Class TangentPlaneTransformer
java.lang.Object
uk.ac.starlink.ttools.plot2.layer.TangentPlaneTransformer
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
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Constructor Summary
ConstructorsConstructorDescriptionTangentPlaneTransformer
(double[] xyz0, SkyDataGeom geom) Constructs a transformer for the tangent plane centred at a given normalised vector. -
Method Summary
Modifier and TypeMethodDescriptionvoid
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.
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Constructor Details
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TangentPlaneTransformer
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 planegeom
- geom object representing data->view coordinate system rotation
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Method Details
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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
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