Generate statistics, tile by tile, from a masked lattice NOTE this version was moved from LatticeStatistics (early Dec 2014 version) and slightly modified mostly for style issues (no significant semantic differences from that version). For a large number of statistics sets that need to be computed simultaneously, this version is more efficient than using the new stats framework, because creating large numbers of eg ClassicalStatistics objects is much less efficient than the direct manipulation of pointers to primitive types that this class does. More...

#include <StatsTiledCollapser.h>

Inheritance diagram for casacore::StatsTiledCollapser< T, U >:

Public Member Functions
	StatsTiledCollapser (const Vector< T > &pixelRange, Bool noInclude, Bool noExclude, Bool fixedMinMax)
	Constructor provides pixel selection range and whether that range is an inclusion or exclusion range. More...

virtual	~StatsTiledCollapser ()

virtual void	init (uInt nOutPixelsPerCollapse)
	Initialize process, making some checks. More...

virtual void	initAccumulator (uInt64 n1, uInt64 n3)
	Initialiaze the accumulator. More...

virtual void	process (uInt accumIndex1, uInt accumIndex3, const T inData, const Bool inMask, uInt dataIncr, uInt maskIncr, uInt nrval, const IPosition &startPos, const IPosition &shape)
	Process the data in the current chunk. More...

virtual void	endAccumulator (Array< U > &result, Array< Bool > &resultMask, const IPosition &shape)
	End the accumulation process and return the result arrays. More...

virtual Bool	canHandleNullMask () const
	Can handle null mask. More...

void	minMaxPos (IPosition &minPos, IPosition &maxPos)
	Find the location of the minimum and maximum data values in the input lattice. More...

Public Member Functions inherited from casacore::TiledCollapser< T, U >
virtual	~TiledCollapser ()
	Destructor. More...

Private Member Functions
void	_convertNPts (Double *&nptsPtr, CountedPtr< Block< Double > > npts, CountedPtr< Block< DComplex > > nptsComplex) const

void	_convertNPts (DComplex *&nptsPtr, CountedPtr< Block< Double > > npts, CountedPtr< Block< DComplex > > nptsComplex) const

Private Attributes
Vector< T >	_range

Bool	_include

Bool	_exclude

Bool	_fixedMinMax

Bool	_isReal

IPosition	_minpos

IPosition	_maxpos

CountedPtr< Block< Double > >	_npts
	Accumulators for sum, sum squared, number of points minimum, and maximum. More...

CountedPtr< Block< U > >	_sum

CountedPtr< Block< U > >	_sumSq

CountedPtr< Block< U > >	_mean

CountedPtr< Block< U > >	_variance

CountedPtr< Block< U > >	_nvariance

CountedPtr< Block< U > >	_sigma

CountedPtr< Block< T > >	_min

CountedPtr< Block< T > >	_max

CountedPtr< Block< Bool > >	_initMinMax

uInt64	_n1

uInt64	_n3

Detailed Description

template<class T, class U = T>
class casacore::StatsTiledCollapser< T, U >

Generate statistics, tile by tile, from a masked lattice NOTE this version was moved from LatticeStatistics (early Dec 2014 version) and slightly modified mostly for style issues (no significant semantic differences from that version). For a large number of statistics sets that need to be computed simultaneously, this version is more efficient than using the new stats framework, because creating large numbers of eg ClassicalStatistics objects is much less efficient than the direct manipulation of pointers to primitive types that this class does.

Intended use:

Public interface

Review Status

Date Reviewed:: yyyy/mm/dd

Prerequisite

Etymology

This class is used by LatticeStatistics to generate statistical sum from an input MaskedLattice. The input lattice is iterated through in tile-sized chunks and fed to an object of this class.

Synopsis

StatsTiledCollapser is derived from TiledCollapser which is a base class used to define methods. Objects of this base class are used by LatticeApply functions. In this particular case, we are interested in LatticeApply::tiledApply. This function iterates through a MaskedLattice and allows you to collapse one or more axes, computing some values from it, and placing those values into an output MaskedLattice. It iterates through the input lattice in optimal tile-sized chunks. LatticeStatistics uses a StatsTiledCollapser object which it gives to LatticeApply::tiledApply for digestion. After it has done its work, LatticeStatistics then accesses the output Lattice that it made.

Example

// Create collapser. Control information is passed in via the constructor
 
 StatsTiledCollapser<T> collapser(range_p, noInclude_p, noExclude_p,   
 fixedMinMax_p, blcParent_p);
 
// This is the first output axis getting  collapsed values. In LatticeStatistics
// this is the last axis of the output lattice
 
 Int newOutAxis = outLattice.ndim()-1;
 
// tiledApply does the work by passing the collapser data in chunks
// and by writing the results into the output lattice 
 
 LatticeApply<T>::tiledApply(outLattice, inLattice,
 collapser, collapseAxes,
 newOutAxis);

In this example, a collapser is made and passed to LatticeApply. Afterwards, the output Lattice is available for use. The Lattices must all be the correct shapes on input to tiledApply

Motivation

The LatticeApply classes enable the ugly details of optimal Lattice iteration to be hidden from the user.

To Do

Definition at line 113 of file StatsTiledCollapser.h.

Constructor & Destructor Documentation

template<class T , class U = T>

casacore::StatsTiledCollapser< T, U >::StatsTiledCollapser	(	const Vector< T > &	pixelRange,
		Bool	noInclude,
		Bool	noExclude,
		Bool	fixedMinMax
	)

Constructor provides pixel selection range and whether that range is an inclusion or exclusion range.

If fixedMinMax=True and an inclusion range is given, the min and max is set to that inclusion range.

template<class T , class U = T>

virtual casacore::StatsTiledCollapser< T, U >::~StatsTiledCollapser ( )

inlinevirtual

Definition at line 124 of file StatsTiledCollapser.h.

Member Function Documentation

template<class T , class U = T>

void casacore::StatsTiledCollapser< T, U >::_convertNPts	(	Double *&	nptsPtr,
		CountedPtr< Block< Double > >	npts,
		CountedPtr< Block< DComplex > >	nptsComplex
	)		const

private

template<class T , class U = T>

void casacore::StatsTiledCollapser< T, U >::_convertNPts	(	DComplex *&	nptsPtr,
		CountedPtr< Block< Double > >	npts,
		CountedPtr< Block< DComplex > >	nptsComplex
	)		const

private

template<class T , class U = T>

virtual Bool casacore::StatsTiledCollapser< T, U >::canHandleNullMask ( ) const

inlinevirtual

Can handle null mask.

Reimplemented from casacore::TiledCollapser< T, U >.

Definition at line 147 of file StatsTiledCollapser.h.

References casacore::True.

template<class T , class U = T>

virtual void casacore::StatsTiledCollapser< T, U >::endAccumulator	(	Array< U > &	result,
		Array< Bool > &	resultMask,
		const IPosition &	shape
	)

virtual

End the accumulation process and return the result arrays.

Implements casacore::TiledCollapser< T, U >.

template<class T , class U = T>

virtual void casacore::StatsTiledCollapser< T, U >::init ( uInt nOutPixelsPerCollapse )

virtual

Initialize process, making some checks.

Implements casacore::TiledCollapser< T, U >.

template<class T , class U = T>

virtual void casacore::StatsTiledCollapser< T, U >::initAccumulator	(	uInt64	n1,
		uInt64	n3
	)

virtual

Initialiaze the accumulator.

Implements casacore::TiledCollapser< T, U >.

template<class T , class U = T>

void casacore::StatsTiledCollapser< T, U >::minMaxPos	(	IPosition &	minPos,
		IPosition &	maxPos
	)

Find the location of the minimum and maximum data values in the input lattice.

template<class T , class U = T>

virtual void casacore::StatsTiledCollapser< T, U >::process	(	uInt	accumIndex1,
		uInt	accumIndex3,
		const T *	inData,
		const Bool *	inMask,
		uInt	dataIncr,
		uInt	maskIncr,
		uInt	nrval,
		const IPosition &	startPos,
		const IPosition &	shape
	)