casacore::TabularCoordinate Class Reference

Table lookup 1-D coordinate, with interpolation. More...

#include <TabularCoordinate.h>

Inheritance diagram for casacore::TabularCoordinate:

Public Member Functions
	TabularCoordinate ()
	Default constructor.
	TabularCoordinate (Double refval, Double inc, Double refpix, const String &unit, const String &axisName)
	Create a linear TabularCoordinate where `world = refval + inc*(pixel-refpix)`.
	TabularCoordinate (const Quantum< Double > &refval, const Quantum< Double > &inc, Double refpix, const String &axisName)
	Create a linear TabularCoordinate with a Quantum-based interface where `world = refval + inc*(pixel-refpix)`.
	TabularCoordinate (const Vector< Double > &pixelValues, const Vector< Double > &worldValues, const String &unit, const String &axisName)
	Construct a TabularCoordinate with the specified world values.
	TabularCoordinate (const Vector< Double > &pixelValues, const Quantum< Vector< Double > > &worldValues, const String &axisName)
	Construct a TabularCoordinate with the specified world values via the Quantum-based interface.
	TabularCoordinate (const TabularCoordinate &other)
	Copy constructor (copy semantics).
TabularCoordinate &	operator= (const TabularCoordinate &other)
	Assignment (copy semantics).
virtual	~TabularCoordinate ()
	Destructor.
virtual Coordinate::Type	type () const
	Returns Coordinate::TABULAR.
virtual String	showType () const
	Always returns the String "Tabular".
virtual uInt	nPixelAxes () const
	Always returns 1.
virtual uInt	nWorldAxes () const
virtual Bool	toWorld (Vector< Double > &world, const Vector< Double > &pixel, Bool=True) const
	Convert a pixel position to a world position or vice versa.
virtual Bool	toPixel (Vector< Double > &pixel, const Vector< Double > &world) const
Bool	toWorld (Double &world, Double pixel) const
Bool	toPixel (Double &pixel, Double world) const
virtual Bool	toWorldMany (Matrix< Double > &world, const Matrix< Double > &pixel, Vector< Bool > &failures) const
	Batch up a lot of transformations.
virtual Bool	toPixelMany (Matrix< Double > &pixel, const Matrix< Double > &world, Vector< Bool > &failures) const
virtual void	makePixelRelative (Vector< Double > &pixel) const
	Make absolute coordinates relative and vice-versa (with respect to the referencfe value).
virtual void	makePixelAbsolute (Vector< Double > &pixel) const
virtual void	makeWorldRelative (Vector< Double > &world) const
virtual void	makeWorldAbsolute (Vector< Double > &world) const
virtual Vector< String >	worldAxisNames () const
	Return the requested attribute.
virtual Vector< Double >	referencePixel () const
virtual Matrix< Double >	linearTransform () const
virtual Vector< Double >	increment () const
virtual Vector< Double >	referenceValue () const
virtual Bool	setWorldAxisNames (const Vector< String > &names)
	Set the value of the requested attribute.
virtual Bool	setReferencePixel (const Vector< Double > &refPix)
virtual Bool	setLinearTransform (const Matrix< Double > &xform)
virtual Bool	setIncrement (const Vector< Double > &inc)
virtual Bool	setReferenceValue (const Vector< Double > &refval)
virtual Bool	setWorldAxisUnits (const Vector< String > &units)
	Set/get the axis unit.
virtual Vector< String >	worldAxisUnits () const
Bool	overwriteWorldAxisUnits (const Vector< String > &units)
	Overwrite the world axis units with no compatibility checks or adjustment.
Vector< Double >	pixelValues () const
	Get the table, i.e.
Vector< Double >	worldValues () const
virtual Bool	near (const Coordinate &other, Double tol=1e-6) const
	Comparison function.
virtual Bool	near (const Coordinate &other, const Vector< Int > &excludeAxes, Double tol=1e-6) const
virtual Coordinate *	makeFourierCoordinate (const Vector< Bool > &axes, const Vector< Int > &shape) const
	Find the Coordinate for when we Fourier Transform ourselves.
virtual Bool	save (RecordInterface &container, const String &fieldName) const
	Save the TabularCoordinate into the supplied record using the supplied field name.
virtual Coordinate *	clone () const
	Make a copy of the TabularCoordinate using new.
Static Public Member Functions
static TabularCoordinate *	restore (const RecordInterface &container, const String &fieldName)
	Recover the TabularCoordinate from a record.
Private Member Functions
void	clear_self ()
	Common for assignment operator and destructor.
void	copy (const TabularCoordinate &other)
	Common code for copy ctor and assignment operator.
void	makeNonLinearTabularCoordinate (const Vector< Double > &pixelValues, const Vector< Double > &worldValues)
Private Attributes
Double	crval_p
Double	cdelt_p
Double	crpix_p
Double	matrix_p
String	unit_p
String	name_p
Interpolate1D< Double, Double > *	channel_corrector_p
	Channel_True = channel_corrections_p(Channel_average).
Interpolate1D< Double, Double > *	channel_corrector_rev_p

Detailed Description

Table lookup 1-D coordinate, with interpolation.

Intended use:

Public interface

Review Status

Reviewed By:: Peter Barnes
Date Reviewed:: 1999/12/24
Test programs:: tTabularCoordinate

Prerequisite

Coordinate

Synopsis

This class is used where the world and pixel values are determined by a lookup table. For fractional pixel values, a linear interpolation is used. The values returned for, e.g., the increment, are based on the average of the whole table. At present, the values must either increase or decrease monotonically.

Caution: All pixels coordinates are zero relative;

Example

Let's make a non-linear TabularCoordinate and convert a pixel value to world (which will use linear interpolation)

 Vector<Double> pixelValues(3); 
 Vector<Double> worldValues(3); 
 pixelValues(0) = 122.0;
 pixelValues(1) = 300.0;
 pixelValues(2) = 6524.0;
 worldValues(0) = 1.1e6;
 worldValues(1) = 2.1e6;
 worldValues(2) = 2.2e6;
 
 String unit("km");
 String axisName("length");
 
 TabularCoordinate tc(pixelValues, worldValues, unit, axisName);
 
 Double world, pixel;
 pixel = 200.12;
 if (!tc.toWorld(world, pixel)) {
 cerr << "Error : " << tc.errorMessage() << endl;
 } else {
 cerr << "pixel, world = " << pixel << ", " << world << endl;
 }

Motivation

This class was motivated by the need for an irregular axis, such as a collection of frequencies. For example, the SpectralCoordinate class contains a TabularCoordinate.

Thrown Exceptions

AipsError

To Do

Allow interpolations other than linear.

Definition at line 114 of file TabularCoordinate.h.

Constructor & Destructor Documentation

casacore::TabularCoordinate::TabularCoordinate ( )

Default constructor.

It is equivalent to TabularCoordinate(0,1,0, "", "Tabular");

casacore::TabularCoordinate::TabularCoordinate	(	Double	refval,
		Double	inc,
		Double	refpix,
		const String &	unit,
		const String &	axisName
	)

Create a linear TabularCoordinate where world = refval + inc*(pixel-refpix).

casacore::TabularCoordinate::TabularCoordinate	(	const Quantum< Double > &	refval,
		const Quantum< Double > &	inc,
		Double	refpix,
		const String &	axisName
	)

Create a linear TabularCoordinate with a Quantum-based interface where world = refval + inc*(pixel-refpix).

The units of the increment (inc) will be converted to those of the reference value (refVal) which will then serve as the units of the Coordinate.

casacore::TabularCoordinate::TabularCoordinate	(	const Vector< Double > &	pixelValues,
		const Vector< Double > &	worldValues,
		const String &	unit,
		const String &	axisName
	)

Construct a TabularCoordinate with the specified world values.

The increments and related functions return the average values calculated from the first and last world values. The number of pixel and world values must be the same. Normally the pixel values will be 0,1,2,..., but this is not required.

A linear interpolation/extrapolation is used for channels which are not supplied. The reference channel (pixel) is chosen to be 0. The frequencies must increase or decrease monotonically (otherwise the toPixel lookup would not be possible).

casacore::TabularCoordinate::TabularCoordinate	(	const Vector< Double > &	pixelValues,
		const Quantum< Vector< Double > > &	worldValues,
		const String &	axisName
	)

Construct a TabularCoordinate with the specified world values via the Quantum-based interface.

All comments for the previous constructor apply

casacore::TabularCoordinate::TabularCoordinate ( const TabularCoordinate & other )

Copy constructor (copy semantics).

virtual casacore::TabularCoordinate::~TabularCoordinate ( ) [virtual]

Destructor.

Member Function Documentation

void casacore::TabularCoordinate::clear_self ( ) [private]

Common for assignment operator and destructor.

virtual Coordinate* casacore::TabularCoordinate::clone ( ) const [virtual]

Make a copy of the TabularCoordinate using new.

The caller is responsible for calling delete.

virtual Coordinate* casacore::TabularCoordinate::makeFourierCoordinate	(	const Vector< Bool > &	axes,
		const Vector< Int > &	shape
	)			const `[virtual]`

void casacore::TabularCoordinate::makeNonLinearTabularCoordinate	(	const Vector< Double > &	pixelValues,
		const Vector< Double > &	worldValues
	)			`[private]`

virtual Bool casacore::TabularCoordinate::near	(	const Coordinate &	other,
		const Vector< Int > &	excludeAxes,
		Double	tol = `1e-6`
	)			const `[virtual]`

static TabularCoordinate* casacore::TabularCoordinate::restore	(	const RecordInterface &	container,
		const String &	fieldName
	)			`[static]`

virtual Bool casacore::TabularCoordinate::save	(	RecordInterface &	container,
		const String &	fieldName
	)			const `[virtual]`

Bool casacore::TabularCoordinate::toPixel	(	Double &	pixel,
		Double	world
	)			const

virtual Bool casacore::TabularCoordinate::toPixel	(	Vector< Double > &	pixel,
		const Vector< Double > &	world
	)			const `[virtual]`

virtual Bool casacore::TabularCoordinate::toPixelMany	(	Matrix< Double > &	pixel,
		const Matrix< Double > &	world,
		Vector< Bool > &	failures
	)			const `[virtual]`

Bool casacore::TabularCoordinate::toWorld	(	Double &	world,
		Double	pixel
	)			const