casa::LELUnaryConst< T > Class Template Reference

This LEL class handles scalar (unary) constants. More...

#include <LELUnary.h>

Inheritance diagram for casa::LELUnaryConst< T >:

List of all members.

Public Member Functions
	LELUnaryConst ()
	Default constructor creates a scalar with a false mask.
	LELUnaryConst (const T val)
	Constructor takes a scalar.
	~LELUnaryConst ()
	Destructor does nothing.
virtual void	eval (LELArray< T > &result, const Slicer &section) const
	Evaluate the expression.
virtual LELScalar< T >	getScalar () const
	Evaluate the scalar expression (get the constant)
virtual Bool	prepareScalarExpr ()
	Do further preparations (e.g.
virtual String	className () const
	Get class name.
Private Attributes
LELScalar< T >	val_p

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Detailed Description

template<class T>
class casa::LELUnaryConst< T >

This LEL class handles scalar (unary) constants.

Intended use:

Internal

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Prerequisite

• Lattice
• LatticeExpr
• LatticeExprNode
• LELInterface
• LELUnaryEnums

Etymology

This derived LEL letter class handles scalar (unary) constants

Synopsis

This LEL letter class is derived from LELInterface. It is used to construct LEL objects that represent scalars constants. They can be of type Float,Double,Complex,DComplex and Bool.

A description of the implementation details of the LEL classes can be found in Note 216

Example

Examples are not very useful as the user would never use these classes directly. Look in LatticeExprNode.cc to see how it invokes these classes. Examples of how the user would indirectly use this class (through the envelope) are:

    IPosition shape(2,5,10);
    ArrayLattice<Float> x(shape); x.set(1.0);
    ArrayLattice<Float> y(shape);
    ArrayLattice<Float> z(shape); 
    y.copyData(x+2.0);                 // y = x + 2.0
    z.copyData(True);                  // z = True

Motivation

Constants are a basic mathematical expression.

Definition at line 95 of file LELUnary.h.

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Constructor & Destructor Documentation

template<class T >

casa::LELUnaryConst< T >::LELUnaryConst

(

)

Default constructor creates a scalar with a false mask.

template<class T >

casa::LELUnaryConst< T >::LELUnaryConst

(

const T

val

)

Constructor takes a scalar.

template<class T >

casa::LELUnaryConst< T >::~LELUnaryConst

(

)

Destructor does nothing.

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Member Function Documentation

template<class T >

virtual String casa::LELUnaryConst< T >::className

(

)

const [virtual]

Get class name.

Implements casa::LELInterface< T >.

template<class T >

virtual void casa::LELUnaryConst< T >::eval	(	LELArray< T > &	result,
		const Slicer &	section
	)		const [virtual]

Evaluate the expression.

This throws an exception, since only a scalar can be returned.

Implements casa::LELInterface< T >.

template<class T >

virtual LELScalar<T> casa::LELUnaryConst< T >::getScalar

(

)

const [virtual]

Evaluate the scalar expression (get the constant)

Implements casa::LELInterface< T >.

template<class T >

virtual Bool casa::LELUnaryConst< T >::prepareScalarExpr

(

)

[virtual]

Do further preparations (e.g.

optimization) on the expression.

Implements casa::LELInterface< T >.

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Member Data Documentation

template<class T >

LELScalar<T> casa::LELUnaryConst< T >::val_p [private]

Definition at line 126 of file LELUnary.h.

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

• casacore/lattices/Lattices/LELUnary.h