casa::WCCoordinateHandler Class Reference

Base class defining a set of transformations for WorldCanvas coordinates. More...

#include <WCCoordinateHandler.h>

Inheritance diagram for casa::WCCoordinateHandler:

List of all members.

Public Member Functions
	WCCoordinateHandler ()
	Default Constructor Required.
virtual Bool	linToWorld (Vector< Double > &world, const Vector< Double > &lin)=0
	transform the lin point (2-dimensional) into a world coordinate (N-dimensional), returning False if the coordinate could not be transformed.
virtual Bool	linToWorld (Matrix< Double > &world, Vector< Bool > &failures, const Matrix< Double > &lin)
	Batch transformation where each row of lin is a coordinate that is transformed into each row of world.
virtual Bool	worldToLin (Vector< Double > &lin, const Vector< Double > &world)=0
	transform the world point (N-dimensional) into a lin coordinate (2-dimensional), returning False if the coordinate could not be transformed.
virtual Bool	worldToLin (Matrix< Double > &lin, Vector< Bool > &failures, const Matrix< Double > &world)
	Batch transformation where each row of world is a coordinate that is transformed into each row of lin.
virtual uInt	nWorldAxes () const =0
	Return the number of axes in the world coordinates.
virtual	~WCCoordinateHandler ()
	Routines that give the axes names and the unit.

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Detailed Description

Base class defining a set of transformations for WorldCanvas coordinates.

Prerequisite

• Understanding of non-linear World Coordinate Systems

Etymology

WCCoordinateHandler : WorldCanvas Coordinate Handler

Synopsis

The WCCoordinateHandler class implements the concept of a coordinate transformation pair that can be plugged in to the WorldCanvas . It is designed for derivation by the programmer and can thereby be arbitrarily implemented.

This class defines an interface between the WorldCanvas, which uses coordinate transformations for various reasons, and the derived class that implements these coordinate transformations.

The designer of the derived class must write the Vector&ltDouble&gt versions of linToWorld and worldToLin as described in detail below. It is also recommended that the Matrix&ltDouble&gt versions of linToWorld and worldToLin be written to maximize efficiency.

Motivation

• Needed to plug in a user-programmable coordinate transformation functions into the world canvas in a convenient way.

• Wanted to bundle these transformations into a class to follow OO methods.

  Example

  DefaultWCCoordinateHandler

Definition at line 79 of file WCCoordinateHandler.h.

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Constructor & Destructor Documentation

casa::WCCoordinateHandler::WCCoordinateHandler

(

)

Default Constructor Required.

virtual casa::WCCoordinateHandler::~WCCoordinateHandler

(

)

[virtual]

Routines that give the axes names and the unit.

Destructor

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Member Function Documentation

virtual Bool casa::WCCoordinateHandler::linToWorld	(	Vector< Double > &	world,
		const Vector< Double > &	lin
	)		[pure virtual]

transform the lin point (2-dimensional) into a world coordinate (N-dimensional), returning False if the coordinate could not be transformed.

Derived classes should override.

Implemented in casa::WorldCanvasHolder, and casa::DefaultWCCoordinateHandler.

virtual Bool casa::WCCoordinateHandler::linToWorld	(	Matrix< Double > &	world,
		Vector< Bool > &	failures,
		const Matrix< Double > &	lin
	)		[virtual]

Batch transformation where each row of lin is a coordinate that is transformed into each row of world.

On input, if the i'th position in the failures vector is true, the i'th transformation is not attempted. If the j'th transformation fails, the j'th position in the failures vector will be set. The return value is True only when the failures vector has no position set to True; This function is implemented in this base class by making repeated calls to the Vector<Double> version of linToWorld.

Reimplemented in casa::WorldCanvasHolder, and casa::DefaultWCCoordinateHandler.

virtual uInt casa::WCCoordinateHandler::nWorldAxes

(

)

const [pure virtual]

Return the number of axes in the world coordinates.

Implemented in casa::WorldCanvasHolder, and casa::DefaultWCCoordinateHandler.

virtual Bool casa::WCCoordinateHandler::worldToLin	(	Vector< Double > &	lin,
		const Vector< Double > &	world
	)		[pure virtual]

transform the world point (N-dimensional) into a lin coordinate (2-dimensional), returning False if the coordinate could not be transformed.

Derived classes should override.

Implemented in casa::WorldCanvasHolder, and casa::DefaultWCCoordinateHandler.

virtual Bool casa::WCCoordinateHandler::worldToLin	(	Matrix< Double > &	lin,
		Vector< Bool > &	failures,
		const Matrix< Double > &	world
	)		[virtual]

Batch transformation where each row of world is a coordinate that is transformed into each row of lin.

On input, if the i'th position in the failures vector is true, the i'th transformation is not attempted. If the j'th transformation fails, the j'th position in the failures vector will be set. The return value is True only when the failures vector has no position set to True; This function is implemented in this base class by making repeated calls to the Vector<Double> version of worldToLin.

Reimplemented in casa::WorldCanvasHolder, and casa::DefaultWCCoordinateHandler.

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The documentation for this class was generated from the following file:

• code/display/DisplayCanvas/WCCoordinateHandler.h