Class TangentPlaneTransformer

java.lang.Object
uk.ac.starlink.ttools.plot2.layer.TangentPlaneTransformer

public class TangentPlaneTransformer extends Object
Performs normalised 3D coordinate transformations equivalent to displacements from the origin in the tangent plane.

This object can deal with the data->view transformation represented by a SkyDataGeom. The input tangent position is in view coordinates, but the input displacements on that plane correspond to displacements along the axes of data coordinates. That may seem baroque, but it corresponds to what sky-based MultiPointCoordSet implementations are likely to be able to supply.

Since:
21 Feb 2013
Author:
Mark Taylor
  • Constructor Summary

    Constructors
    Constructor
    Description
    TangentPlaneTransformer(double[] xyz0, SkyDataGeom geom)
    Constructs a transformer for the tangent plane centred at a given normalised vector.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    displace(double xi, double eta, double[] xyz1)
    Determines the normalised 3D position in view coordinates of a position at given coordinates in this object's tangent plane.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • TangentPlaneTransformer

      public TangentPlaneTransformer(double[] xyz0, SkyDataGeom geom)
      Constructs a transformer for the tangent plane centred at a given normalised vector.
      Parameters:
      xyz0 - normalised 3D coordinates in the view coordinate system at the centre of tangent plane
      geom - geom object representing data->view coordinate system rotation
  • Method Details

    • displace

      public void displace(double xi, double eta, double[] xyz1)
      Determines the normalised 3D position in view coordinates of a position at given coordinates in this object's tangent plane.
      Parameters:
      xi - horizontal displacement in data coordinates from tangent plane origin (tangent point)
      eta - vertical displacement in data coordinates from tangent plane origin (tangent point)
      xyz1 - 3-element array into which normalised 3D coordinates of result position in view coordinates are written