An FTMachine for Gridded Fourier transforms. More...

#include <rGridFT.h>

Inheritance diagram for casa::rGridFT:

Public Member Functions
	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::String convType="SF", casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)
	Constructor: cachesize is the size of the cache in words (e.g. More...

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::String convType, casacore::MPosition mLocation, casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::String convType, casacore::MDirection mTangent, casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::String convType, casacore::MPosition mLocation, casacore::MDirection mTangent, casacore::Float passing=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (const casacore::RecordInterface &stateRec)
	Construct from a casacore::Record containing the GridFT state. More...

	rGridFT (const rGridFT &other)
	Copy constructor. More...

rGridFT &	operator= (const rGridFT &other)
	Assignment operator. More...

	~rGridFT ()

void	initializeToVis (casacore::ImageInterface< casacore::Complex > &image, const VisBuffer &vb)
	Initialize transform to Visibility plane using the image as a template. More...

void	finalizeToVis ()
	Finalize transform to Visibility plane: flushes the image cache and shows statistics if it is being used. More...

void	initializeToSky (casacore::ImageInterface< casacore::Complex > &image, casacore::Matrix< casacore::Float > &weight, const VisBuffer &vb)
	Initialize transform to Sky plane: initializes the image. More...

void	finalizeToSky ()
	Finalize transform to Sky plane: flushes the image cache and shows statistics if it is being used. More...

void	get (VisBuffer &vb, casacore::Int row=-1)
	Get actual coherence from grid by degridding. More...

void	put (const VisBuffer &vb, casacore::Int row=-1, casacore::Bool dopsf=false, FTMachine::Type type=FTMachine::OBSERVED)
	Put coherence to grid by gridding. More...

void	makeImage (FTMachine::Type type, VisSet &vs, casacore::ImageInterface< casacore::Complex > &image, casacore::Matrix< casacore::Float > &weight)
	Make the entire image. More...

casacore::ImageInterface < casacore::Complex > &	getImage (casacore::Matrix< casacore::Float > &, casacore::Bool normalize=true)
	Get the final image: do the Fourier transform and grid-correct, then optionally normalize by the summed weights. More...

virtual void	normalizeImage (casacore::Lattice< casacore::Complex > &, const casacore::Matrix< casacore::Double > &, casacore::Lattice< casacore::Float > &, casacore::Bool)

void	getWeightImage (casacore::ImageInterface< casacore::Float > &, casacore::Matrix< casacore::Float > &)
	Get the final weights image. More...

virtual casacore::Bool	toRecord (casacore::String &error, casacore::RecordInterface &outRec, casacore::Bool withImage=false, const casacore::String diskimage="")
	Save and restore the GridFT to and from a record. More...

virtual casacore::Bool	fromRecord (casacore::String &error, const casacore::RecordInterface &inRec)

virtual casacore::Bool	isFourier ()
	Can this FTMachine be represented by Fourier convolutions? More...

virtual void	setNoPadding (casacore::Bool nopad)
	To make sure no padding is used in certain gridders. More...

virtual casacore::String	name () const
	Return the name of the machine. More...

virtual void	setMiscInfo (const casacore::Int qualifier)
	set the order of the Taylor term for MFS this is to tell A-casacore::Projection to qualify the accumulated avgPB for each Taylor term in the CFCache. More...

virtual void	ComputeResiduals (VisBuffer &, casacore::Bool)
	Make the VB and VBStore interefaces for the interim re-factoring work. More...

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::CountedPtr< VisibilityResamplerBase > &visResampler, casacore::String convType="SF", casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)
	Constructor: cachesize is the size of the cache in words (e.g. More...

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::CountedPtr< VisibilityResamplerBase > &visResampler, casacore::String convType, casacore::MPosition mLocation, casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::CountedPtr< VisibilityResamplerBase > &visResampler, casacore::String convType, casacore::MDirection mTangent, casacore::Float padding=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (casacore::Long cachesize, casacore::Int tilesize, casacore::CountedPtr< VisibilityResamplerBase > &visResampler, casacore::String convType, casacore::MPosition mLocation, casacore::MDirection mTangent, casacore::Float passing=1.0, casacore::Bool usezero=true, casacore::Bool useDoublePrec=false)

	rGridFT (const casacore::RecordInterface &stateRec)
	Construct from a casacore::Record containing the rGridFT state. More...

	rGridFT (const rGridFT &other)
	Copy constructor. More...

rGridFT &	operator= (const rGridFT &other)
	Assignment operator. More...

rGridFT *	clone ()
	Clone. More...

	~rGridFT ()

void	initializeToVis (casacore::ImageInterface< casacore::Complex > &image, const VisBuffer &vb)
	Initialize transform to Visibility plane using the image as a template. More...

void	finalizeToVis ()
	Finalize transform to Visibility plane: flushes the image cache and shows statistics if it is being used. More...

void	initializeToSky (casacore::ImageInterface< casacore::Complex > &image, casacore::Matrix< casacore::Float > &weight, const VisBuffer &vb)
	Initialize transform to Sky plane: initializes the image. More...

void	finalizeToSky ()
	Finalize transform to Sky plane: flushes the image cache and shows statistics if it is being used. More...

void	get (VisBuffer &vb, casacore::Int row=-1)
	Get actual coherence from grid by degridding. More...

void	put (const VisBuffer &vb, casacore::Int row=-1, casacore::Bool dopsf=false, FTMachine::Type type=FTMachine::OBSERVED)
	Put coherence to grid by gridding. More...

void	makeImage (FTMachine::Type type, VisSet &vs, casacore::ImageInterface< casacore::Complex > &image, casacore::Matrix< casacore::Float > &weight)
	Make the entire image. More...

casacore::ImageInterface < casacore::Complex > &	getImage (casacore::Matrix< casacore::Float > &, casacore::Bool normalize=true)
	Get the final image: do the Fourier transform and grid-correct, then optionally normalize by the summed weights. More...

virtual void	normalizeImage (casacore::Lattice< casacore::Complex > &skyImage, const casacore::Matrix< casacore::Double > &sumOfWts, casacore::Lattice< casacore::Float > &sensitivityImage, casacore::Bool fftNorm)

void	getWeightImage (casacore::ImageInterface< casacore::Float > &, casacore::Matrix< casacore::Float > &)
	Get the final weights image. More...

virtual casacore::Bool	toRecord (casacore::String &error, casacore::RecordInterface &outRec, casacore::Bool withImage=false)
	Save and restore the rGridFT to and from a record. More...

virtual casacore::Bool	fromRecord (casacore::String &error, const casacore::RecordInterface &inRec)

virtual casacore::Bool	isFourier ()
	Can this FTMachine be represented by Fourier convolutions? More...

virtual void	setNoPadding (casacore::Bool nopad)
	To make sure no padding is used in certain gridders. More...

virtual casacore::String	name ()

virtual void	setMiscInfo (const casacore::Int qualifier)
	set the order of the Taylor term for MFS this is to tell A-casacore::Projection to qualify the accumulated avgPB for each Taylor term in the CFCache. More...

virtual void	ComputeResiduals (VisBuffer &vb, casacore::Bool useCorrected)
	Make the VB and VBStore interefaces for the interim re-factoring work. More...

Public Member Functions inherited from casa::FTMachine
	FTMachine ()

	FTMachine (casacore::CountedPtr< CFCache > &cfcache, casacore::CountedPtr< ConvolutionFunction > &cfctor)

	FTMachine (const FTMachine &other)

FTMachine &	operator= (const FTMachine &other)

void	setBasePrivates (const FTMachine &other)

virtual	~FTMachine ()

virtual FTMachine *	cloneFTM ()
	clone copy the default cloner clones via a Record copy More...

virtual void	initializeToVis (casacore::Block< casacore::CountedPtr< casacore::ImageInterface< casacore::Complex > > > &compImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &modelImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &weightImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &fluxScaleVec, casacore::Block< casacore::Matrix< casacore::Float > > &weightsVec, const VisBuffer &vb)
	Vectorized InitializeToVis. More...

virtual void	initializeToVisNew (const VisBuffer &vb, casacore::CountedPtr< SIImageStore > imstore)

virtual void	initializeToSky (casacore::Block< casacore::CountedPtr< casacore::ImageInterface< casacore::Complex > > > &compImageVec, casacore::Block< casacore::Matrix< casacore::Float > > &weightsVec, const VisBuffer &vb, const casacore::Bool dopsf=false)
	Vectorized InitializeToSky. More...

virtual void	initializeToSkyNew (const casacore::Bool dopsf, const VisBuffer &vb, casacore::CountedPtr< SIImageStore > imstore)

virtual void	finalizeToSky (casacore::ImageInterface< casacore::Complex > &iimage)

virtual void	finalizeToSky (casacore::Block< casacore::CountedPtr< casacore::ImageInterface< casacore::Complex > > > &compImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &resImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &weightImageVec, casacore::PtrBlock< casacore::SubImage< casacore::Float > * > &fluxScaleVec, casacore::Bool dopsf, casacore::Block< casacore::Matrix< casacore::Float > > &weightsVec, const VisBuffer &vb)
	Vectorized finalizeToSky. More...

virtual void	finalizeToSkyNew (casacore::Bool dopsf, const VisBuffer &vb, casacore::CountedPtr< SIImageStore > imstore)

virtual void	put (VisBuffer &vb, casacore::Int row=-1, casacore::Bool dopsf=false, FTMachine::Type type=FTMachine::OBSERVED)
	Non const vb version - so that weights can be modified in-place Currently, used only by MultiTermFT. More...

virtual void	correlationToStokes (casacore::ImageInterface< casacore::Complex > &compImage, casacore::ImageInterface< casacore::Float > &resImage, const casacore::Bool dopsf)
	More...

virtual void	stokesToCorrelation (casacore::ImageInterface< casacore::Float > &modelImage, casacore::ImageInterface< casacore::Complex > &compImage)

virtual void	normalizeImage (casacore::ImageInterface< casacore::Float > &skyImage, casacore::Matrix< casacore::Float > &sumOfWts, casacore::ImageInterface< casacore::Float > &sensitivityImage, casacore::Bool dopsf, casacore::Float pblimit, casacore::Int normtype)

virtual casacore::Bool	useWeightImage ()
	All FTMachines that fill weightimage, need to set this. More...

virtual casacore::Bool	isSkyJonesSet ()

virtual casacore::Bool	isSkyJonesChanged (VisBuffer &vb, casacore::Int row)

virtual void	setSkyJones (casacore::Vector< casacore::CountedPtr< SkyJones > > &sj)
	Set SkyJones if image domain corrections /applycation are needed To reset the the FTMachine for stopping image based correction/applycation set in a casacore::Vector of size 0. More...

casacore::Bool	changedSkyJonesLogic (const VisBuffer &vb, casacore::Bool &firstRow, casacore::Bool &internalRow)

template<typename T >
void	getGrid (casacore::Array< T > &thegrid)
	More...

virtual const casacore::CountedPtr < ConvolutionFunction > &	getAWConvFunc ()

virtual void	findConvFunction (const casacore::ImageInterface< casacore::Complex > &, const VisBuffer &)

virtual void	getFluxImage (casacore::ImageInterface< casacore::Float > &image)
	Get a flux (divide by this to get a flux density correct image) image if there is one. More...

virtual void	makeImage (FTMachine::Type type, ROVisibilityIterator &vi, casacore::ImageInterface< casacore::Complex > &image, casacore::Matrix< casacore::Float > &weight)
	Make the entire image using a ROVisIter. More...

void	girarUVW (casacore::Matrix< casacore::Double > &uvw, casacore::Vector< casacore::Double > &dphase, const VisBuffer &vb)
	More...

void	rotateUVW (casacore::Matrix< casacore::Double > &uvw, casacore::Vector< casacore::Double > &dphase, const VisBuffer &vb)

void	refocus (casacore::Matrix< casacore::Double > &uvw, const casacore::Vector< casacore::Int > &ant1, const casacore::Vector< casacore::Int > &ant2, casacore::Vector< casacore::Double > &dphase, const VisBuffer &vb)
	Refocus on a finite distance. More...

virtual casacore::Bool	changed (const VisBuffer &vb)
	Has this operator changed since the last application? More...

casacore::Bool	setSpw (casacore::Vector< casacore::Int > &spw, casacore::Bool validFrame)
	set spw for cube that will be used; More...

virtual casacore::Bool	doublePrecGrid ()
	return whether the ftmachine is using a double precision grid More...

void	setLocation (const casacore::MPosition &loc)
	set and get the location used for frame More...

casacore::MPosition &	getLocation ()

virtual void	setMovingSource (const casacore::String &sourcename)
	set a moving source aka planets or comets => adjust phase center on the fly for gridding More...

virtual void	setMovingSource (const casacore::MDirection &mdir)

void	setPhaseCenterTime (const casacore::Double time)
	set and get Time to calculate phasecenter -1.0 means using the time available at each iteration..this is used when the phasecenter in the field table is either a polynomial or has a ephemerides tables associated with it Using double in the units and epoch-frame of the ms(s)..caller is responsible for conversion More...

casacore::Double	getPhaseCenterTime ()

virtual void	reset ()
	reset stuff in an FTMachine More...

virtual void	setFreqInterpolation (const casacore::String &method)
	set frequency interpolation type More...

virtual void	setPointingDirColumn (const casacore::String &column="DIRECTION")
	tell ftmachine which Pointing table column to use for Direction Mosaic or Single dish ft use this for example More...

virtual casacore::String	getPointingDirColumnInUse ()

virtual void	setSpwChanSelection (const casacore::Cube< casacore::Int > &spwchansels)

virtual casacore::Cube < casacore::Int >	getSpwChanSelection ()

virtual void	setSpwFreqSelection (const casacore::Matrix< casacore::Double > &spwfreqs)

virtual casacore::Matrix < casacore::Double >	getSpwFreqSelection ()

virtual void	setCanComputeResiduals (casacore::Bool &b)

virtual casacore::Bool	canComputeResiduals ()

virtual casacore::Float	getPBLimit ()

void	setnumthreads (casacore::Int n)
	virtual void ComputeResiduals(VBStore& vb)=0; get and set numthreads More...

casacore::Int	getnumthreads ()

virtual void	setCFCache (casacore::CountedPtr< CFCache > &cfc, const casacore::Bool resetCFC=true)

casacore::CountedPtr< CFCache >	getCFCache ()

casacore::String	getCacheDir ()

virtual void	setDryRun (casacore::Bool val)

virtual casacore::Bool	dryRun ()

virtual casacore::Bool	isUsingCFCache ()

Protected Member Functions
casacore::Array < casacore::Complex > *	getDataPointer (const casacore::IPosition &, casacore::Bool)
	Get the appropriate data pointer. More...

void	ok ()

void	init ()

void	prepGridForDegrid ()
	Prepare the grid for degridding. More...

casacore::Bool	recordOnGrid (const VisBuffer &vb, casacore::Int rownr) const
	Is this record on Grid? check both ends. More...

casacore::Array < casacore::Complex > *	getDataPointer (const casacore::IPosition &, casacore::Bool)
	Get the appropriate data pointer. More...

void	ok ()

void	init ()

casacore::Bool	recordOnGrid (const VisBuffer &vb, casacore::Int rownr) const
	Is this record on Grid? check both ends. More...

Protected Member Functions inherited from casa::FTMachine
casacore::LogIO &	logIO ()

virtual void	initMaps (const VisBuffer &vb)

virtual void	initPolInfo (const VisBuffer &vb)

virtual void	gridOk (casacore::Int gridsupport)
	check if image is big enough for gridding More...

casacore::Bool	matchChannel (const casacore::Int &spw, const VisBuffer &vb)

casacore::Bool	matchAllSpwChans (const VisBuffer &vb)
	redo all spw chan match especially if ms has changed underneath More...

virtual casacore::Bool	interpolateFrequencyTogrid (const VisBuffer &vb, const casacore::Matrix< casacore::Float > &wt, casacore::Cube< casacore::Complex > &data, casacore::Cube< casacore::Int > &flag, casacore::Matrix< casacore::Float > &weight, FTMachine::Type type=FTMachine::OBSERVED)
	interpolate visibility data of vb to grid frequency definition flag will be set the one as described in interpolateArray1D return false if no interpolation is done...for e.g for nearest case More...

virtual casacore::Bool	interpolateFrequencyFromgrid (VisBuffer &vb, casacore::Cube< casacore::Complex > &data, FTMachine::Type type=FTMachine::MODEL)
	degridded data interpolated back onto visibilities More...

virtual void	getInterpolateArrays (const VisBuffer &vb, casacore::Cube< casacore::Complex > &data, casacore::Cube< casacore::Int > &flag)
	Interpolate visibilities to be degridded upon. More...

void	setSpectralFlag (const VisBuffer &vb, casacore::Cube< casacore::Bool > &modflagcube)

casacore::Bool	saveMeasure (casacore::RecordInterface &rec, const casacore::String &name, casacore::String &error, const casacore::Measure &ms)
	helper to save Measures in a record More...

Protected Attributes
casacore::Float	padding_p
	Padding in FFT. More...

casacore::LatticeCache < casacore::Complex > *	imageCache
	Image cache. More...

casacore::Long	cachesize
	Sizes. More...

casacore::Int	tilesize

casacore::ConvolveGridder < casacore::Double, casacore::Complex > *	gridder
	Gridder. More...

casacore::Bool	isTiled
	Is this tiled? More...

casacore::CountedPtr < casacore::Lattice < casacore::Complex > >	arrayLattice
	casacore::Array lattice More...

casacore::CountedPtr < casacore::Lattice < casacore::Complex > >	lattice
	Lattice. More...

casacore::String	convType

casacore::Float	maxAbsData

casacore::IPosition	centerLoc
	Useful IPositions. More...

casacore::IPosition	offsetLoc

casacore::Vector < casacore::Double >	uvScale
	Image Scaling and offset. More...

casacore::Vector < casacore::Double >	uvOffset

casacore::Int	priorCacheSize

casacore::Bool	usezero_p
	Grid/degrid zero spacing points? More...

casacore::Bool	noPadding_p
	force no padding More...

casacore::Bool	usePut2_p
	Check if using put that avoids non-necessary reads. More...

casacore::String	machineName_p
	machine name More...

casacore::Double	timemass_p

casacore::Double	timegrid_p

casacore::Array < casacore::Complex >	griddedData
	casacore::Array for non-tiled gridding More...

casacore::Array < casacore::DComplex >	griddedData2

casacore::CountedPtr < VisibilityResamplerBase >	visResampler_p
	VisibilityResampler - a.k.a the "gridder" object VisibilityResampler visResampler_p; casacore::CountedPtr<MultiThreadedVisibilityResampler> visResampler_p;. More...

Protected Attributes inherited from casa::FTMachine
casacore::LogIO	logIO_p

casacore::ImageInterface < casacore::Complex > *	image

casacore::UVWMachine *	uvwMachine_p

casacore::CountedPtr < casacore::UVWMachine >	phaseShifter_p

casacore::MeasFrame	mFrame_p

casacore::Bool	tangentSpecified_p
	Direction of desired tangent plane. More...

casacore::MDirection	mTangent_p

casacore::MDirection	mImage_p

casacore::MDirection	movingDir_p
	moving source stuff More...

casacore::Bool	fixMovingSource_p

casacore::MDirection	firstMovingDir_p

casacore::Double	distance_p

casacore::uInt	nAntenna_p

casacore::Int	lastFieldId_p

casacore::Int	lastMSId_p

casacore::Bool	useDoubleGrid_p
	Use douple precision grid in gridding process. More...

casacore::Matrix < casacore::Double >	sumWeight
	Sum of weights per polarization and per chan. More...

casacore::Matrix < casacore::Double >	sumCFWeight

casacore::Int	nx
	Sizes. More...

casacore::Int	ny

casacore::Int	npol

casacore::Int	nchan

casacore::Int	nvischan

casacore::Int	nvispol

casacore::Vector< casacore::Int >	chanMap
	Maps of channels and polarization. More...

casacore::Vector< casacore::Int >	polMap

casacore::Bool	isIOnly
	Is casacore::Stokes I only? iso XX,XY,YX,YY or LL,LR,RL,RR. More...

casacore::MPosition	mLocation_p
	Default Position used for phase rotations. More...

casacore::Bool	doUVWRotation_p
	Set if uvwrotation is necessary. More...

casacore::Block < casacore::Vector < casacore::Int > >	multiChanMap_p
	setup multiple spectral window for cubes More...

casacore::Vector< casacore::Int >	selectedSpw_p

casacore::Vector< casacore::Int >	nVisChan_p

casacore::SpectralCoordinate	spectralCoord_p
	Private variables needed for spectral frame conversion. More...

casacore::Vector< casacore::Bool >	doConversion_p

casacore::Bool	freqFrameValid_p

casacore::Vector < casacore::Double >	imageFreq_p

casacore::Vector < casacore::Double >	lsrFreq_p
	casacore::Vector of float lsrfreq needed for regridding More...

casacore::Vector < casacore::Double >	interpVisFreq_p

casacore::InterpolateArray1D < casacore::Double, casacore::Complex > ::InterpolationMethod	freqInterpMethod_p

casacore::String	pointingDirCol_p

casacore::Cube< casacore::Int >	spwChanSelFlag_p

casacore::Matrix < casacore::Double >	spwFreqSel_p

casacore::Matrix < casacore::Double >	expandedSpwFreqSel_p

casacore::Matrix < casacore::Double >	expandedSpwConjFreqSel_p

casacore::Vector< casacore::Int >	cfStokes_p

casacore::Int	polInUse_p

casacore::CountedPtr< CFCache >	cfCache_p

CFStore	cfs_p

CFStore	cfwts_p

casacore::CountedPtr< CFStore2 >	cfs2_p

casacore::CountedPtr< CFStore2 >	cfwts2_p

casacore::CountedPtr < ConvolutionFunction >	convFuncCtor_p

casacore::CountedPtr < PolOuterProduct >	pop_p

casacore::Bool	canComputeResiduals_p

casacore::Bool	toVis_p

casacore::Int	numthreads_p

casacore::Array < casacore::Complex >	griddedData
	casacore::Array for non-tiled gridding These are common to most FTmachines More...

casacore::Array < casacore::DComplex >	griddedData2

casacore::Float	pbLimit_p

casacore::Vector < casacore::CountedPtr < SkyJones > >	sj_p
	casacore::Vector<SkyJones *> sj_p; More...

casacore::CountedPtr < casacore::ImageInterface < casacore::Complex > >	cmplxImage_p
	A holder for the complex image if nobody else is keeping it. More...

FFT2D	ft_p

casacore::Double	phaseCenterTime_p

Additional Inherited Members
Public Types inherited from casa::FTMachine
enum	Type { OBSERVED, MODEL, CORRECTED, RESIDUAL, PSF, COVERAGE, N_types, DEFAULT }
	Types of known Images that may be made using the makeImage method. More...

Static Public Member Functions inherited from casa::FTMachine
static void	locateuvw (const casacore::Double &uvw, const casacore::Double &dphase, const casacore::Double &freq, const casacore::Int &nchan, const casacore::Double &scale, const casacore::Double &offset, const casacore::Int &sampling, casacore::Int &loc, casacore::Int &off, casacore::Complex &phasor, const casacore::Int &row, const casacore::Bool &doW=false)
	helper function for openmp to call...no private dependency More...

Public Attributes inherited from casa::FTMachine
casacore::Bool	isDryRun

Detailed Description

An FTMachine for Gridded Fourier transforms.

Intended use:

Public interface

Prerequisite

FTMachine module
SkyEquation module
VisBuffer module

Etymology

FTMachine is a Machine for Fourier Transforms. GridFT does Grid-based Fourier transforms.

Synopsis

The SkyEquation needs to be able to perform Fourier transforms on visibility data. GridFT allows efficient Fourier Transform processing using a VisBuffer which encapsulates a chunk of visibility (typically all baselines for one time) together with all the information needed for processing (e.g. UVW coordinates).

Gridding and degridding in GridFT are performed using a novel sort-less algorithm. In this approach, the gridded plane is divided into small patches, a cache of which is maintained in memory using a general-purpose LatticeCache class. As the (time-sorted) visibility data move around slowly in the Fourier plane, patches are swapped in and out as necessary. Thus, optimally, one would keep at least one patch per baseline.

A grid cache is defined on construction. If the gridded uv plane is smaller than this, it is kept entirely in memory and all gridding and degridding is done entirely in memory. Otherwise a cache of tiles is kept an paged in and out as necessary. Optimally the cache should be big enough to hold all polarizations and frequencies for all baselines. The paging rate will then be small. As the cache size is reduced below this critical value, paging increases. The algorithm will work for only one patch but it will be very slow!

This scheme works well for arrays having a moderate number of antennas since the saving in space goes as the ratio of baselines to image size. For the ATCA, VLBA and WSRT, this ratio is quite favorable. For the VLA, one requires images of greater than about 200 pixels on a side to make it worthwhile.

The FFT step is done plane by plane for images having less than 1024 * 1024 pixels on each plane, and line by line otherwise.

The gridding and degridding steps are implemented in Fortran for speed. In gridding, the visibilities are added onto the grid points in the neighborhood using a weighting function. In degridding, the value is derived by a weight summ of the same points, using the same weighting function.

Example

See the example for SkyModel.

Motivation

Define an interface to allow efficient processing of chunks of visibility data

Intended use:

Public interface

Prerequisite

FTMachine module
SkyEquation module
VisBuffer module

Etymology

FTMachine is a Machine for Fourier Transforms. rGridFT does Grid-based Fourier transforms.

Synopsis

The SkyEquation needs to be able to perform Fourier transforms on visibility data. rGridFT allows efficient Fourier Transform processing using a VisBuffer which encapsulates a chunk of visibility (typically all baselines for one time) together with all the information needed for processing (e.g. UVW coordinates).

Gridding and degridding in rGridFT are performed using a novel sort-less algorithm. In this approach, the gridded plane is divided into small patches, a cache of which is maintained in memory using a general-purpose LatticeCache class. As the (time-sorted) visibility data move around slowly in the Fourier plane, patches are swapped in and out as necessary. Thus, optimally, one would keep at least one patch per baseline.

A grid cache is defined on construction. If the gridded uv plane is smaller than this, it is kept entirely in memory and all gridding and degridding is done entirely in memory. Otherwise a cache of tiles is kept an paged in and out as necessary. Optimally the cache should be big enough to hold all polarizations and frequencies for all baselines. The paging rate will then be small. As the cache size is reduced below this critical value, paging increases. The algorithm will work for only one patch but it will be very slow!

This scheme works well for arrays having a moderate number of antennas since the saving in space goes as the ratio of baselines to image size. For the ATCA, VLBA and WSRT, this ratio is quite favorable. For the VLA, one requires images of greater than about 200 pixels on a side to make it worthwhile.

The FFT step is done plane by plane for images having less than 1024 * 1024 pixels on each plane, and line by line otherwise.

The gridding and degridding steps are implemented in Fortran for speed. In gridding, the visibilities are added onto the grid points in the neighborhood using a weighting function. In degridding, the value is derived by a weight summ of the same points, using the same weighting function.

Example

See the example for SkyModel.

Motivation

Define an interface to allow efficient processing of chunks of visibility data

Definition at line 127 of file rGridFT.h.

Constructor & Destructor Documentation

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::String	convType = `"SF"`,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

Constructor: cachesize is the size of the cache in words (e.g.

a few million is a good number), tilesize is the size of the tile used in gridding (cannot be less than 12, 16 works in most cases), and convType is the type of gridding used (SF is prolate spheriodal wavefunction, and BOX is plain box-car summation). mLocation is the position to be used in some phase rotations. If mTangent is specified then the uvw rotation is done for that location iso the image center.

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::String	convType,
		casacore::MPosition	mLocation,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::String	convType,
		casacore::MDirection	mTangent,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::String	convType,
		casacore::MPosition	mLocation,
		casacore::MDirection	mTangent,
		casacore::Float	passing = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT ( const casacore::RecordInterface & stateRec )

Construct from a casacore::Record containing the GridFT state.

casa::rGridFT::rGridFT ( const rGridFT & other )

Copy constructor.

casa::rGridFT::~rGridFT ( )

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::CountedPtr< VisibilityResamplerBase > &	visResampler,
		casacore::String	convType = `"SF"`,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

Constructor: cachesize is the size of the cache in words (e.g.

a few million is a good number), tilesize is the size of the tile used in gridding (cannot be less than 12, 16 works in most cases), and convType is the type of gridding used (SF is prolate spheriodal wavefunction, and BOX is plain box-car summation). mLocation is the position to be used in some phase rotations. If mTangent is specified then the uvw rotation is done for that location iso the image center.

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::CountedPtr< VisibilityResamplerBase > &	visResampler,
		casacore::String	convType,
		casacore::MPosition	mLocation,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::CountedPtr< VisibilityResamplerBase > &	visResampler,
		casacore::String	convType,
		casacore::MDirection	mTangent,
		casacore::Float	padding = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT	(	casacore::Long	cachesize,
		casacore::Int	tilesize,
		casacore::CountedPtr< VisibilityResamplerBase > &	visResampler,
		casacore::String	convType,
		casacore::MPosition	mLocation,
		casacore::MDirection	mTangent,
		casacore::Float	passing = `1.0`,
		casacore::Bool	usezero = `true`,
		casacore::Bool	useDoublePrec = `false`
	)

casa::rGridFT::rGridFT ( const casacore::RecordInterface & stateRec )

Construct from a casacore::Record containing the rGridFT state.

casa::rGridFT::rGridFT ( const rGridFT & other )

Copy constructor.

casa::rGridFT::~rGridFT ( )

Member Function Documentation

rGridFT* casa::rGridFT::clone ( )

Clone.

virtual void casa::rGridFT::ComputeResiduals	(	VisBuffer &	vb,
		casacore::Bool	useCorrected
	)

inlinevirtual

Make the VB and VBStore interefaces for the interim re-factoring work.

Finally removed the VB interface.

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Intended use:

Prerequisite

Etymology

Synopsis

Example

Motivation

Intended use:

Prerequisite

Etymology

Synopsis

Example

Motivation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation