Base class for component shapes with two sides. More...

#include <TwoSidedShape.h>

Inheritance diagram for casa::TwoSidedShape:

Public Member Functions
virtual	~TwoSidedShape ()
	a virtual destructor is needed so that the actual destructor in the derived class will be used.
virtual ComponentType::Shape	type () const =0
	return the actual component type.
void	setWidth (const Quantum< Double > &majorAxis, const Quantum< Double > &minorAxis, const Quantum< Double > &positionAngle)
	set/get the width and orientation of the Shape.
void	setWidth (const Quantum< Double > &majorAxis, const Double axialRatio, const Quantum< Double > &positionAngle)
Quantum< Double >	majorAxis () const
Quantum< Double >	minorAxis () const
Quantum< Double >	positionAngle () const
Double	axialRatio () const
void	setErrors (const Quantum< Double > &majorAxisError, const Quantum< Double > &minorAxisError, const Quantum< Double > &positionAngleError)
	set/get the errors on the shape parameters.
const Quantum< Double > &	majorAxisError () const
const Quantum< Double > &	minorAxisError () const
const Quantum< Double > &	positionAngleError () const
Double	axialRatioError () const
virtual void	setWidthInRad (const Double majorAxis, const Double minorAxis, const Double positionAngle)=0
	set/get the width and orientation of the Shape.
virtual Double	majorAxisInRad () const =0
virtual Double	minorAxisInRad () const =0
virtual Double	positionAngleInRad () const =0
virtual Double	sample (const MDirection &direction, const MVAngle &pixelLatSize, const MVAngle &pixelLongSize) const =0
	Calculate the proportion of the flux that is in a pixel of specified size centered in the specified direction.
virtual void	sample (Vector< Double > &scale, const Vector< MDirection::MVType > &directions, const MDirection::Ref &refFrame, const MVAngle &pixelLatSize, const MVAngle &pixelLongSize) const =0
	Same as the previous function except that many directions can be sampled at once.
virtual DComplex	visibility (const Vector< Double > &uvw, const Double &frequency) const =0
	Return the Fourier transform of the component at the specified point in the spatial frequency domain.
virtual void	visibility (Vector< DComplex > &scale, const Matrix< Double > &uvw, const Double &frequency) const =0
	Same as the previous function except that many (u,v,w) points can be sampled at once.
virtual void	visibility (Matrix< DComplex > &scale, const Matrix< Double > &uvw, const Vector< Double > &frequency) const =0
	same as above but with many frequencies
virtual Bool	isSymmetric () const
	determine whether the shape is symmetric or not.
virtual ComponentShape *	clone () const =0
	Return a pointer to a copy of this object upcast to a ComponentShape object.
virtual uInt	nParameters () const
	set/get the shape parameters associated with this shape.
virtual void	setParameters (const Vector< Double > &newParms)
virtual Vector< Double >	parameters () const
virtual void	setErrors (const Vector< Double > &newParms)
virtual Vector< Double >	errors () const
virtual Vector< Double >	optParameters () const
virtual void	setOptParameters (const Vector< Double > &newOptParms)
virtual Bool	fromRecord (String &errorMessage, const RecordInterface &record)
	This functions convert between a Record and a shape derived from this class.
virtual Bool	toRecord (String &errorMessage, RecordInterface &record) const
	Convert the class to an Record representation.
virtual Bool	convertUnit (String &errorMessage, const RecordInterface &record)
	Convert the parameters of the component to the specified units.
virtual Bool	ok () const
	Function which checks the internal data of this class for correct dimensionality and consistent values.
virtual Vector< Double >	toPixel (const DirectionCoordinate &dirCoord) const
	Convert component shape to absolute pixels (longitude, latitude, major axis, minor axis, position angle [positive +x -> +y ; rad])
virtual Bool	fromPixel (const Vector< Double > &parameters, const DirectionCoordinate &dirCoord)
	Fill the shape from the vector (longitude, latitude, major axis, minor axis, position angle [positive +x -> +y ; rad]).
virtual String	sizeToString () const =0
	Get the string containing the various size quantities of a component.
Static Public Member Functions
static String	sizeToString (Quantity major, Quantity minor, Quantity posangle, Bool includeUncertainties=True, Quantity majorErr=0, Quantity minorErr=0, Quantity posanErr=0)
	Format the string containing the various size quantities of a component.
Protected Member Functions
	TwoSidedShape ()
	The constructors and assignment operator are protected as only derived classes should use them.
	TwoSidedShape (const MDirection &direction, const Unit &majorAxisUnit, const Unit &minorAxisUnit, const Unit &paUnit)
	TwoSidedShape (const TwoSidedShape &other)
TwoSidedShape &	operator= (const TwoSidedShape &other)
Private Member Functions
Vector< Double >	widthToCartesian (const Quantum< Double > &width, const Quantum< Double > &pa, const MDirection &dirRef, const DirectionCoordinate &dirCoord, const Vector< Double > &pixelCen) const
MDirection	directionFromCartesian (Double width, Double pa, const DirectionCoordinate &dirCoord, const Vector< Double > &pixelCen) const
Private Attributes
Unit	itsMajUnit

Unit	itsMinUnit
Unit	itsPaUnit
Quantum< Double >	itsMajErr
Quantum< Double >	itsMinErr
Quantum< Double >	itsPaErr

Detailed Description

Base class for component shapes with two sides.

Intended use:

Public interface

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Prerequisite

Synopsis

This base class adds a common interface for component shapes that have two sides. These shapes can be parameterised as having a major-axis width, minor-axis width and a position angle (as well as the reference direction). Currently there are two shapes which use this parameterisation, the Gaussian shape and the disk shape. Shapes which do not have this parameterisation, such as the point shape, are derived directly from the ComponentShape class.

Functions in this class implement a more convenient way of setting the parameters associated with two-sided shapes than the very flexible, but clumsy, parameters functions. The width parameters can be set using the setWidth functions. These functions enforce the rule that the major-axis width must not be smaller than the minor-axis width. Hence the axial ratio, which is the minor-axis width divided by the major-axis width, must always be greater than zero and less than or equal to one.

The functions in this class also free derived classes from the having to deal with units. Any angular unit can be used to specify the width of the shape. The widths returned by the majoraxis, minoraxis & the positionAngle functions are in the same units as they where specified in, unless the convertUnit function has been used to specify another unit.

For maximum speed the *InRad functions are provided. These functions bypass all the computation involving units.

The toRecord and fromRecord functions in this class standardise the record representation of classes derived from this one. In addition to the type and direction fields all records, discussed in the ComponentShape class, there are three more mandatory fields called; majoraxis, minoraxis & positionangle. These fields are record representation of Quantum<Double> objects and hence contain a value and unit. eg., A typical record for any of the shapes derived from this class might be:

    c := [type = 'gaussian',
          direction = [type = 'direction',
                       refer = 'b1950',
                       m0 = [value = .1, unit = 'rad']
                       m1 = [value = -.1, unit = 'rad']
                      ],
          majoraxis = [value=.5, unit='arcmin'],
          minoraxis = [value=1, unit='arcsec'],
          positionangle = [value=10, unit='deg']
         ]

Example

Because this is an abstract base class, an actual instance of this class cannot be constructed. However the interface it defines can be used inside a function. This allows functions which have TwoSidedShapes as arguments to work for any derived class. Hence the printShape function shown below will work for GaussianShapes and DiskShapes but not for PointShapes.

In this example the printShape function prints out the type of model it is working with, the reference direction of that model, the major-axis width, minor-axis width and the position angle. This example is also available in the dTwoSidedShape.cc file.

     void printShape(const TwoSidedShape& theShape) {
       cout << "This is a " << ComponentType::name(theShape.type())
            << " shape " << endl 
            << "with a reference direction of "
            << theShape.refDirection().getAngle("deg") << " ("
            << theShape.refDirection().getRefString() << ")" << endl
            << "and a major axis of " << theShape.majorAxis() << endl
            << "      minor axis of " << theShape.minorAxis() << endl
            << "and   position angle of " << theShape.positionAngle() << endl;
     }

Motivation

This base class was created to allow the reuse of a number of common functions by all derived classes.

To Do

Use Measures & Quanta in the interface to the visibility functions.

Definition at line 152 of file TwoSidedShape.h.

Constructor & Destructor Documentation

virtual casa::TwoSidedShape::~TwoSidedShape ( ) [virtual]

a virtual destructor is needed so that the actual destructor in the derived class will be used.

casa::TwoSidedShape::TwoSidedShape ( ) [protected]

The constructors and assignment operator are protected as only derived classes should use them.

casa::TwoSidedShape::TwoSidedShape	(	const MDirection &	direction,
		const Unit &	majorAxisUnit,
		const Unit &	minorAxisUnit,
		const Unit &	paUnit
	)		`[protected]`

casa::TwoSidedShape::TwoSidedShape ( const TwoSidedShape & other ) [protected]

Member Function Documentation

Double casa::TwoSidedShape::axialRatio ( ) const

Reimplemented in casa::GaussianShape.

Double casa::TwoSidedShape::axialRatioError ( ) const

virtual ComponentShape* casa::TwoSidedShape::clone ( ) const [pure virtual]

Return a pointer to a copy of this object upcast to a ComponentShape object.

The class that uses this function is responsible for deleting the pointer. This is used to implement a virtual copy constructor.

virtual Bool casa::TwoSidedShape::convertUnit	(	String &	errorMessage,
		const RecordInterface &	record
	)		`[virtual]`

MDirection casa::TwoSidedShape::directionFromCartesian	(	Double	width,
		Double	pa,
		const DirectionCoordinate &	dirCoord,
		const Vector< Double > &	pixelCen
	)		const `[private]`

virtual Bool casa::TwoSidedShape::fromPixel	(	const Vector< Double > &	parameters,
		const DirectionCoordinate &	dirCoord
	)		`[virtual]`

virtual Bool casa::TwoSidedShape::fromRecord	(	String &	errorMessage,
		const RecordInterface &	record
	)		`[virtual]`

virtual Double casa::TwoSidedShape::sample	(	const MDirection &	direction,
		const MVAngle &	pixelLatSize,
		const MVAngle &	pixelLongSize
	)		const `[pure virtual]`

virtual void casa::TwoSidedShape::sample	(	Vector< Double > &	scale,
		const Vector< MDirection::MVType > &	directions,
		const MDirection::Ref &	refFrame,
		const MVAngle &	pixelLatSize,
		const MVAngle &	pixelLongSize
	)		const `[pure virtual]`

void casa::TwoSidedShape::setErrors	(	const Quantum< Double > &	majorAxisError,
		const Quantum< Double > &	minorAxisError,
		const Quantum< Double > &	positionAngleError
	)

void casa::TwoSidedShape::setWidth	(	const Quantum< Double > &	majorAxis,
		const Quantum< Double > &	minorAxis,
		const Quantum< Double > &	positionAngle
	)

virtual void casa::TwoSidedShape::setWidthInRad	(	const Double	majorAxis,
		const Double	minorAxis,
		const Double	positionAngle
	)		`[pure virtual]`

static String casa::TwoSidedShape::sizeToString	(	Quantity	major,
		Quantity	minor,
		Quantity	posangle,
		Bool	includeUncertainties = `True`,
		Quantity	majorErr = `0`,
		Quantity	minorErr = `0`,
		Quantity	posanErr = `0`
	)		`[static]`

virtual Bool casa::TwoSidedShape::toRecord	(	String &	error,
		RecordInterface &	outRecord
	)		const `[virtual]`

virtual DComplex casa::TwoSidedShape::visibility	(	const Vector< Double > &	uvw,
		const Double &	frequency
	)		const `[pure virtual]`

virtual void casa::TwoSidedShape::visibility	(	Vector< DComplex > &	scale,
		const Matrix< Double > &	uvw,
		const Double &	frequency
	)		const `[pure virtual]`

virtual void casa::TwoSidedShape::visibility	(	Matrix< DComplex > &	scale,
		const Matrix< Double > &	uvw,
		const Vector< Double > &	frequency
	)		const `[pure virtual]`

Vector<Double> casa::TwoSidedShape::widthToCartesian	(	const Quantum< Double > &	width,
		const Quantum< Double > &	pa,
		const MDirection &	dirRef,
		const DirectionCoordinate &	dirCoord,
		const Vector< Double > &	pixelCen
	)		const `[private]`

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes