PBMath1DGauss is a 1-D Gaussian Primary Beam. More...

#include <PBMath1DGauss.h>

Inheritance diagram for casa::PBMath1DGauss:

Public Member Functions
	PBMath1DGauss ()
	PBMath1DGauss (Quantity halfWidth, Quantity maxRad, Quantity refFreq, Bool isThisVP=False, BeamSquint squint=BeamSquint(MDirection(Quantity(0.0,"deg"), Quantity(0.0,"deg"), MDirection::Ref(MDirection::AZEL)), Quantity(1.0,"GHz")), Bool useSymmetricBeam=False)
	Instantiation from arguments; default = no squint squint is the offset from pointing center if the Stokes R beam useSymmetricBeam forces a fit to the squinted beam width = Half-Width-Half-max maxRad = half-width at zero intensity.
PBMath1DGauss &	operator= (const PBMath1DGauss &other)
	Instantiation from a row in the Beam subTable PBMath1DGauss(const Table& BeamSubTable, Int row, Bool useSymmetricBeam=False);.
	~PBMath1DGauss ()
	Clone the object CountedPtr<PBMathInterface> clone();.
PBMathInterface::PBClass	whichPBClass ()
	Get the type of PB this is.
void	summary (Int nValues=0)
	Flush the construction parameters to disk Bool flushToTable(Table& beamSubTable, Int iRow);.
Protected Member Functions
void	fillPBArray ()
	Fill in vp_p array from construction parameters.
Private Attributes
Quantity	halfWidth_p

Detailed Description

PBMath1DGauss is a 1-D Gaussian Primary Beam.

Intended use:

Public interface

Prerequisite

PBMathInterface class
PBMath1D class

Etymology

PBMath1DGauss: derived from PBMath1D, implements a gaussian PB and VP

Synopsis

See PBMath1D for a general synopsis of the 1D PB types. Remember that we construct based on Voltage Patterns rather than primary beams. The Voltage Pattern HWHM width will be sqrt(2) times larger than the Primary Beam HWHM.

VP(x) = exp( - ( x/HWHM )**2 * log(2) ), out to maximumRadius

Example

       PBMath1DGauss myPB  (Quantity(1.0, "'"),
                            Quantity(3.0, "'"),
                            Quantity(1.0, "GHz"),
                            BeamSquint(MDirection(Quantity(2.0, "\""),
                                                            Quantity(0.0, "\""),
                                                            MDirection::Ref(MDirection::AZEL)),
                                       Quantity(2.0, "GHz")),
                            False);

Motivation

All of the 1-D PB types have everything in common except for the details of their parameterization. This lightweight class deals with those differences: construction, filling the PBArray from construction parameters, and flushing to disk. BIMA uses a Gaussian PB.

To Do

constructor from a MS beam subtable
flush to MS beam subtable

Definition at line 95 of file PBMath1DGauss.h.

Constructor & Destructor Documentation

casa::PBMath1DGauss::PBMath1DGauss ( )

casa::PBMath1DGauss::PBMath1DGauss	(	Quantity	halfWidth,
		Quantity	maxRad,
		Quantity	refFreq,
		Bool	isThisVP = `False`,
		BeamSquint	squint = `BeamSquint(MDirection(Quantity(0.0,"deg"), Quantity(0.0,"deg"), MDirection::Ref(MDirection::AZEL)), Quantity(1.0,"GHz"))`,
		Bool	useSymmetricBeam = `False`
	)

Instantiation from arguments; default = no squint squint is the offset from pointing center if the Stokes R beam useSymmetricBeam forces a fit to the squinted beam width = Half-Width-Half-max maxRad = half-width at zero intensity.

casa::PBMath1DGauss::~PBMath1DGauss ( )

Clone the object CountedPtr<PBMathInterface> clone();.

destructor