This stores the non-zero projection matrix elements for every 'densel' that contributes to a given bin. More...

#include "stir/recon_buildblock/ProjMatrixElemsForOneBin.h"

Public Types
typedef ProjMatrixElemsForOneBinValue	value_type
	Recommended way to call the type of the elements, instead of referring to the actual classname. More...

typedef Element_vector::iterator	iterator
	typedefs for iterator support

typedef Element_vector::const_iterator	const_iterator

typedef Element_vector::size_type	size_type

typedef Element_vector::difference_type	difference_type

typedef std::random_access_iterator_tag	iterator_category

typedef value_type &	reference

typedef const value_type &	const_reference

Public Member Functions
	ProjMatrixElemsForOneBin (const Bin &bin=Bin(), const int default_capacity=0)
	constructor More...

Succeeded	check_state () const
	check if each voxel occurs only once

const Bin &	get_bin () const
	get the bin coordinates corresponding to this row

void	set_bin (const Bin &)
	and set the bin coordinates

iterator	begin ()
	functions for allowing iterator access

const_iterator	begin () const

iterator	end ()

const_iterator	end () const

void	erase ()
	reset lor to 0 length

iterator	erase (iterator it)
	remove a single value_type

void	push_back (const value_type &)
	add a new value_type object at the end More...

void	reserve (size_type max_number)
	reserve enough space for max_number elements (but don't fill them in)

size_type	size () const
	number of non-zero elements

size_type	capacity () const
	number of allocated elements

ProjMatrixElemsForOneBin &	operator*= (const float d)
	Multiplies all values with a constant.

ProjMatrixElemsForOneBin &	operator/= (const float d)
	Divides all values with a constant.

void	sort ()
	Sort the elements on coordinates of the voxels. More...

void	merge (ProjMatrixElemsForOneBin &lor)
	merge 2nd lor into current object More...

bool	operator== (const ProjMatrixElemsForOneBin &) const
	Compare 2 lors to see if they are equal. More...

bool	operator!= (const ProjMatrixElemsForOneBin &) const
	Compare 2 lors.

float	square_sum () const
	Return sum of squares of all values. More...

void	back_project (DiscretisedDensity< 3, float > &, const Bin &) const
	back project a single bin (accumulates)

void	forward_project (Bin &, const DiscretisedDensity< 3, float > &) const
	forward project into a single bin (accumulates)

void	back_project (DiscretisedDensity< 3, float > &, const RelatedBins &) const
	back project related bins (accumulates)

void	forward_project (RelatedBins &, const DiscretisedDensity< 3, float > &) const
	forward project related bins (accumulates)

Detailed Description

This stores the non-zero projection matrix elements for every 'densel' that contributes to a given bin.

In the usual terminology, this class implements a Line (or Tube) of Response (LOR, or TOR).

Todo:: Most of the members of this class would work just as well for a (not yet existing) class ProjMatrixElemsForOneDensel. This means that we should derived both from a common base class, templated in the type of element.

Todo:: It might be useful to template this class in terms of the element-type as well. That way, we could have 'compact' elements, efficient elements, etc. However, doing this will probably only be useful if all ProjMatrixByBin classes are then templated as well, which would be a pain.

Member Typedef Documentation

◆ value_type

typedef ProjMatrixElemsForOneBinValue stir::ProjMatrixElemsForOneBin::value_type

Recommended way to call the type of the elements, instead of referring to the actual classname.

Think about this name as 'the type of the value of a ProjMatrixElemsForOneBin::iterator *'.

This typedef is also required for 'standard' iterators.

Constructor & Destructor Documentation

◆ ProjMatrixElemsForOneBin()

stir::ProjMatrixElemsForOneBin::ProjMatrixElemsForOneBin	(	const Bin &	bin = `Bin()`,
		const int	default_capacity = `0`
	)

explicit

constructor

Parameters

bin	effectively calls set_bin(bin)
default_capacity	effectively calls reserve(default_capacity)

Member Function Documentation

◆ push_back()

void stir::ProjMatrixElemsForOneBin::push_back ( const value_type & el )

inline

add a new value_type object at the end

Warning: For future compatibility, it is required (but not checked) that the elements are added such that calling sort() after the push_back() would not change the order of the elements. Otherwise, schemes for 'incremental' storing of coordinates would require too much overhead.

Referenced by merge(), stir::ProjMatrixByBinSinglePhoton::set_up(), stir::ProjMatrixByBinPinholeSPECTUB::~ProjMatrixByBinPinholeSPECTUB(), and stir::ProjMatrixByBinSPECTUB::~ProjMatrixByBinSPECTUB().

◆ sort()

void stir::ProjMatrixElemsForOneBin::sort ( )

Sort the elements on coordinates of the voxels.

Uses value_type::coordinates_less as ordering function.

References begin(), and stir::ProjMatrixElemsForOneBinValue::coordinates_less().

Referenced by check_state(), and merge().

◆ merge()

void stir::ProjMatrixElemsForOneBin::merge ( ProjMatrixElemsForOneBin & lor )

merge 2nd lor into current object

This makes sure that in the result, no duplicate coordinates occur.

Warning: This currently modifies the argument lor.

References begin(), check_state(), stir::ProjMatrixElemsForOneBinValue::coordinates_equal(), stir::ProjMatrixElemsForOneBinValue::coordinates_less(), erase(), push_back(), size(), and sort().

◆ operator==()

bool stir::ProjMatrixElemsForOneBin::operator== ( const ProjMatrixElemsForOneBin & lor ) const

Compare 2 lors to see if they are equal.

Warning: Compares element by element. Does not sort first or so.; Compares float values, so uses a tolerance. This tolerance is currently set to a fraction of the maximum value in the first lor.; this is a fairly CPU intensive operation.

References begin().

◆ square_sum()

float stir::ProjMatrixElemsForOneBin::square_sum ( ) const

Return sum of squares of all values.

Warning: This sums over all elements in the LOR, irrespective if they are inside the FOV or not

References begin(), and stir::square().

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

/home/sirfuser/devel/STIRdistrib/STIR/src/include/stir/recon_buildblock/ProjMatrixElemsForOneBin.h
/home/sirfuser/devel/STIRdistrib/STIR/src/include/stir/recon_buildblock/ProjMatrixElemsForOneBin.inl
/home/sirfuser/devel/STIRdistrib/STIR/src/recon_buildblock/ProjMatrixElemsForOneBin.cxx

Public Types

Public Member Functions