casacore::StokesCoordinate Class Reference

Interconvert between pixel and Stokes value. More...

#include <StokesCoordinate.h>

Inheritance diagram for casacore::StokesCoordinate:

Public Member Functions
	StokesCoordinate (const Vector< Int > &whichStokes)
	The length of whichStokes is the length of the axis, and the values define which stokes are in which axis value.
	StokesCoordinate (const StokesCoordinate &other)
	Copy constructor (copy semantics).
StokesCoordinate &	operator= (const StokesCoordinate &other)
	Assignment (copy semantics).
virtual	~StokesCoordinate ()
	Destructor.
virtual Coordinate::Type	type () const
	Returns Coordinates::STOKES.
virtual String	showType () const
	Always returns the String "Stokes".
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 to a world coordinate or vice versa.
virtual Bool	toPixel (Vector< Double > &pixel, const Vector< Double > &world) const
Bool	toPixel (Int &pixel, Stokes::StokesTypes stokes) const
	Interconvert between pixel and world as a Stokes type.
Bool	toWorld (Stokes::StokesTypes &stokes, Int pixel) const
virtual void	makePixelRelative (Vector< Double > &pixel) const
	Make absolute coordinates relative and vice-versa.
virtual void	makePixelAbsolute (Vector< Double > &pixel) const
virtual void	makeWorldRelative (Vector< Double > &world) const
virtual void	makeWorldAbsolute (Vector< Double > &world) const
Vector< Int >	stokes () const
	Get the Stokes values (Stokes::StokesType) that we constructed with into a vector.
Vector< String >	stokesStrings () const
	Get the stokes string representations.
void	setStokes (const Vector< Int > &whichStokes)
	Set a new vector of Stokes values (a vector of Stokes::StokesType).
virtual Vector< String >	worldAxisNames () const
	Report the value of 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)
	The set function has no effect as the units must be empty for a StokesCoordinate Always returns True.
virtual Vector< String >	worldAxisUnits () const
virtual Bool	setWorldMixRanges (const IPosition &shape)
	Set the world min and max ranges, for use in function `toMix`, for a lattice of the given shape (for this coordinate).
virtual void	setDefaultWorldMixRanges ()
virtual String	format (String &units, Coordinate::formatType format, Double worldValue, uInt worldAxis, Bool isAbsolute=True, Bool showAsAbsolute=True, Int precision=-1, Bool usePrecForMixed=False) const
	Format a StokesCoordinate world value with the common format interface (refer to the base class Coordinate for basics.
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 Bool	save (RecordInterface &container, const String &fieldName) const
	Save the StokesCoordinate into the supplied record using the supplied field name.
virtual Coordinate *	clone () const
	Make a copy of the StokesCoordinate using new.
virtual Bool	doNearPixel (const Coordinate &other, const Vector< Bool > &thisAxes, const Vector< Bool > &otherAxes, Double tol=1.0e-6) const
	Comparison only made for specified axes in this and other Coordinate.
Static Public Member Functions
static Double	toWorld (Stokes::StokesTypes stokes)
	Interconvert between world stored as a Double and world stored as a Stokes type.
static Stokes::StokesTypes	toWorld (Double world)
static StokesCoordinate *	restore (const RecordInterface &container, const String &fieldName)
	Recover the StokesCoordinate from a record.
Private Member Functions
Bool	toWorld (Double &world, const Double pixel) const
Bool	toPixel (Double &pixel, const Double world) const
	StokesCoordinate ()
	Undefined and inaccessible.
Private Attributes
Block< Int >	values_p
Double	crval_p
	Keep these for subimaging purposes.
Double	crpix_p
Double	matrix_p
Double	cdelt_p
String	name_p
String	unit_p
Int	nValues_p

Detailed Description

Interconvert between pixel and Stokes value.

Intended use:

Public interface

Review Status

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

Prerequisite

Synopsis

Although not really a "coordinate", an axis where pixel numbers are used for different Stokes values is in wide use. The StokesCoordinate is a poor fit to the Coordinate polymorphic model. You will probably find that if you try to use the Coordinate classes polymorphically, that StokesCoordinate will cause you to break the polymorphism. I.e. you may have to deal with a specific StokesCoordinate)

The StokesCoordinate just maintains a list (given in the constructor) of possibly non-monotonic Stokes values. The values of the list are the world values (they are values from the Stokes::StokesTypes enum). Thus world = list[pixel] where pixel is the pixel coordinate (0,1, ...)

This means that concepts such as reference pixel, reference value, increment etc are meaningless for StokesCoordinate. You can recover these these attributes, but the functions to set these attributes have no effect.

Note also that for the StokesCoordinate relative world coordinates are defined to be the as absolute, since there is no meaning for a relative Stokes world value (e.g. what is XX -RL ?? Relative pixel coordinates are defined.

Caution: All pixel coordinates are zero relative;

Example

In this example we create a StokesCoordinate housing IQUV

 Vector<Int> iquv(4);
 iquv(0) = Stokes::I; iquv(1) = Stokes::Q;
 iquv(2) = Stokes::U; iquv(3) = Stokes::V;
 StokesCoordinate stokes(iquv);

Motivation

It is conventional to make a pseudo-axis of Stokes parameters. Another approach is to make an image type called Stokes.

To Do

This could probably be generalized into an "enumeration axis" class.

Definition at line 105 of file StokesCoordinate.h.

Constructor & Destructor Documentation

casacore::StokesCoordinate::StokesCoordinate ( const Vector< Int > & whichStokes ) [explicit]

The length of whichStokes is the length of the axis, and the values define which stokes are in which axis value.

Often the vector will be of length 4 and will contain Stokes::I, Q, U and V, however any valid value from the stokes enum may be used. The values may not repeat however, e.g. only one axis position may contain "I".

casacore::StokesCoordinate::StokesCoordinate ( const StokesCoordinate & other )

Copy constructor (copy semantics).

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

Destructor.

casacore::StokesCoordinate::StokesCoordinate ( ) [private]

Undefined and inaccessible.

Member Function Documentation

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

Make a copy of the StokesCoordinate using new.

The caller is responsible for calling delete.

virtual Bool casacore::StokesCoordinate::doNearPixel	(	const Coordinate &	other,
		const Vector< Bool > &	thisAxes,
		const Vector< Bool > &	otherAxes,
		Double	tol = `1.0e-6`
	)			const `[virtual]`

virtual String casacore::StokesCoordinate::format	(	String &	units,
		Coordinate::formatType	format,
		Double	worldValue,
		uInt	worldAxis,
		Bool	isAbsolute = `True`,
		Bool	showAsAbsolute = `True`,
		Int	precision = `-1`,
		Bool	usePrecForMixed = `False`
	)			const `[virtual]`

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

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

Bool casacore::StokesCoordinate::toPixel	(	Double &	pixel,
		const Double	world
	)			const `[private]`

Bool casacore::StokesCoordinate::toPixel	(	Int &	pixel,
		Stokes::StokesTypes	stokes
	)			const

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

Bool casacore::StokesCoordinate::toWorld	(	Double &	world,
		const Double	pixel
	)			const `[private]`

Bool casacore::StokesCoordinate::toWorld	(	Stokes::StokesTypes &	stokes,
		Int	pixel
	)			const

casacore::StokesCoordinate Class Reference

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes