casacore::ImageBeamSet Class Reference

Represents a set of restoring beams associated with an image. More...

#include <ImageBeamSet.h>

Public Types
typedef Array< GaussianBeam > ::const_iterator	BeamIter
Public Member Functions
	ImageBeamSet ()
	Construct an empty beam set.
	ImageBeamSet (const Matrix< GaussianBeam > &beams)
	Construct a beam set from an 2-D array of beams representing the frequency and stokes axis.
	ImageBeamSet (const GaussianBeam &beam)
	construct an ImageBeamSet representing a single beam which is valid for all channels and stokes
	ImageBeamSet (uInt nchan, uInt nstokes, const GaussianBeam &beam=GaussianBeam::NULL_BEAM)
	Create an ImageBeamSet of the specified shape with all GaussianBeams initialized to `beam`.
	ImageBeamSet (const ImageBeamSet &other)
	The copy constructor (reference semantics).
	~ImageBeamSet ()
ImageBeamSet &	operator= (const ImageBeamSet &other)
	Assignment can change the shape (copy semantics).
Bool	operator== (const ImageBeamSet &other) const
	Beam sets are equal if the shapes and all corresponding beams are equal.
Bool	operator!= (const ImageBeamSet &other) const
Bool	equivalent (const ImageBeamSet &that) const
	Beam sets are equivalent if both have no beams or if the expanded sets are equal.
uInt	nelements () const
	Get the number of elements in the beam array.
uInt	size () const
Bool	hasSingleBeam () const
Bool	hasMultiBeam () const
	Does this beam set contain multiple beams?
Bool	empty () const
	Is the beam set empty?
const IPosition &	shape () const
	Get the shape of the beam array.
uInt	nchan () const
	Get the number of channels in the beam array.
uInt	nstokes () const
	Get the number of stokes in the beam array.
const GaussianBeam &	getBeam () const
	Get the single global beam.
const GaussianBeam &	getBeam (Int chan, Int stokes) const
	Get the beam at the specified location.
const GaussianBeam &	operator() (Int chan, Int stokes) const
void	setBeam (Int chan, Int stokes, const GaussianBeam &beam)
	Get a beam at the given 2-dim IPosition.
void	resize (uInt nchan, uInt nstokes)
	Resize the beam array.
ImageBeamSet	subset (const Slicer &imageSlicer, const CoordinateSystem &csys) const
	Return a subset of the beam array.
const Matrix< GaussianBeam > &	getBeams () const
	Get the beam array.
void	setBeams (const Matrix< GaussianBeam > &beams)
	Set the beams in this beam set.
void	set (const GaussianBeam &beam)
	Set all beams to the same value.
GaussianBeam	getMinAreaBeam () const
	Get the beam in the set which has the smallest area.
GaussianBeam	getMaxAreaBeam () const
GaussianBeam	getMedianAreaBeam () const
	Get the beam in the set which has the median area.
IPosition	getMinAreaBeamPosition () const
	Get the position of the beam with the minimum area.
IPosition	getMaxAreaBeamPosition () const
	Get the position of the beam with the maximum area.
const GaussianBeam &	getMinAreaBeamForPol (IPosition &pos, uInt stokes) const
	Get the minimal, maximal, and median area beams and positions in the beam set matrix for the given stokes.
const GaussianBeam &	getMaxAreaBeamForPol (IPosition &pos, uInt stokes) const
const GaussianBeam &	getMedianAreaBeamForPol (IPosition &pos, uInt stokes) const
const GaussianBeam	getSmallestMinorAxisBeam () const
	Get the beam that has the smallest minor axis.
Record	toRecord () const
void	summarize (LogIO &log, Bool verbose, const CoordinateSystem &csys) const
	If verbose, log all beams, if not just summarize beam stats.
void	rotate (const Quantity &angle)
	Modify the beam set by rotating all beams counterclockwise through the specified angle.
Static Public Member Functions
static const String &	className ()
static ImageBeamSet	fromRecord (const Record &rec)
	convert ImageBeamSet to and from record
Private Member Functions
void	_calculateAreas ()
Static Private Member Functions
static void	_chanInfoToStream (ostream &os, const SpectralCoordinate *spCoord, const uInt chan, const uInt chanWidth, const uInt freqPrec, const uInt velWidth, const uInt velPrec)
static void	_beamToStream (ostream &os, const GaussianBeam &beam, const Unit &unit)
Private Attributes
Matrix< GaussianBeam >	_beams
Matrix< Double >	_areas
String	_areaUnit
GaussianBeam	_minBeam
GaussianBeam	_maxBeam
IPosition	_minBeamPos
IPosition	_maxBeamPos
Static Private Attributes
static const String	_DEFAULT_AREA_UNIT

Detailed Description

Represents a set of restoring beams associated with an image.

Intended use:

Public interface

Review Status

Date Reviewed:: yyyy/mm/dd

Etymology

A Set of Beams associated with an Image.

Synopsis

This class represents a set of restoring beams associated with a deconvolved image. Internally, the beams are stored in a Matrix in which the first dimension represents the spectral axis and the second dimension represents the polarization axis. Methods which take the number of channels and stokes as the input parameters will accept 0 for either of these, in the cases where the corresponding axis is absent, but internally, the associated axis of the storage Matrix will be set to one since a Matrix with one dimension of length 0 must be empty. If one (or both) of the axes is of length 1, the beam associated with that position is valid for all channels or stokes at the position. For example, if one has an image with 10 spectral channels and 4 stokes, and one has a beam set of dimensions (1, 4) associated with that image, all channels for a given stokes will have the same beam. Similarly, if the beam set is of shape (10, 1) in this case, all stokes will have the same beam for a given channel. If the axis lengths of the beam set are greater than one, they must be exactly the same length of the corresponding axes in the associated image.

Example

Motivation

Restoring beams are used many places in image analysis tasks.

Definition at line 88 of file ImageBeamSet.h.

Member Typedef Documentation

typedef Array<GaussianBeam>::const_iterator casacore::ImageBeamSet::BeamIter

Definition at line 91 of file ImageBeamSet.h.

Constructor & Destructor Documentation

casacore::ImageBeamSet::ImageBeamSet ( )

Construct an empty beam set.

casacore::ImageBeamSet::ImageBeamSet ( const Matrix< GaussianBeam > & beams )

Construct a beam set from an 2-D array of beams representing the frequency and stokes axis.

Axis length 1 means it is valid for all channels cq. stokes. If the image has 0 spectral channels or stokes, the corresponding length of the axis in the provided matrix should be 1.

casacore::ImageBeamSet::ImageBeamSet ( const GaussianBeam & beam )

construct an ImageBeamSet representing a single beam which is valid for all channels and stokes

casacore::ImageBeamSet::ImageBeamSet	(	uInt	nchan,
		uInt	nstokes,
		const GaussianBeam &	beam = `GaussianBeam::NULL_BEAM`
	)

Create an ImageBeamSet of the specified shape with all GaussianBeams initialized to beam.

casacore::ImageBeamSet::ImageBeamSet ( const ImageBeamSet & other )

The copy constructor (reference semantics).

casacore::ImageBeamSet::~ImageBeamSet ( )

Member Function Documentation

static void casacore::ImageBeamSet::_beamToStream	(	ostream &	os,
		const GaussianBeam &	beam,
		const Unit &	unit
	)			`[static, private]`

void casacore::ImageBeamSet::_calculateAreas ( ) [private]

static void casacore::ImageBeamSet::_chanInfoToStream	(	ostream &	os,
		const SpectralCoordinate *	spCoord,
		const uInt	chan,
		const uInt	chanWidth,
		const uInt	freqPrec,
		const uInt	velWidth,
		const uInt	velPrec
	)			`[static, private]`

static const String& casacore::ImageBeamSet::className ( ) [static]

Bool casacore::ImageBeamSet::empty ( ) const [inline]

Is the beam set empty?

Definition at line 148 of file ImageBeamSet.h.

References _beams, and casacore::ArrayBase::empty().

Referenced by casacore::ImageInfo::hasBeam().

Bool casacore::ImageBeamSet::equivalent ( const ImageBeamSet & that ) const

Beam sets are equivalent if both have no beams or if the expanded sets are equal.

Expanded means that an axis can have length 0 or 1 and is (virtually) expanded to the length of the matching axis in the other beam set.

static ImageBeamSet casacore::ImageBeamSet::fromRecord ( const Record & rec ) [static]

convert ImageBeamSet to and from record

const GaussianBeam& casacore::ImageBeamSet::getBeam	(	Int	chan,
		Int	stokes
	)			const

Get the beam at the specified location.

Note that a single channel or stokes in the beam set is valid for all channels cq. stokes.

const GaussianBeam& casacore::ImageBeamSet::getBeam ( ) const

Get the single global beam.

If there are multiple beams, an exception is thrown.

Referenced by operator()().

const Matrix<GaussianBeam>& casacore::ImageBeamSet::getBeams ( ) const [inline]

Get the beam array.

Definition at line 203 of file ImageBeamSet.h.

References _beams.

GaussianBeam casacore::ImageBeamSet::getMaxAreaBeam ( ) const [inline]

Get the beam in the set which has the largest area.

Definition at line 221 of file ImageBeamSet.h.

References _maxBeam.

const GaussianBeam& casacore::ImageBeamSet::getMaxAreaBeamForPol	(	IPosition &	pos,
		uInt	stokes
	)			const

IPosition casacore::ImageBeamSet::getMaxAreaBeamPosition ( ) const [inline]

Get the position of the beam with the maximum area.

Definition at line 232 of file ImageBeamSet.h.

References _maxBeamPos.

GaussianBeam casacore::ImageBeamSet::getMedianAreaBeam ( ) const

Get the beam in the set which has the median area.

const GaussianBeam& casacore::ImageBeamSet::getMedianAreaBeamForPol	(	IPosition &	pos,
		uInt	stokes
	)			const

GaussianBeam casacore::ImageBeamSet::getMinAreaBeam ( ) const [inline]

Get the beam in the set which has the smallest area.

Definition at line 216 of file ImageBeamSet.h.

References _minBeam.

const GaussianBeam& casacore::ImageBeamSet::getMinAreaBeamForPol	(	IPosition &	pos,
		uInt	stokes
	)			const

Get the minimal, maximal, and median area beams and positions in the beam set matrix for the given stokes.

If the stokes axis has length 1 in the beam matrix, it is valid for all stokes and no checking is done that stokes is valid; the requested beam for the entire beam set is simply returned in this case. If the number of stokes in the beam matrix is >1, checking is done that the specified value of stokes is valid and if not, an exception is thrown.

IPosition casacore::ImageBeamSet::getMinAreaBeamPosition ( ) const [inline]

Get the position of the beam with the minimum area.

Definition at line 228 of file ImageBeamSet.h.

References _minBeamPos.

const GaussianBeam casacore::ImageBeamSet::getSmallestMinorAxisBeam ( ) const

Get the beam that has the smallest minor axis.

If multiple beams have the smallest minor axis, the beam in this subset with the smallest area will be returned.

Bool casacore::ImageBeamSet::hasMultiBeam ( ) const [inline]

Does this beam set contain multiple beams?

Definition at line 143 of file ImageBeamSet.h.

References _beams, and casacore::ArrayBase::size().

Referenced by casacore::ImageInfo::hasMultipleBeams().

Bool casacore::ImageBeamSet::hasSingleBeam ( ) const [inline]

Definition at line 139 of file ImageBeamSet.h.

References _beams, and casacore::ArrayBase::size().

Referenced by casacore::ImageInfo::hasSingleBeam().

uInt casacore::ImageBeamSet::nchan ( ) const [inline]

Get the number of channels in the beam array.

NOte that this will always return a minimum of 1, even if nchan was specified as 0 on construction.

Definition at line 158 of file ImageBeamSet.h.

References _beams, and casacore::Matrix< T >::shape().

Referenced by casacore::ImageInfo::nChannels().

uInt casacore::ImageBeamSet::nelements ( ) const [inline]

Get the number of elements in the beam array.

Definition at line 133 of file ImageBeamSet.h.

References _beams, and casacore::ArrayBase::size().

uInt casacore::ImageBeamSet::nstokes ( ) const [inline]

Get the number of stokes in the beam array.

Note that this will always return a minimum of 1, even if nstokes was specified as 0 on construction.

Definition at line 163 of file ImageBeamSet.h.

References _beams, and casacore::Matrix< T >::shape().

Referenced by casacore::ImageInfo::nStokes().

Bool casacore::ImageBeamSet::operator!= ( const ImageBeamSet & other ) const

const GaussianBeam& casacore::ImageBeamSet::operator()	(	Int	chan,
		Int	stokes
	)			const `[inline]`

Definition at line 175 of file ImageBeamSet.h.

References getBeam().

ImageBeamSet& casacore::ImageBeamSet::operator= ( const ImageBeamSet & other )

Assignment can change the shape (copy semantics).

Bool casacore::ImageBeamSet::operator== ( const ImageBeamSet & other ) const

Beam sets are equal if the shapes and all corresponding beams are equal.

void casacore::ImageBeamSet::resize	(	uInt	nchan,
		uInt	nstokes
	)

Resize the beam array.

nchan=0 or nstokes=0 is silently changed to 1.

void casacore::ImageBeamSet::rotate ( const Quantity & angle )

Modify the beam set by rotating all beams counterclockwise through the specified angle.

void casacore::ImageBeamSet::set ( const GaussianBeam & beam )

Set all beams to the same value.

void casacore::ImageBeamSet::setBeam	(	Int	chan,
		Int	stokes,
		const GaussianBeam &	beam
	)

Get a beam at the given 2-dim IPosition.

It should match exactly, thus a single channel or stokes in the beam set is not valid for all. const GaussianBeam& getBeam(const IPosition& pos) const { return _beams(pos); }

Set the beam at the given location. The location must be within the beam set shape. If chan or stokes is negative, then the beam applies to all channels or stokes, respectively. If both are negative, the specified beam becomes the global beam and the beam set is resized to (1, 1).

void casacore::ImageBeamSet::setBeams ( const Matrix< GaussianBeam > & beams )

Set the beams in this beam set.

The shape of the given array must match the beam set. It also matches if an axis in array or beam set has length 1, which means that it expands to the other length.

const IPosition& casacore::ImageBeamSet::shape ( ) const [inline]

Get the shape of the beam array.

The minimum value for a component of the returned IPosition is always 1.

Definition at line 153 of file ImageBeamSet.h.

References _beams, and casacore::Matrix< T >::shape().

uInt casacore::ImageBeamSet::size ( ) const [inline]

Definition at line 135 of file ImageBeamSet.h.

References _beams, and casacore::ArrayBase::size().