This LEL class handles relational binary numerical operators. More...

#include <LELBinary.h>

Inheritance diagram for casa::LELBinaryCmp< T >:

Public Member Functions
	LELBinaryCmp (const LELBinaryEnums::Operation op, const CountedPtr< LELInterface< T > > &pLeftExpr, const CountedPtr< LELInterface< T > > &pRightExpr)
	Constructor takes operation and left and right expressions to be operated upon.
	~LELBinaryCmp ()
	Destructor.
virtual void	eval (LELArray< Bool > &result, const Slicer &section) const
	Recursively evaluate the expression.
virtual LELScalar< Bool >	getScalar () const
	Recursively evaluate the scalar expression.
virtual Bool	prepareScalarExpr ()
	Do further preparations (e.g.
virtual String	className () const
	Get class name.
virtual Bool	lock (FileLocker::LockType, uInt nattempts)
	Handle locking/syncing of a lattice in a lattice expression.
virtual void	unlock ()
virtual Bool	hasLock (FileLocker::LockType) const
virtual void	resync ()
Private Attributes
LELBinaryEnums::Operation	op_p

CountedPtr< LELInterface< T > >	pLeftExpr_p
CountedPtr< LELInterface< T > >	pRightExpr_p

Detailed Description

template<class T>
class casa::LELBinaryCmp< T >

This LEL class handles relational binary numerical operators.

Intended use:

Internal

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Prerequisite

Etymology

This derived LEL letter class handles relational numerical binary operators

Synopsis

This LEL letter class is derived from LELInterface. It is used to construct LEL objects that apply relational numerical binary operators to Lattice expressions. They operate on numerical (Float,Double,Complex,DComplex) Lattice expressions and result in a Bool. The available C++ operators are ==,!=>,>=,<,<=, with equivalents in the enum of EQ, NE, GT, GE, LT, and LE

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); y.set(2.0);
    ArrayLattice<Bool> z(shape); 
    z.copyData(x==y);                // z = x == y;
    z.copyData(x!=y);                // z = x != y;
    z.copyData(x>y);                 // z = x > y;
    z.copyData(x>=y);                // z = x >= y;
    z.copyData(x<y);                 // z = x < y;
    z.copyData(x<=y);                // z = x <= y;

Motivation

Numerical relational binary operations are a basic mathematical expression.

Definition at line 209 of file LELBinary.h.

Constructor & Destructor Documentation

template<class T >

casa::LELBinaryCmp< T >::LELBinaryCmp	(	const LELBinaryEnums::Operation	op,
		const CountedPtr< LELInterface< T > > &	pLeftExpr,
		const CountedPtr< LELInterface< T > > &	pRightExpr
	)