Fits and optionally subtracts the continuum in visibility spectra. More...

#include <VBContinuumSubtractor.h>

Public Member Functions
	VBContinuumSubtractor ()

	VBContinuumSubtractor (const casacore::Double lofreq, const casacore::Double hifreq)
	Construct it with the low and high frequencies used for scaling the frequencies in the polynomial. More...

	~VBContinuumSubtractor ()

void	init (const casacore::IPosition &shp, const casacore::uInt maxAnt, const casacore::uInt totnumchan, const casacore::Double lof, const casacore::Double hif)
	Set the # of correlations and fitorder from shp, the total number of input channels to look at (including masked ones!), and the low and high scaling frequencies. More...

casacore::Bool	initFromVBGA (VisBuffGroupAcc &vbga)
	Set the low and high frequencies, and #s of correlations, antennas, and channels from vbga. More...

void	fit (VisBuffGroupAcc &vbga, const casacore::Int fitorder, casacore::MS::PredefinedColumns whichcol, casacore::Cube< casacore::Complex > &coeffs, casacore::Cube< casacore::Bool > &coeffsOK, const casacore::Bool doInit=false, const casacore::Bool doResize=false, const casacore::Bool squawk=true)
	Makes the continuum estimate by fitting a frequency polynomial of order fitorder to the data in vbga. More...

casacore::Bool	apply (VisBuffer &vb, const casacore::MS::PredefinedColumns whichcol, const casacore::Cube< casacore::Complex > &coeffs, const casacore::Cube< casacore::Bool > &coeffsOK, const casacore::Bool doSubtraction=true, const casacore::Bool squawk=true)
	Apply the continuum estimate in coeffs (from fit) to vb. More...

casacore::Bool	areFreqsInBounds (VisBuffer &vb, const casacore::Bool squawk) const
	Returns whether or not vb's frequencies are within the bounds used for the continuum fit. More...

casacore::Bool	areFreqsInBounds (vi::VisBuffer2 &vb, const casacore::Bool squawk) const

casacore::Int	getOrder () const
	These are provided for the calibration framework so that a VBContinuumSubtractor can be c'ted from a VisBuffGroupAcc, make a continuum fit, write its results to a caltable, destroyed, and then later another one can be c'ted from the caltable and apply the fit to a VisBuffer. More...

casacore::Double	getLowFreq () const

casacore::Double	getHighFreq () const

casacore::Int	getMaxAntNum () const
	the casacore::MS def'n v.2. More...

casacore::uInt	getTotNumChan () const
	The total number of input channels that will be looked at (including masked ones!) More...

void	setScalingFreqs (casacore::Double lof, casacore::Double hif)
	Low (lof) and high (hif) frequencies, in Hz, used for renormalizing frequencies in the polynomials. More...

void	setNAnt (const casacore::uInt nAnt)
	Set the maximum number of antennas (actually, 1 + the maximum antenna number). More...

void	setTotNumChan (const casacore::uInt tnc)
	Set the total number of input channels that will be looked at (including masked ones!) More...

void	resize (casacore::Cube< casacore::Complex > &coeffs, casacore::Cube< casacore::Bool > &coeffsOK) const
	A convenience function for prepping coeffs and coeffsOK to hold the polynomial coefficients and their validities. More...

casacore::Bool	checkSize (casacore::Cube< casacore::Complex > &coeffs, casacore::Cube< casacore::Bool > &coeffsOK) const

casacore::Double	calcFreqScale () const

void	setTVIDebug (bool debug)

casacore::Bool	apply2 (vi::VisBuffer2 &vb, casacore::Cube< casacore::Complex > &Vout, const casacore::Cube< casacore::Complex > &coeffs, const casacore::Cube< casacore::Bool > &coeffsOK, const casacore::Bool doSubtraction=true, const casacore::Bool squawk=true)

Static Public Member Functions
static void	getMinMaxFreq (VisBuffer &vb, casacore::Double &minfreq, casacore::Double &maxfreq, const casacore::Bool initialize=true)
	Fills minfreq and maxfreq with the minimum and maximum frequencies (in Hz, acc. More...

static void	getMinMaxFreq (vi::VisBuffer2 &vb, casacore::Double &minfreq, casacore::Double &maxfreq, const casacore::Bool initialize=true)

Private Member Functions
VBContinuumSubtractor &	operator= (VBContinuumSubtractor &other)
	Disable default copying, and assignment. More...

casacore::Bool	doShapesMatch (VisBuffer &vb, casacore::LogIO &os, const casacore::Bool squawk=true) const
	Can the fit be applied to vb? If not and squawk is true, send a severe message to os. More...

casacore::Bool	doShapesMatch (vi::VisBuffer2 &vb, casacore::LogIO &os, const casacore::Bool squawk=true) const

casacore::uInt	hashFunction (const casacore::Int ant1, const casacore::Int ant2)
	Compute baseline (row) index in coeffs_p for (ant1, ant2). More...

Private Attributes
casacore::Int	fitorder_p
	VisBuffGroupAcc& vbga_p; // Holds the VisBuffers. More...

casacore::Double	lofreq_p

casacore::Double	hifreq_p

casacore::Double	midfreq_p

casacore::Double	freqscale_p

casacore::Int	maxAnt_p

casacore::uInt	nHashes_p
	used with the fits. More...

casacore::uInt	ncorr_p

casacore::uInt	totnumchan_p

casacore::PtrBlock < casacore::Vector < casacore::Bool > * >	chanmask_p

bool	tvi_debug

Detailed Description

Fits and optionally subtracts the continuum in visibility spectra.

Intended use:

Public interface

Review Status

Date Reviewed:: yyyy/mm/dd

Prerequisite

MeasurementSet

Etymology

This class's main aim is to subtract the continuum from VisBuffers.

Synopsis

Spectral line observations often contain continuum emission which is present in all channels (often with a small slope and curvature across the band). This class fits a polynomial to this continuum, and can return the continuum and/or line (continuum-subtracted) estimates as VisBuffers.

Example

const casacore::Int fitorder = 4;                 // Careful!  High orders might
// absorb power from the lines.
casacore::MS inMS(fileName);
casacore::Block<casacore::Int> sortcolumns;
ROVisIter vi(inMS, sortcolumns, 0.0);
VisBuffer cvb(vi);                         // Continuum estimate
VisBuffer lvb(vi);                         // Line estimate
VisBuffer vb(vi);
for(vi.originChunks(); vi.moreChunks(); vi.nextChunk()){
for(vi.origin(); vi.more(); ++vi){
VBContinuumSubtractor contestor(vb, fitorder); // Continuum Estimator
contestor.cont_est(cvb);             // Put continuum estimate into cvb.
contestor.cont_subtracted(lvb);      // Put line estimate into lvb.
// Do something with cvb and lvb..\.
}
}

Motivation

This class provides continuum fitting by polynomials with order >= 0, with a convenient interface for use by other classes in synthesis and msvis (i.e. calibration, imaging, and split).

Definition at line 101 of file VBContinuumSubtractor.h.

Constructor & Destructor Documentation

casa::VBContinuumSubtractor::VBContinuumSubtractor ( )

casa::VBContinuumSubtractor::VBContinuumSubtractor	(	const casacore::Double	lofreq,
		const casacore::Double	hifreq
	)

Construct it with the low and high frequencies used for scaling the frequencies in the polynomial.

casa::VBContinuumSubtractor::~VBContinuumSubtractor ( )

Member Function Documentation

casacore::Bool casa::VBContinuumSubtractor::apply	(	VisBuffer &	vb,
		const casacore::MS::PredefinedColumns	whichcol,
		const casacore::Cube< casacore::Complex > &	coeffs,
		const casacore::Cube< casacore::Bool > &	coeffsOK,
		const casacore::Bool	doSubtraction = `true`,
		const casacore::Bool	squawk = `true`
	)

Apply the continuum estimate in coeffs (from fit) to vb.

The affected column of vb is chosen by whichcol, which must be exactly one of casacore::MS::DATA, casacore::MS::MODEL_DATA, or casacore::MS::CORRECTED_DATA lest an exception will be thrown. If doSubtraction is true, vb becomes the line estimate. Otherwise it is replaced with the continuum estimate. Returns false if it detects an error, true otherwise. squawk=true increases the potential number of warnings sent to the logger.

casacore::Bool casa::VBContinuumSubtractor::apply2	(	vi::VisBuffer2 &	vb,
		casacore::Cube< casacore::Complex > &	Vout,
		const casacore::Cube< casacore::Complex > &	coeffs,
		const casacore::Cube< casacore::Bool > &	coeffsOK,
		const casacore::Bool	doSubtraction = `true`,
		const casacore::Bool	squawk = `true`
	)

Parameters

coeffs const casacore::MS::PredefinedColumns whichcol,

casacore::Bool casa::VBContinuumSubtractor::areFreqsInBounds	(	VisBuffer &	vb,
		const casacore::Bool	squawk
	)		const

Returns whether or not vb's frequencies are within the bounds used for the continuum fit.

If not, and squawk is true, a warning will be sent to the logger. (Extrapolation is allowed, just not recommended.)

casacore::Bool casa::VBContinuumSubtractor::areFreqsInBounds	(	vi::VisBuffer2 &	vb,
		const casacore::Bool	squawk
	)		const

casacore::Double casa::VBContinuumSubtractor::calcFreqScale ( ) const

inline

Definition at line 221 of file VBContinuumSubtractor.h.

References hifreq_p, and midfreq_p.

Referenced by setScalingFreqs().

casacore::Bool casa::VBContinuumSubtractor::checkSize	(	casacore::Cube< casacore::Complex > &	coeffs,
		casacore::Cube< casacore::Bool > &	coeffsOK
	)		const

inline

Definition at line 211 of file VBContinuumSubtractor.h.

References fitorder_p, ncorr_p, nHashes_p, and casacore::Cube< T >::shape().

casacore::Bool casa::VBContinuumSubtractor::doShapesMatch	(	VisBuffer &	vb,
		casacore::LogIO &	os,
		const casacore::Bool	squawk = `true`
	)		const

private

Can the fit be applied to vb? If not and squawk is true, send a severe message to os.

casacore::Bool casa::VBContinuumSubtractor::doShapesMatch	(	vi::VisBuffer2 &	vb,
		casacore::LogIO &	os,
		const casacore::Bool	squawk = `true`
	)		const

private

void casa::VBContinuumSubtractor::fit	(	VisBuffGroupAcc &	vbga,
		const casacore::Int	fitorder,
		casacore::MS::PredefinedColumns	whichcol,
		casacore::Cube< casacore::Complex > &	coeffs,
		casacore::Cube< casacore::Bool > &	coeffsOK,
		const casacore::Bool	doInit = `false`,
		const casacore::Bool	doResize = `false`,
		const casacore::Bool	squawk = `true`
	)

Makes the continuum estimate by fitting a frequency polynomial of order fitorder to the data in vbga.

It sets the low and high frequencies used for scaling the frequencies in the polynomial to the min and max frequencies in vbga. casacore::Input: vbga, The data fitorder, e.g. 2 for a + bf + cf**2 doInit, if true call initFromVBGA(vbga) doResize if true set coeffs and coeffsOK to the right shape. Output (these will be resized): coeffs: casacore::Polynomial coefficients for the continuum, indexed by (corr, order, hash(ant1, ant2). coeffsOK: and whether or not they're usable.

casacore::Double casa::VBContinuumSubtractor::getHighFreq ( ) const

inline

Definition at line 179 of file VBContinuumSubtractor.h.

References hifreq_p.

casacore::Double casa::VBContinuumSubtractor::getLowFreq ( ) const

inline

Definition at line 178 of file VBContinuumSubtractor.h.

References lofreq_p.

casacore::Int casa::VBContinuumSubtractor::getMaxAntNum ( ) const

inline

the casacore::MS def'n v.2.

Definition at line 181 of file VBContinuumSubtractor.h.

References maxAnt_p.

static void casa::VBContinuumSubtractor::getMinMaxFreq	(	VisBuffer &	vb,
		casacore::Double &	minfreq,
		casacore::Double &	maxfreq,
		const casacore::Bool	initialize = `true`
	)

static

Fills minfreq and maxfreq with the minimum and maximum frequencies (in Hz, acc.

to the casacore::MS def'n v.2) of vb (not the continuum fit!). If you want to get the extreme frequencies over a set of VisBuffers, set initialize to false and initialize minfreq and maxfreq yourself to DBL_MAX and -1.0, respectively.

static void casa::VBContinuumSubtractor::getMinMaxFreq	(	vi::VisBuffer2 &	vb,
		casacore::Double &	minfreq,
		casacore::Double &	maxfreq,
		const casacore::Bool	initialize = `true`
	)

static

casacore::Int casa::VBContinuumSubtractor::getOrder ( ) const

inline

These are provided for the calibration framework so that a VBContinuumSubtractor can be c'ted from a VisBuffGroupAcc, make a continuum fit, write its results to a caltable, destroyed, and then later another one can be c'ted from the caltable and apply the fit to a VisBuffer.

Obviously it'd be safer and faster to use the same VBContinuumSubtractor for fitting and application, but the rest of CASA isn't ready for that yet (3/7/2011).

Definition at line 176 of file VBContinuumSubtractor.h.

References fitorder_p.

casacore::uInt casa::VBContinuumSubtractor::getTotNumChan ( ) const

inline

The total number of input channels that will be looked at (including masked ones!)

Definition at line 185 of file VBContinuumSubtractor.h.

References totnumchan_p.

casacore::uInt casa::VBContinuumSubtractor::hashFunction	(	const casacore::Int	ant1,
		const casacore::Int	ant2
	)

inlineprivate

Compute baseline (row) index in coeffs_p for (ant1, ant2).

It ASSUMES that ant1 and ant2 are both <= maxAnt_p.

Definition at line 248 of file VBContinuumSubtractor.h.

References maxAnt_p.

void casa::VBContinuumSubtractor::init	(	const casacore::IPosition &	shp,
		const casacore::uInt	maxAnt,
		const casacore::uInt	totnumchan,
		const casacore::Double	lof,
		const casacore::Double	hif
	)

Set the # of correlations and fitorder from shp, the total number of input channels to look at (including masked ones!), and the low and high scaling frequencies.

casacore::Bool casa::VBContinuumSubtractor::initFromVBGA ( VisBuffGroupAcc & vbga )

Set the low and high frequencies, and #s of correlations, antennas, and channels from vbga.

Returns false if vbga is empty.

VBContinuumSubtractor& casa::VBContinuumSubtractor::operator= ( VBContinuumSubtractor & other )

private

Disable default copying, and assignment.

void casa::VBContinuumSubtractor::resize	(	casacore::Cube< casacore::Complex > &	coeffs,
		casacore::Cube< casacore::Bool > &	coeffsOK
	)		const

A convenience function for prepping coeffs and coeffsOK to hold the polynomial coefficients and their validities.

void casa::VBContinuumSubtractor::setNAnt ( const casacore::uInt nAnt )

inline

Set the maximum number of antennas (actually, 1 + the maximum antenna number).

Definition at line 198 of file VBContinuumSubtractor.h.

References maxAnt_p, and nHashes_p.

void casa::VBContinuumSubtractor::setScalingFreqs	(	casacore::Double	lof,
		casacore::Double	hif
	)

inline

Low (lof) and high (hif) frequencies, in Hz, used for renormalizing frequencies in the polynomials.

Definition at line 189 of file VBContinuumSubtractor.h.

References calcFreqScale(), freqscale_p, hifreq_p, lofreq_p, and midfreq_p.

void casa::VBContinuumSubtractor::setTotNumChan ( const casacore::uInt tnc )

inline

Set the total number of input channels that will be looked at (including masked ones!)

Definition at line 205 of file VBContinuumSubtractor.h.

References totnumchan_p.

void casa::VBContinuumSubtractor::setTVIDebug ( bool debug )

inline

Definition at line 225 of file VBContinuumSubtractor.h.

References debug, and tvi_debug.

Member Data Documentation

casacore::PtrBlock<casacore::Vector<casacore::Bool> * > casa::VBContinuumSubtractor::chanmask_p

private

Definition at line 266 of file VBContinuumSubtractor.h.

casacore::Int casa::VBContinuumSubtractor::fitorder_p

private

VisBuffGroupAcc& vbga_p; // Holds the VisBuffers.

Definition at line 254 of file VBContinuumSubtractor.h.

Referenced by checkSize(), and getOrder().

casacore::Double casa::VBContinuumSubtractor::freqscale_p

private

Definition at line 259 of file VBContinuumSubtractor.h.

Referenced by setScalingFreqs().

casacore::Double casa::VBContinuumSubtractor::hifreq_p

private

Definition at line 257 of file VBContinuumSubtractor.h.

Referenced by calcFreqScale(), getHighFreq(), and setScalingFreqs().

casacore::Double casa::VBContinuumSubtractor::lofreq_p

private

Definition at line 256 of file VBContinuumSubtractor.h.

Referenced by getLowFreq(), and setScalingFreqs().

casacore::Int casa::VBContinuumSubtractor::maxAnt_p

private

Definition at line 260 of file VBContinuumSubtractor.h.

Referenced by getMaxAntNum(), hashFunction(), and setNAnt().

casacore::Double casa::VBContinuumSubtractor::midfreq_p

private

Definition at line 258 of file VBContinuumSubtractor.h.

Referenced by calcFreqScale(), and setScalingFreqs().

casacore::uInt casa::VBContinuumSubtractor::ncorr_p

private

Definition at line 263 of file VBContinuumSubtractor.h.

Referenced by checkSize().

casacore::uInt casa::VBContinuumSubtractor::nHashes_p

private

used with the fits.

-1 if not ready.

Definition at line 262 of file VBContinuumSubtractor.h.

Referenced by checkSize(), and setNAnt().

casacore::uInt casa::VBContinuumSubtractor::totnumchan_p

private

Definition at line 264 of file VBContinuumSubtractor.h.

Referenced by getTotNumChan(), and setTotNumChan().

bool casa::VBContinuumSubtractor::tvi_debug

private

Definition at line 268 of file VBContinuumSubtractor.h.

Referenced by setTVIDebug().

The documentation for this class was generated from the following file:

casa/code/msvis/MSVis/VBContinuumSubtractor.h

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Intended use:

Review Status

Prerequisite

Etymology

Synopsis

Example

Motivation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation