casacore::LELFunctionDouble Class Reference

This LEL class handles numerical functions whose return type is a Double. More...

#include <LELFunction.h>

Inheritance diagram for casacore::LELFunctionDouble:

Public Member Functions
	LELFunctionDouble (const LELFunctionEnums::Function function, const Block< LatticeExprNode > &expr)
	Constructor takes operation and left and right expressions to be operated upon. More...
	~LELFunctionDouble ()
	Destructor. More...
virtual void	eval (LELArray< Double > &result, const Slicer &section) const
	Recursively evaluate the expression. More...
virtual LELScalar< Double >	getScalar () const
	Recursively evaluate the scalar expression. 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< Double >
virtual	~LELInterface ()
	Virtual destructor. More...
virtual void	evalRef (LELArrayRef< Double > &result, const Slicer &section) const
LELArray< Double >	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 Member Functions
uInt	nMaskedElements (const LatticeExprNode &) const
	Count number of masked elements in a LatticeExprNode. More...
uInt	nMaskedOn (const Array< Bool > &mask) const

Private Attributes
LELFunctionEnums::Function	function_p
Block< LatticeExprNode >	arg_p

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

Detailed Description

This LEL class handles numerical functions whose return type is a Double.

Intended use:

Internal

Review Status

Date Reviewed:

yyyy/mm/dd

Prerequisite

• Lattice
• LatticeExpr
• LatticeExprNode
• LELInterface
• LELFunctionEnums

Etymology

This derived LEL letter class handles numerical functions (arbitrary number of arguments) which return a Double

Synopsis

This LEL letter class is derived from LELInterface. It is used to construct LEL objects that apply numerical functions of arbitrary number of arguments (but only 1 or 2 arguments currently implemented) to Lattice expressions. They operate on Double or DComplex Lattices and return a Double. The available C++ functions are min,max,pow,atan2,fmod,abs,arg,real,imag with equivalents in the enum of MIN,MAX,POW,ATAN2,FMOD,ABS,ARG,REAL, and IMAG.

There are also two other functions for which the input Lattice expression type must be a Bool. These are ntrue,nfalse with equivalents in the enum of NTRUE and NFALSE.

There is a further function for which the input Lattice expression type can be anything. This is nelements with equivalent in the enum of NELEM.

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<Bool> v(shape); v.set(True);
ArrayLattice<DComplex> w(shape); w.set(DComplex(2.0,3.0));
ArrayLattice<Double> x(shape); x.set(0.05);
ArrayLattice<Double> y(shape); y.set(2.0);
ArrayLattice<Double> z(shape); y.set(2.0);

z.copyData(min(x,y));                // z = min(x,y)
z.copyData(imag(w));                 // z = imag(w)
z.copyData(nelements(v));            // z = nelements(v)
z.copyData(ntrue(v));                // z = ntrue(v)

Motivation

Numerical functions are a basic mathematical expression.

Definition at line 531 of file LELFunction.h.

Constructor & Destructor Documentation

casacore::LELFunctionDouble::LELFunctionDouble	(	const LELFunctionEnums::Function	function,
		const Block< LatticeExprNode > &	expr
	)

Constructor takes operation and left and right expressions to be operated upon.

casacore::LELFunctionDouble::~LELFunctionDouble

(

)

Destructor.

Member Function Documentation

virtual String casacore::LELFunctionDouble::className ( ) const

virtual

Get class name.

Implements casacore::LELInterface< Double >.

virtual void casacore::LELFunctionDouble::eval ( LELArray< Double > &  result, const Slicer &  section  ) const

virtual

Recursively evaluate the expression.

Implements casacore::LELInterface< Double >.

virtual LELScalar<Double> casacore::LELFunctionDouble::getScalar ( ) const

virtual

Recursively evaluate the scalar expression.

Implements casacore::LELInterface< Double >.

virtual Bool casacore::LELFunctionDouble::hasLock ( FileLocker::LockType  ) const

virtual

Reimplemented from casacore::LELInterface< Double >.

virtual Bool casacore::LELFunctionDouble::lock ( FileLocker::LockType  , uInt  nattempts  )

virtual

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

Reimplemented from casacore::LELInterface< Double >.

uInt casacore::LELFunctionDouble::nMaskedElements ( const LatticeExprNode &  ) const

private

Count number of masked elements in a LatticeExprNode.

uInt casacore::LELFunctionDouble::nMaskedOn ( const Array< Bool > &  mask ) const

private

virtual Bool casacore::LELFunctionDouble::prepareScalarExpr ( )

virtual

Do further preparations (e.g.

optimization) on the expression.

Implements casacore::LELInterface< Double >.

virtual void casacore::LELFunctionDouble::resync ( )

virtual

Reimplemented from casacore::LELInterface< Double >.

virtual void casacore::LELFunctionDouble::unlock ( )

virtual

Reimplemented from casacore::LELInterface< Double >.

Member Data Documentation

Block<LatticeExprNode> casacore::LELFunctionDouble::arg_p

private

Definition at line 572 of file LELFunction.h.

LELFunctionEnums::Function casacore::LELFunctionDouble::function_p

private

Definition at line 571 of file LELFunction.h.

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

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