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casacore::LELUnaryConst< T > Class Template Reference

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

#include <LELUnary.h>

Inheritance diagram for casacore::LELUnaryConst< T >:
casacore::LELInterface< T >

Public Member Functions

 LELUnaryConst ()
 Default constructor creates a scalar with a false mask. More...
 
 LELUnaryConst (const T val)
 Constructor takes a scalar. More...
 
 ~LELUnaryConst ()
 Destructor does nothing. More...
 
virtual void eval (LELArray< T > &result, const Slicer &section) const
 Evaluate the expression. More...
 
virtual LELScalar< T > getScalar () const
 Evaluate the scalar expression (get the constant) More...
 
virtual Bool prepareScalarExpr ()
 Do further preparations (e.g. More...
 
virtual String className () const
 Get class name. More...
 
- Public Member Functions inherited from casacore::LELInterface< T >
virtual ~LELInterface ()
 Virtual destructor. More...
 
virtual void evalRef (LELArrayRef< T > &result, const Slicer &section) const
 
LELArray< T > getArray () const
 Get the result of an array subexpression. More...
 
Bool isScalar () const
 Is the result of evaluating this expression a scalar ? More...
 
const IPositionshape () const
 Get the shape of the expression result. More...
 
const LELAttributegetAttribute () const
 Get expression attribute. More...
 
virtual Bool lock (FileLocker::LockType, uInt nattempts)
 Handle locking/syncing of the parts of a lattice expression. More...
 
virtual void unlock ()
 
virtual Bool hasLock (FileLocker::LockType) const
 
virtual void resync ()
 

Private Attributes

LELScalar< T > val_p
 

Additional Inherited Members

- Static Public Member Functions inherited from casacore::LELInterface< T >
static Bool replaceScalarExpr (CountedPtr< LELInterface< T > > &expr)
 If the given expression is a valid scalar, replace it by its result. More...
 
- Protected Member Functions inherited from casacore::LELInterface< T >
void setAttr (const LELAttribute &attrib)
 Set the expression attributes of this object. More...
 

Detailed Description

template<class T>
class casacore::LELUnaryConst< T >

This LEL class handles scalar (unary) constants.

Intended use:

Internal

Review Status

Date Reviewed:
yyyy/mm/dd

Prerequisite

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 96 of file LELUnary.h.

Constructor & Destructor Documentation

template<class T >
casacore::LELUnaryConst< T >::LELUnaryConst ( )

Default constructor creates a scalar with a false mask.

template<class T >
casacore::LELUnaryConst< T >::LELUnaryConst ( const T  val)

Constructor takes a scalar.

template<class T >
casacore::LELUnaryConst< T >::~LELUnaryConst ( )

Destructor does nothing.

Member Function Documentation

template<class T >
virtual String casacore::LELUnaryConst< T >::className ( ) const
virtual

Get class name.

Implements casacore::LELInterface< T >.

template<class T >
virtual void casacore::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 casacore::LELInterface< T >.

template<class T >
virtual LELScalar<T> casacore::LELUnaryConst< T >::getScalar ( ) const
virtual

Evaluate the scalar expression (get the constant)

Implements casacore::LELInterface< T >.

template<class T >
virtual Bool casacore::LELUnaryConst< T >::prepareScalarExpr ( )
virtual

Do further preparations (e.g.

optimization) on the expression.

Implements casacore::LELInterface< T >.

Member Data Documentation

template<class T >
LELScalar<T> casacore::LELUnaryConst< T >::val_p
private

Definition at line 127 of file LELUnary.h.


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