casacore::LELConvert< T, F > Class Template Reference

Class to convert a LEL node from one numerical type to another. More...

#include <LELConvert.h>

Inheritance diagram for casacore::LELConvert< T, F >:

Public Member Functions
	LELConvert (const CountedPtr< LELInterface< F > > &expr)
	Constructor. More...
	~LELConvert ()
	Destructor does nothing. More...
virtual void	eval (LELArray< T > &result, const Slicer &section) const
	Recursively evaluate the expression. More...
virtual LELScalar< T >	getScalar () const
	Recursively evaluate the scalar. More...
virtual Bool	prepareScalarExpr ()
	Do further preparations (e.g. More...
virtual String	className () const
	Get class name. More...
virtual Bool	lock (FileLocker::LockType, uInt nattempts)
	Handle locking/syncing of a lattice in a lattice expression. More...
virtual void	unlock ()
virtual Bool	hasLock (FileLocker::LockType) const
virtual void	resync ()
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 IPosition &	shape () const
	Get the shape of the expression result. More...
const LELAttribute &	getAttribute () const
	Get expression attribute. More...

Private Attributes
CountedPtr< LELInterface< F > >	pExpr_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 F>
class casacore::LELConvert< T, F >

Class to convert a LEL node from one numerical type to another.

Intended use:

Internal

Review Status

Date Reviewed:

yyyy/mm/dd

Prerequisite

• Lattice
• LatticeExpr
• LatticeExprNode
• LELInterface

Etymology

This derived LEL letter class handles numerical type conversions

Synopsis

This LEL letter class is derived from LELInterface. It is used to construct LEL objects that know how to convert between numerical types, such as Double to Float. They operate on numerical Lattices and return a numerical Lattice. The LELConvert object is embedded in the tree, and the conversion actually happens at tree evaluation time.

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. An example of how the user would indirectly use this class (through the envelope) is:

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

The LELConvert class is embedded in the tree at construction time so as to handle the conversion from Float to Double at evaluation time

Motivation

We needed to be able to handle mixed types in the LEL classes

Definition at line 95 of file LELConvert.h.

Constructor & Destructor Documentation

template<class T , class F >

casacore::LELConvert< T, F >::LELConvert

(

const CountedPtr< LELInterface< F > > &

expr

)

Constructor.

<F> is the type we are coinverting from. <T> is the type we are converting to.

template<class T , class F >

casacore::LELConvert< T, F >::~LELConvert

(

)

Destructor does nothing.

Member Function Documentation

template<class T , class F >

virtual String casacore::LELConvert< T, F >::className ( ) const

virtual

Get class name.

Implements casacore::LELInterface< T >.

template<class T , class F >

virtual void casacore::LELConvert< T, F >::eval ( LELArray< T > &  result, const Slicer &  section  ) const

virtual

Recursively evaluate the expression.

Implements casacore::LELInterface< T >.

template<class T , class F >

virtual LELScalar<T> casacore::LELConvert< T, F >::getScalar ( ) const

virtual

Recursively evaluate the scalar.

Implements casacore::LELInterface< T >.

template<class T , class F >

virtual Bool casacore::LELConvert< T, F >::hasLock ( FileLocker::LockType  ) const

virtual

Reimplemented from casacore::LELInterface< T >.

template<class T , class F >

virtual Bool casacore::LELConvert< T, F >::lock ( FileLocker::LockType  , uInt  nattempts  )

virtual

Handle locking/syncing of a lattice in a lattice expression.

Reimplemented from casacore::LELInterface< T >.

template<class T , class F >

virtual Bool casacore::LELConvert< T, F >::prepareScalarExpr ( )

virtual

Do further preparations (e.g.

optimization) on the expression.

Implements casacore::LELInterface< T >.

template<class T , class F >

virtual void casacore::LELConvert< T, F >::resync ( )

virtual

Reimplemented from casacore::LELInterface< T >.

template<class T , class F >

virtual void casacore::LELConvert< T, F >::unlock ( )

virtual

Reimplemented from casacore::LELInterface< T >.

Member Data Documentation

template<class T , class F >

CountedPtr<LELInterface<F> > casacore::LELConvert< T, F >::pExpr_p

private

Definition at line 128 of file LELConvert.h.

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

• casa/casacore/lattices/LEL/LELConvert.h