casacore::LELFunctionND< T > Class Template Reference

This LEL class handles functions with a variable number of arguments. More...

#include <LELFunction.h>

Inheritance diagram for casacore::LELFunctionND< T >:

Public Member Functions
	LELFunctionND (const LELFunctionEnums::Function function, const Block< LatticeExprNode > &expr)
	Constructor takes operation and expressions to be operated upon.
	~LELFunctionND ()
	Destructor.
virtual void	eval (LELArray< T > &result, const Slicer &section) const
	Recursively evaluate the expression.
virtual LELScalar< T >	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
LELFunctionEnums::Function	function_p
Block< LatticeExprNode >	arg_p

Detailed Description

template<class T>
class casacore::LELFunctionND< T >

This LEL class handles functions with a variable number of arguments.

Intended use:

Internal

Review Status

Date Reviewed:: yyyy/mm/dd

Prerequisite

Etymology

This derived LEL letter class handles numerical functions (arbitrary number of arguments) which return any data type

Synopsis

This templated LEL letter class is derived from LELInterface. It is used to construct LEL objects that apply functions of arbitrary number of arguments to Lattice expressions. They operate lattices with any type and return the same type. The available C++ function is iif with equivalents in the enum of IIF.

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<Complex> w(shape); w.set(Complex(2.0,3.0));
 ArrayLattice<Float> x(shape); x.set(0.05);
 ArrayLattice<Float> y(shape); y.set(2.0);
 ArrayLattice<Float> z(shape); y.set(2.0);
 
 z.copyData(iif(x==0, y, x));

Copy x to z, but where x==0, take the correpsonding element from y. b