StokesConverter converts any set of polarizations into any other one. More...

#include <StokesConverter.h>

Public Member Functions
	StokesConverter ()
	default constructor, does not set up a conversion
	StokesConverter (const Vector< Int > &out, const Vector< Int > &in, Bool rescale=False)
	Set up a conversion from in to out.
	~StokesConverter ()
	desctructor
	StokesConverter (const StokesConverter &other)
	Copy constructor.
StokesConverter &	operator= (const StokesConverter &other)
	Assignment,.
void	setConversion (const Vector< Int > &out, const Vector< Int > &in, Bool rescale=False)
	Change or Set the conversion.
void	convert (Array< Complex > &out, const Array< Complex > &in) const
	convert data, first dimension of input must match that of the input conversion vector used to set up the conversion.
void	convert (Array< Bool > &out, const Array< Bool > &in) const
	convert flags, first dimension of input must match that of the input conversion vector used to set up the conversion.
void	convert (Array< Float > &out, const Array< Float > &in, Bool sigma=False) const
	convert weights, first dimension of input must match that of the input conversion vector used to set up the conversion.
void	invert (Array< Bool > &out, const Array< Bool > &in) const
	invert flags, first dimension of input must match that of the output conversion vector used to set up the conversion.
Protected Member Functions
void	initConvMatrix ()
	initialize the polarization conversion matrix
Private Attributes
Vector< Int >	in_p
Vector< Int >	out_p
Bool	rescale_p
Matrix< Complex >	conv_p
Matrix< Complex >	iquvConv_p
Bool	doIQUV_p
Matrix< Bool >	flagConv_p
Matrix< Float >	wtConv_p
Matrix< Complex >	polConv_p

Detailed Description

StokesConverter converts any set of polarizations into any other one.

Intended use:

Public interface

Review Status

Date Reviewed:: yyyy/mm/dd
Test programs:: tStokesConverter

Prerequisite

Stokes

Etymology

StokesConverter is a class that converts Stokes Parameters

Synopsis

This class is used to convert polarizations from one system to another. First the conversion wanted is specified and then large blocks of data can be converted.

Example

    // create converter
       StokesConverter sc;
       Vector<Int> out(7),in(4);
    // set the input polarizations   
       in(0)=Stokes::RR;
       in(1)=Stokes::LL;
       in(2)=Stokes::RL;
       in(3)=Stokes::LR;
    // set the required output  
       out(0)=Stokes::I;
       out(1)=Stokes::Q;
       out(2)=Stokes::U;
       out(3)=Stokes::V;
       out(4)=Stokes::Ptotal;
       out(5)=Stokes::Pangle;
       out(6)=Stokes::PFlinear;
    // initialize the conversion engine   
       sc.setConversion(out,in);
    // set up some test data   
       Vector<Complex> datain(4),dataout(7);
       datain(0)=1.0;
       datain(1)=0.9;
       datain(2)=0.3;
       datain(3)=0.2;
    // convert the data   
       sc.convert(dataout,datain);

Motivation

Polarization conversion is needed in various places. It makes sense to provide all conversion in one place.

Thrown Exceptions

To Do

cope with incomplete input polarizations sensibly
decide what to do about factor 2 between I and RR/LL,XX/YY etc.

Definition at line 109 of file StokesConverter.h.

Constructor & Destructor Documentation

casa::StokesConverter::StokesConverter ( )

default constructor, does not set up a conversion

casa::StokesConverter::StokesConverter	(	const Vector< Int > &	out,
		const Vector< Int > &	in,
		Bool	rescale = `False`
	)

Set up a conversion from in to out.

The in and out vectors contain a list of polarization present/wanted in that order. The in vector should match the data to convert. (CORR_TYPE column in SPECTRAL_WINDOW table contains this info) The rescale option will correct for crosscorrelation data that has been scaled to the level Stokes I (common practice in radioastronomy: even though officially I=XX+YY, in practice we need to do I=(XX+YY)/2, set rescale to True to do the latter).

casa::StokesConverter::~StokesConverter ( )

desctructor

casa::StokesConverter::StokesConverter ( const StokesConverter & other )

Copy constructor.

Member Function Documentation

void casa::StokesConverter::convert	(	Array< Complex > &	out,
		const Array< Complex > &	in
	)		const

convert data, first dimension of input must match that of the input conversion vector used to set up the conversion.

Output is resized as needed.

void casa::StokesConverter::convert	(	Array< Bool > &	out,
		const Array< Bool > &	in
	)		const

convert flags, first dimension of input must match that of the input conversion vector used to set up the conversion.

Output is resized as needed. All output depending on a flagged input will be flagged.

void casa::StokesConverter::convert	(	Array< Float > &	out,
		const Array< Float > &	in,
		Bool	sigma = `False`
	)		const

convert weights, first dimension of input must match that of the input conversion vector used to set up the conversion.

Output is resized as needed. Set sigma to True when converting sigma's using this routine.

void casa::StokesConverter::initConvMatrix ( ) [protected]

initialize the polarization conversion matrix

void casa::StokesConverter::invert	(	Array< Bool > &	out,
		const Array< Bool > &	in
	)		const

invert flags, first dimension of input must match that of the output conversion vector used to set up the conversion.

Output is resized as needed. All output depending on a flagged input will be flagged. This does the inverse operation of convert, allowing flagging of converted data to be transferred back to the original data.

StokesConverter& casa::StokesConverter::operator= ( const StokesConverter & other )

Assignment,.