Class to allow C++ expressions involving lattices. More...

#include <LatticeExpr.h>

Inheritance diagram for casacore::LatticeExpr< T >:

Public Member Functions
	LatticeExpr ()
	Default constructor. More...

	LatticeExpr (const LatticeExprNode &expr)
	Constructor from an arbitrary LatticeExprNode expression object. More...

	LatticeExpr (const LatticeExprNode &expr, const IPosition &latticeShape)

	LatticeExpr (const LatticeExpr< T > &other)
	Copy constructor (reference semantics) More...

virtual	~LatticeExpr ()
	Destructor, does nothing. More...

LatticeExpr< T > &	operator= (const LatticeExpr< T > &other)
	Assignment (reference semantics) More...

virtual MaskedLattice< T > *	cloneML () const
	Make a copy of the derived object (reference semantics). More...

virtual Bool	isMasked () const
	Has the object really a mask? More...

virtual const LatticeRegion *	getRegionPtr () const
	Get the region used (always returns 0). More...

virtual Bool	isWritable () const
	Returns False, as the LatticeExpr lattice is not writable. More...

virtual Bool	lock (FileLocker::LockType, uInt nattempts)
	Handle locking of the LatticeExpr which is delegated to all of its parts. More...

virtual void	unlock ()

virtual Bool	hasLock (FileLocker::LockType) const

virtual void	resync ()
	Resynchronize the Lattice object with the lattice file. More...

virtual IPosition	shape () const
	Returns the shape of the Lattice including all degenerate axes (i.e. More...

virtual IPosition	doNiceCursorShape (uInt maxPixels) const
	Return the best cursor shape. More...

virtual LELCoordinates	lelCoordinates () const
	Returns the coordinates of the lattice expression. More...

virtual Bool	doGetSlice (Array< T > &buffer, const Slicer &section)
	Do the actual get of the data. More...

virtual Bool	doGetMaskSlice (Array< Bool > &buffer, const Slicer &section)
	Do the actual get of the mask data. More...

virtual void	doPutSlice (const Array< T > &sourceBuffer, const IPosition &where, const IPosition &stride)
	An expression is not writable so this functions throws an exception. More...

virtual void	copyDataTo (Lattice< T > &to) const
	Copy the data from this lattice to the given lattice. More...

virtual void	handleMathTo (Lattice< T > &to, int oper) const
	Handle the Math operators (+=, -=, *=, /=). More...

template<>
void	handleMathTo (Lattice< Bool > &, int) const

Public Member Functions inherited from casacore::MaskedLattice< T >
	MaskedLattice ()
	Default constructor. More...

	MaskedLattice (const MaskedLattice< T > &)
	Copy constructor. More...

virtual	~MaskedLattice ()
	a virtual destructor is needed so that it will use the actual destructor in the derived class More...

virtual Lattice< T > *	clone () const
	Make a copy of the derived object (reference semantics). More...

virtual Bool	hasPixelMask () const
	Does the lattice have a pixelmask? The default implementation returns False. More...

virtual const Lattice< Bool > &	pixelMask () const
	Get access to the pixelmask. More...

virtual Lattice< Bool > &	pixelMask ()

const LatticeRegion &	region () const
	Get the region used. More...

Bool	getMask (COWPtr< Array< Bool > > &buffer, Bool removeDegenerateAxes=False) const
	Get the mask or a slice from the mask. More...

Bool	getMaskSlice (COWPtr< Array< Bool > > &buffer, const Slicer &section, Bool removeDegenerateAxes=False) const

Bool	getMaskSlice (COWPtr< Array< Bool > > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Bool	getMaskSlice (COWPtr< Array< Bool > > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

Bool	getMask (Array< Bool > &buffer, Bool removeDegenerateAxes=False)

Bool	getMaskSlice (Array< Bool > &buffer, const Slicer &section, Bool removeDegenerateAxes=False)

Bool	getMaskSlice (Array< Bool > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False)

Bool	getMaskSlice (Array< Bool > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False)

Array< Bool >	getMask (Bool removeDegenerateAxes=False) const

Array< Bool >	getMaskSlice (const Slicer &section, Bool removeDegenerateAxes=False) const

Array< Bool >	getMaskSlice (const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Array< Bool >	getMaskSlice (const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

Public Member Functions inherited from casacore::Lattice< T >
virtual	~Lattice ()
	a virtual destructor is needed so that it will use the actual destructor in the derived class More...

virtual DataType	dataType () const
	Get the data type of the lattice. More...

T	operator() (const IPosition &where) const
	Return the value of the single element located at the argument IPosition. More...

virtual T	getAt (const IPosition &where) const

virtual void	putAt (const T &value, const IPosition &where)
	Put the value of a single element. More...

Bool	get (COWPtr< Array< T > > &buffer, Bool removeDegenerateAxes=False) const
	Functions which extract an Array of values from a Lattice. More...

Bool	getSlice (COWPtr< Array< T > > &buffer, const Slicer &section, Bool removeDegenerateAxes=False) const

Bool	getSlice (COWPtr< Array< T > > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Bool	getSlice (COWPtr< Array< T > > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

Bool	get (Array< T > &buffer, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const Slicer &section, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False)

Array< T >	get (Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const Slicer &section, Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

void	putSlice (const Array< T > &sourceBuffer, const IPosition &where, const IPosition &stride)
	A function which places an Array of values within this instance of the Lattice at the location specified by the IPosition "where", incrementing by "stride". More...

void	putSlice (const Array< T > &sourceBuffer, const IPosition &where)

void	put (const Array< T > &sourceBuffer)

virtual void	set (const T &value)
	Set all elements in the Lattice to the given value. More...

virtual void	apply (T(*function)(T))
	Replace every element, x, of the Lattice with the result of f(x). More...

virtual void	apply (T(*function)(const T &))

virtual void	apply (const Functional< T, T > &function)

void	operator+= (const Lattice< T > &other)
	Add, subtract, multiple, or divide by another Lattice. More...

void	operator-= (const Lattice< T > &other)

void	operator*= (const Lattice< T > &other)

void	operator/= (const Lattice< T > &other)

virtual void	copyData (const Lattice< T > &from)
	Copy the data from the given lattice to this one. More...

virtual uInt	advisedMaxPixels () const
	This function returns the advised maximum number of pixels to include in the cursor of an iterator. More...

virtual LatticeIterInterface< T > *	makeIter (const LatticeNavigator &navigator, Bool useRef) const
	These functions are used by the LatticeIterator class to generate an iterator of the correct type for a specified Lattice. More...

Public Member Functions inherited from casacore::LatticeBase
virtual	~LatticeBase ()
	A virtual destructor is needed so that it will use the actual destructor in the derived class. More...

virtual String	imageType () const
	Get the image type (returns name of derived class). More...

virtual Bool	isPersistent () const
	Is the lattice persistent and can it be loaded by other processes as well? That is the case for a PagedArray or PagedImage and for an ImageExpr which does not use transient lattices or regions. More...

virtual Bool	isPaged () const
	Is the lattice paged to disk? The default implementation returns False. More...

virtual Bool	canReferenceArray () const
	Can the lattice data be referenced as an array section? That is the case for an ArrayLattice or a Temp/SubLattice using it. More...

virtual void	save (const String &fileName) const
	Save the image in an AipsIO file with the given name. More...

virtual void	flush ()
	Flush the data (but do not unlock). More...

virtual void	tempClose ()
	Temporarily close the lattice. More...

virtual void	reopen ()
	Explicitly reopen the temporarily closed lattice. More...

virtual String	name (Bool stripPath=False) const
	Return the name of the current Lattice object. More...

virtual uInt	ndim () const
	Return the number of axes in this Lattice. More...

virtual size_t	nelements () const
	Return the total number of elements in this Lattice. More...

size_t	size () const

Bool	conform (const LatticeBase &other) const
	Return a value of "True" if this instance of Lattice and 'other' have the same shape, otherwise returns a value of "False". More...

IPosition	niceCursorShape (uInt maxPixels) const
	Returns a recommended cursor shape for iterating through all the pixels in the Lattice. More...

IPosition	niceCursorShape () const

virtual Bool	ok () const
	Check class internals - used for debugging. More...

virtual uInt	maximumCacheSize () const
	Maximum cache size - not necessarily all used. More...

virtual void	setMaximumCacheSize (uInt howManyPixels)
	Set the maximum (allowed) cache size as indicated. More...

virtual void	setCacheSizeInTiles (uInt howManyTiles)
	Set the actual cache size for this Array to be big enough for the indicated number of tiles. More...

virtual void	setCacheSizeFromPath (const IPosition &sliceShape, const IPosition &windowStart, const IPosition &windowLength, const IPosition &axisPath)
	Set the cache size as to "fit" the indicated path. More...

virtual void	clearCache ()
	Clears and frees up the caches, but the maximum allowed cache size is unchanged from when setCacheSize was called. More...

virtual void	showCacheStatistics (ostream &os) const
	Report on cache success. More...

Private Member Functions
void	init (const LatticeExprNode &expr)
	Initialize the object from the expression. More...

Private Attributes
LatticeExprNode	expr_p

IPosition	shape_p

LELArray< T > *	lastChunkPtr_p

Slicer	lastSlicer_p

Additional Inherited Members
Protected Member Functions inherited from casacore::MaskedLattice< T >
MaskedLattice< T > &	operator= (const MaskedLattice< T > &)
	Assignment can only be used by derived classes. More...

Protected Member Functions inherited from casacore::Lattice< T >
	Lattice ()
	Define default constructor to satisfy compiler. More...

virtual void	handleMath (const Lattice< T > &from, int oper)
	Handle the Math operators (+=, -=, *=, /=). More...

	Lattice (const Lattice< T > &)
	Copy constructor and assignment can only be used by derived classes. More...

Lattice< T > &	operator= (const Lattice< T > &)

template<>
void	handleMathTo (Lattice< Bool > &, int) const

Protected Member Functions inherited from casacore::LatticeBase
	LatticeBase ()
	Define default constructor to be used by derived classes. More...

	LatticeBase (const LatticeBase &)
	Copy constructor and assignment can only be used by derived classes. More...

LatticeBase &	operator= (const LatticeBase &)

void	throwBoolMath () const
	Throw an exception for arithmetic on a Bool Lattice. More...

Detailed Description

template<class T>
class casacore::LatticeExpr< T >

Class to allow C++ expressions involving lattices.

Intended use:

Public interface

Review Status

Date Reviewed:: yyyy/mm/dd

Prerequisite

Etymology

The name is derived from the fact that this class provides an expression interface to the user which s/he may use to write C++ expressions involving Lattices.

Synopsis

This class provides an interface which allows the C++ programmer to enter expressions such as "sin(a)+b" where "a" and "b" are Lattices.

This class is termed an envelope class, and inside it are the letter classes which do the real work. In reality, the letter classes are actually accessed via a bridging class called LatticeExprNode, which exists to handle type conversions. The letter classes iterate through the Lattices and evaluate the expression for each chunk of the iteration (usually a tile shape).

It is in the LatticeExprNode class that all the available expression operations are defined, so you should look there to see what functionality is available.

A description of the implementation details of these classes can be found in Note 216

Example

ArrayLattice<Float>   f1(IPosition (2,nx,ny));
ArrayLattice<Float>   f2(IPosition (2,nx,ny));
f2.set(2.0);
f1.copyData(2*f2+f2);

In this example, the values of the pixels in Lattice f1 are set to the values resulting from the expression "2*f2 + f2" I.e. the expression is evaluated for each pixel in the Lattices

Note that : 1) the Lattice::copyData function is expecting a Lattice argument. 2) LatticeExpr inherits from Lattice and therefore a LatticeExpr object is a valid argument object type 3) The expression in the copyData call is automatically converted to a LatticeExprNode by the constructors and operators in LatticeExprNode 4) The LatticeExprNode object so created is automatically converted to a LatticeExpr by casting functions in LatticeExprNode.

Example

ArrayLattice<Float>   f1(IPosition (2,nx,ny));
ArrayLattice<Float>   f2(IPosition (2,nx,ny));
ArrayLattice<Double>  d(IPosition (2,nx,ny));
ArrayLattice<Complex> c(IPosition (2,nx,ny));
ArrayLattice<Bool>    b(IPosition (2,nx,ny));
f2.set(1.0); d.set(2.0); c.set(Complex(2.0,3.0)); b.set(True);
f1.copyData((3.5*f2) + (cos(d)) - (10/min(d,f2)*(-abs(c))*ntrue(b)) - (C::pi));

In this rather silly example, we fill Lattice "f1" with the result of the expression. The expression shows the use of constants, unary operations, binary operations, 1D and 2D functions. It also shows how mixed types can be handled. The output Lattice is a Float, whereas mixed into the expression are subexpressions involving Float, Double, Complex and Bool Lattices.

Motivation

The Lattice expression classes enable the C++ programmer much simpler handling of mathematical expressions involving lattices. In addition, these classes provide the infrastructure on top of which we can build an image calculator for Glish users

To Do

masks
regions

Definition at line 142 of file LatticeExpr.h.

Constructor & Destructor Documentation

template<class T>

casacore::LatticeExpr< T >::LatticeExpr ( )

Default constructor.

template<class T>

casacore::LatticeExpr< T >::LatticeExpr ( const LatticeExprNode & expr )

Constructor from an arbitrary LatticeExprNode expression object.

An exception is thrown if the expression data type cannot be converted to the template data type. The shape argument is mandatory if the expression has no shape. If the expression has a shape and if shape is given, it is checked if they are equal.

template<class T>

casacore::LatticeExpr< T >::LatticeExpr	(	const LatticeExprNode &	expr,
		const IPosition &	latticeShape
	)

template<class T>

casacore::LatticeExpr< T >::LatticeExpr ( const LatticeExpr< T > & other )

Copy constructor (reference semantics)

template<class T>

virtual casacore::LatticeExpr< T >::~LatticeExpr ( )

virtual

Destructor, does nothing.

Member Function Documentation

template<class T>

virtual MaskedLattice<T>* casacore::LatticeExpr< T >::cloneML ( ) const

virtual

Make a copy of the derived object (reference semantics).

Implements casacore::MaskedLattice< T >.

template<class T>

virtual void casacore::LatticeExpr< T >::copyDataTo ( Lattice< T > & to ) const

virtual

Copy the data from this lattice to the given lattice.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual Bool casacore::LatticeExpr< T >::doGetMaskSlice	(	Array< Bool > &	buffer,
		const Slicer &	section
	)

virtual

Do the actual get of the mask data.

The return value is always False, thus the buffer does not reference another array.

Reimplemented from casacore::MaskedLattice< T >.

template<class T>

virtual Bool casacore::LatticeExpr< T >::doGetSlice	(	Array< T > &	buffer,
		const Slicer &	section
	)

virtual

Do the actual get of the data.

The return value is always False, thus the buffer does not reference another array.

Implements casacore::Lattice< T >.

template<class T>

virtual IPosition casacore::LatticeExpr< T >::doNiceCursorShape ( uInt maxPixels ) const

virtual

Return the best cursor shape.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::LatticeExpr< T >::doPutSlice	(	const Array< T > &	sourceBuffer,
		const IPosition &	where,
		const IPosition &	stride
	)

virtual

An expression is not writable so this functions throws an exception.

Implements casacore::Lattice< T >.

template<class T>

virtual const LatticeRegion* casacore::LatticeExpr< T >::getRegionPtr ( ) const

virtual

Get the region used (always returns 0).

Implements casacore::MaskedLattice< T >.

template<class T>

virtual void casacore::LatticeExpr< T >::handleMathTo	(	Lattice< T > &	to,
		int	oper
	)		const

virtual

Handle the Math operators (+=, -=, *=, /=).

They work similarly to copyData(To). However, they are not defined for Bool types, thus specialized below.

Reimplemented from casacore::Lattice< T >.

template<>

void casacore::LatticeExpr< Bool >::handleMathTo	(	Lattice< Bool > &	,
		int
	)		const

inline

Definition at line 245 of file LatticeExpr.h.

template<class T>

virtual Bool casacore::LatticeExpr< T >::hasLock ( FileLocker::LockType ) const

virtual

Reimplemented from casacore::LatticeBase.

template<class T>

void casacore::LatticeExpr< T >::init ( const LatticeExprNode & expr )

private

Initialize the object from the expression.

template<class T>

virtual Bool casacore::LatticeExpr< T >::isMasked ( ) const

virtual

Has the object really a mask?

Reimplemented from casacore::MaskedLattice< T >.

template<class T>

virtual Bool casacore::LatticeExpr< T >::isWritable ( ) const

virtual

Returns False, as the LatticeExpr lattice is not writable.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual LELCoordinates casacore::LatticeExpr< T >::lelCoordinates ( ) const

virtual

Returns the coordinates of the lattice expression.

Reimplemented from casacore::LatticeBase.

template<class T>

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

virtual

Handle locking of the LatticeExpr which is delegated to all of its parts.

hasLock() is True if all parts of the expression return True.
It is strongly recommended to use class LatticeLocker to handle lattice locking. It also contains a more detailed explanation of the locking process.

Reimplemented from casacore::LatticeBase.

template<class T>

LatticeExpr<T>& casacore::LatticeExpr< T >::operator= ( const LatticeExpr< T > & other )

Assignment (reference semantics)

template<class T>

virtual void casacore::LatticeExpr< T >::resync ( )

virtual

Resynchronize the Lattice object with the lattice file.

This function is only useful if no read-locking is used, ie. if the table lock option is UserNoReadLocking or AutoNoReadLocking. In that cases the table system does not acquire a read-lock, thus does not synchronize itself automatically.
By default the function does not do anything at all.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual IPosition casacore::LatticeExpr< T >::shape ( ) const

virtual

Returns the shape of the Lattice including all degenerate axes (i.e.

axes with a length of one)

Implements casacore::LatticeBase.

template<class T>

virtual void casacore::LatticeExpr< T >::unlock ( )

virtual

Reimplemented from casacore::LatticeBase.