-vector in place.
      Parameters:
      r3 - 3-element unit vector, changed on output

    • invert

      public abstract Rotation invert()
      Returns the inverse of this rotation.
      Returns:
      inverse rotation

    • getMatrix

      public abstract double[] getMatrix()
      Returns the 9-element matrix defining this rotation.
      Returns:
      9-element rotation matrix

    • isIdentityRotation

      public static boolean isIdentityRotation(SkySys inSys, SkySys outSys)
      Indicates whether the rotation between two sky systems is known to be an identity (no-op) transformation. If either or both sky systems is null, it is assumed that no rotation is required.
      Parameters:
      inSys - input sky system; may be null
      outSys - output sky system; may be null
      Returns:
      true iff no rotation operation is required

    • createRotation

      public static Rotation createRotation(SkySys inSys, SkySys outSys)
      Returns a rotation instance that can transform between two submitted sky systems.
      Parameters:
      inSys - input sky system; may be null
      outSys - output sky system; may be null
      Returns:
      rotation from input to output sky systems, not null