casacore::MeasEngine< M > Class Template Reference

Templated base class for the TaQL UDF conversion engines. More...

#include <MeasEngine.h>

Inheritance diagram for casacore::MeasEngine< M >:

Public Member Functions
	MeasEngine ()
virtual	~MeasEngine ()
M::Types	refType () const
	Get the reference type. More...
Bool	handleMeasType (const TENShPtr &operand, Bool doThrow)
	Handle a doppler reference type. More...
Record	makeAttributes (typename M::Types refType, Int valueType=1) const
	Make the expression result attributes. More...
Public Member Functions inherited from casacore::BaseEngine
	BaseEngine ()
virtual	~BaseEngine ()
void	adaptForConstant (const IPosition &shapeConstant, uInt nvalues=0)
	Adapt the output shape and dimensionality for possible constant values. More...
void	extendBase (const BaseEngine &, Bool removeFirstAxis=False)
	Extend the shape (if not empty) with the engine's shape. More...
const IPosition &	shape () const
	Get the output shape. More...
Int	ndim () const
	Get the output dimensionality. More...
const Unit &	unit () const
	Get the unit of the function's result. More...
const Unit &	inUnit () const
	Get the unit of the expression. More...
Bool	isConstant () const
	Tell if the expression is constant. More...

Protected Member Functions
void	handleMeasArray (const TENShPtr &operand)
	Handle the operand representing an array of Meas values. More...
void	handleConstant (const TENShPtr &operand)
	Handle a constant Meas value. More...
virtual void	handleValues (TableExprNode &operand, const TableExprId &id, Array< M > &positions)=0
	Let a derive class handle the values. More...
Protected Member Functions inherited from casacore::BaseEngine
virtual void	deriveAttr (const Unit &unit, Int nval)
	Let a derived class derive its attributes. More...
virtual void	setValueType (Int valueType)
	Let a derived class set its value type. More...
virtual String	stripMeasType (const String &type)
	Let a derived class strip part of the reference type. More...

Protected Attributes
Array< M >	itsConstants
M::Types	itsRefType
ScalarMeasColumn< M >	itsMeasScaCol
ArrayMeasColumn< M >	itsMeasArrCol
Protected Attributes inherited from casacore::BaseEngine
Bool	itsIsConst
IPosition	itsShape
Int	itsNDim
Unit	itsInUnit
Unit	itsOutUnit
TableExprNode	itsExprNode

Detailed Description

template<typename M>
class casacore::MeasEngine< M >

Templated base class for the TaQL UDF conversion engines.

Intended use:

Public interface

Review Status

Test programs:

tMeas

Prerequisite

• BaseEngine

Synopsis

DopplerEngine defines Engines (user defined functions) that can be used in TaQL to convert Measures for dopplers. In this way such derived values appear to be ordinary TaQL functions.

Doppler conversions require a MeasFrame containing sky direction, epoch and position on earth. In TaQL these functions can be called like:

meas.rv ('TOPO', 1 'm/s', 'LSRK', 'CasA', date(),
[1e6m,1e6m,1e6m], 'WGS84')

which converts the dopplers from LSRK to TOPO.

• toref is a single constant string.
• pos can have various value types. A single numeric array is a series of RA,DEC in J2000. If given as a set, the last argument of the set can be the reference types of the values in the set. The values can be strings (indicating planetary objects) or value pairs giving lon,lat. The default reference type is J2000.

All such functions return data with type double and unit Hz.

Dopplers can be given like: [v1,v2,...], fromRef where fromRef is the reference type.

A doppler can also be a table column which usually knows its type. It can also be an expression (e.g. DOPPLER[0,]) which also knows the type.

Motivation

It makes it possible to handle measures in TaQL.

Definition at line 92 of file MeasEngine.h.

Constructor & Destructor Documentation

template<typename M>

casacore::MeasEngine< M >::MeasEngine ( )

inline

Definition at line 95 of file MeasEngine.h.

template<typename M>

virtual casacore::MeasEngine< M >::~MeasEngine ( )

virtual

Member Function Documentation

template<typename M>

void casacore::MeasEngine< M >::handleConstant ( const TENShPtr &  operand )

protected

Handle a constant Meas value.

template<typename M>

void casacore::MeasEngine< M >::handleMeasArray ( const TENShPtr &  operand )

protected

Handle the operand representing an array of Meas values.

template<typename M>

Bool casacore::MeasEngine< M >::handleMeasType	(	const TENShPtr &	operand,
		Bool	doThrow
	)

Handle a doppler reference type.

If the reference type is invalid, an exception is only thrown if doThrow=True. In this way a string argument can be a source name for a direction.

template<typename M>

virtual void casacore::MeasEngine< M >::handleValues ( TableExprNode &  operand, const TableExprId &  id, Array< M > &  positions  )

protectedpure virtual

Let a derive class handle the values.

Implemented in casacore::EarthMagneticEngine, casacore::DirectionEngine, casacore::PositionEngine, casacore::FrequencyEngine, casacore::RadialVelocityEngine, casacore::DopplerEngine, and casacore::EpochEngine.

template<typename M>

Record casacore::MeasEngine< M >::makeAttributes	(	typename M::Types	refType,
		Int	valueType = 1
	)		const

Make the expression result attributes.

template<typename M>

M::Types casacore::MeasEngine< M >::refType ( ) const

inline

Get the reference type.

Definition at line 102 of file MeasEngine.h.

Member Data Documentation

template<typename M>

Array<M> casacore::MeasEngine< M >::itsConstants

protected

Definition at line 128 of file MeasEngine.h.

template<typename M>

ArrayMeasColumn<M> casacore::MeasEngine< M >::itsMeasArrCol

protected

Definition at line 131 of file MeasEngine.h.

template<typename M>

ScalarMeasColumn<M> casacore::MeasEngine< M >::itsMeasScaCol

protected

Definition at line 130 of file MeasEngine.h.

template<typename M>

M::Types casacore::MeasEngine< M >::itsRefType

protected

Definition at line 129 of file MeasEngine.h.

Referenced by casacore::MeasEngine< MEpoch >::refType().

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

• casa/casacore/meas/MeasUDF/MeasEngine.h