Class for FAST cell list implementation. More...

Detailed Description

template<unsigned int dim, typename T, typename transform, typename base>
class CellList< dim, T, FAST, transform, base >

Class for FAST cell list implementation.

This class implement the FAST cell list, fast but memory expensive. The memory allocation is (M * N_cell_max)*sizeof(ele) + M*8

M = number of cells
N_cell_max = maximum number of elements in a cell
ele = element the structure is storing

Note: Because N_cell_max >= N/M then M * N_cell_max >= O(N)

Warning: Not not use for high asymmetric distribution

Example of a 2D Cell list 6x6 structure with padding 1 without shift, cell indicated with p are padding cell the origin of the cell or point (0,0) is marked with cell number 9

* +-----------------------+
* |p |p |p |p |p |p |p |p |
* +-----------------------+
* |p |  |  |  |  |  |  |p |
* +-----------------------+
* |p |  |  |  |  |  |  |p |
* +-----------------------+
* |p |  |  |  |  |  |  |p |
* +-----------------------+
* |p |9 |  |  |  |  |  |p |
* +-----------------------+
* |p |p |p |p |p |p |p |p |
* +-----------------------+
*

Template Parameters

dim	Dimansionality of the space
T	type of the space float, double, complex
base	Base structure that store the information

Declaration of a cell list

    //Space where is living the Cell list
    SpaceBox<dim,T> box({0.0f,0.0f,0.0f},{1.0f,1.0f,1.0f});
    // Subdivisions
    size_t div[dim] = {16,16,16};
    // Origin
    Point<dim,T> org({0.0,0.0,0.0});
    // id Cell list
    CellS cl2(box,div,org);

Usage of cell list [CellS == CellList<3,double,FAST>]

    // id Cell list
    CellS cl1(box,div,org);
    // Create a grid iterator
    grid_key_dx_iterator<dim> g_it(g_info);
    // Iterate through each element
    // Add 1 element for each cell
    // Usefull definition of points
    Point<dim,T> end = box.getP2();
    Point<dim,T> middle = end / div / 2.0;
    Point<dim,T> spacing = end / div;
    Point<dim,T> offset[dim] = {middle,middle,middle};
    // Create offset shift vectors
    for (size_t i = 0 ; i < dim ; i++)
    {
        offset[i].get(i) += (1.0 / div[i]) / 8.0;
    }
    size_t id = 0;
    while (g_it.isNext())
    {
        // Add 2 particles on each cell
        Point<dim,T> key = Point<dim,T>(g_it.get().toPoint());
        key = key * spacing + offset[0];
        cl1.add(key,id);
        ++id;
        key = Point<dim,T>(g_it.get().toPoint());
        key = key * spacing + offset[1];
        cl1.add(key,id);
        ++id;
        ++g_it;
    }

Remove one particle from each cell

    while (g_it.isNext())
    {
        // remove 1 particle on each cell
        Point<dim,T> key = Point<dim,T>(g_it.get().toPoint());
        key = key * spacing + offset[0];
        auto cell = cl1.getCell(key);
        // Remove the first particle in the cell
        cl1.remove(cell,0);
        ++g_it;
    }

Usage of the neighborhood iterator

        Point<dim,T> key = Point<dim,T>(g_it_s.get().toPoint());
        key = key * spacing + offset[0];
        auto NN = cl1.template getNNIterator<NO_CHECK>(cl1.getCell(key));
        size_t total = 0;
        while(NN.isNext())
        {
            // total
            total++;
            ++NN;
        }

Definition at line 67 of file CellListFast.hpp.

#include <CellListFast.hpp>

Inheritance diagram for CellList< dim, T, FAST, transform, base >:

Public Types
typedef T	value_type

Public Member Functions
const grid_sm< dim, void > &	getGrid ()
	Return the underlying grid information of the cell list. More...

void	Initialize (const Box< dim, T > &box, const size_t(&div)[dim], const Point< dim, T > &orig, const size_t pad=1, size_t slot=16)

void	Initialize (SpaceBox< dim, T > &box, const size_t(&div)[dim], const Point< dim, T > &orig, const size_t pad=1, size_t slot=16)

	CellList ()
	Default Constructor.

	CellList (const CellList< dim, T, FAST, transform, base > &cell)
	Copy constructor.

	CellList (CellList< dim, T, FAST, transform, base > &&cell)
	Copy constructor.

CellList< dim, T, FAST, transform, base > &	operator= (CellList< dim, T, FAST, transform, base > &&cell)
	Constructor from a temporal object. More...

CellList< dim, T, FAST, transform, base > &	operator= (const CellList< dim, T, FAST, transform, base > &cell)
	Constructor from a temporal object. More...

	CellList (Box< dim, T > &box, const size_t(&div)[dim], Matrix< dim, T > mat, Point< dim, T > &orig, const size_t pad=1, size_t slot=16)
	Cell list constructor. More...

	CellList (Box< dim, T > &box, const size_t(&div)[dim], Point< dim, T > &orig, const size_t pad=1, size_t slot=16)
	Cell list constructor. More...

	CellList (SpaceBox< dim, T > &box, const size_t(&div)[dim], Point< dim, T > &orig, const size_t pad=1, size_t slot=16)
	Cell list constructor. More...

void	addCell (size_t cell_id, typename base::value_type ele)
	Add to the cell. More...

void	add (const T(&pos)[dim], typename base::value_type ele)
	Add an element in the cell list. More...

void	add (const Point< dim, T > &pos, typename base::value_type ele)
	Add an element in the cell list. More...

void	remove (size_t cell, size_t ele)
	remove an element from the cell More...

size_t	getNelements (const size_t cell_id) const
	Return the number of element in the cell. More...

auto	get (size_t cell, size_t ele) -> decltype(cl_base.get(cell *slot+ele))
	Get an element in the cell. More...

template<unsigned int i>
auto	get (size_t cell, size_t ele) -> decltype(cl_base.get(cell *slot+ele))
	Get an element in the cell. More...

void	swap (CellList< dim, T, FAST, transform, base > &cl)
	Swap the memory. More...

CellIterator< CellList< dim, T, FAST, transform, base > >	getIterator (size_t cell)
	Get the Cell iterator. More...

template<unsigned int impl>
CellNNIterator< dim, CellList < dim, T, FAST, transform, base >, FULL, impl >	getNNIterator (size_t cell)
	Get the Neighborhood iterator. More...

template<unsigned int impl>
CellNNIterator< dim, CellList < dim, T, FAST, transform, base >, SYM, impl >	getNNIteratorSym (size_t cell)
	Get the Neighborhood iterator. More...

template<unsigned int impl>
CellNNIterator< dim, CellList < dim, T, FAST, transform, base >, CRS, impl >	getNNIteratorCross (size_t cell)
	Get the Neighborhood iterator. More...

Private Member Functions
void	realloc ()

Private Attributes
long int	NNc_full [openfpm::math::pow(3, dim)]

long int	NNc_sym [openfpm::math::pow(3, dim)/2+1]

long int	NNc_cr [openfpm::math::pow(2, dim)]

size_t	slot

openfpm::vector< size_t >	cl_n

base	cl_base

Point< dim, T >	orig

Constructor & Destructor Documentation

template<unsigned int dim, typename T , typename transform , typename base >

CellList< dim, T, FAST, transform, base >::CellList	(	Box< dim, T > &	box,
		const size_t(&)	div[dim],
		Matrix< dim, T >	mat,
		Point< dim, T > &	orig,
		const size_t	pad = `1`,
		size_t	slot = `16`
	)

inline

Cell list constructor.

Parameters

box	Domain where this cell list is living
div	grid size on each dimension
mat	Matrix transformation
orig	origin of the Cell list
pad	Cell padding
slot	maximum number of slot

Definition at line 318 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

CellList< dim, T, FAST, transform, base >::CellList	(	Box< dim, T > &	box,
		const size_t(&)	div[dim],
		Point< dim, T > &	orig,
		const size_t	pad = `1`,
		size_t	slot = `16`
	)

inline

Cell list constructor.

Parameters

box	Domain where this cell list is living
orig	origin of the Cell list
div	grid size on each dimension
pad	Cell padding
slot	maximum number of slot

Definition at line 334 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

CellList< dim, T, FAST, transform, base >::CellList	(	SpaceBox< dim, T > &	box,
		const size_t(&)	div[dim],
		Point< dim, T > &	orig,
		const size_t	pad = `1`,
		size_t	slot = `16`
	)

inline

Cell list constructor.

Parameters

box	Domain where this cell list is living
orig	origin of the Cell list
div	grid size on each dimension
pad	Cell padding
slot	maximum number of slot

Definition at line 349 of file CellListFast.hpp.

Member Function Documentation

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::add	(	const T(&)	pos[dim],
		typename base::value_type	ele
	)

inline

Add an element in the cell list.

Parameters

pos	array that contain the coordinate
ele	element to store

Definition at line 384 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::add	(	const Point< dim, T > &	pos,
		typename base::value_type	ele
	)

inline

Add an element in the cell list.

Parameters

pos	array that contain the coordinate
ele	element to store

Definition at line 401 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::addCell	(	size_t	cell_id,
		typename base::value_type	ele
	)

inline

Add to the cell.

Parameters

cell_id	Cell id where to add
ele	element to add

Definition at line 361 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

auto CellList< dim, T, FAST, transform, base >::get	(	size_t	cell,
		size_t	ele
	)		-> decltype(cl_base.get(cell * slot + ele))

inline

Get an element in the cell.

Template Parameters

i	property to get

Parameters

cell	cell id
ele	element id

Returns: The element value

Definition at line 445 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

template<unsigned int i>

auto CellList< dim, T, FAST, transform, base >::get	(	size_t	cell,
		size_t	ele
	)		-> decltype(cl_base.get(cell * slot + ele))

inline

Get an element in the cell.

Template Parameters

i	property to get

Parameters

cell	cell id
ele	element id

Returns: The element value

Definition at line 460 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

const grid_sm<dim,void>& CellList< dim, T, FAST, transform, base >::getGrid ( )

inline

Return the underlying grid information of the cell list.

Returns: the grid infos

Definition at line 134 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

CellIterator<CellList<dim,T,FAST,transform,base> > CellList< dim, T, FAST, transform, base >::getIterator ( size_t cell )

inline

Get the Cell iterator.

Parameters

cell

Returns: the iterator to the elements inside cell

Definition at line 483 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

size_t CellList< dim, T, FAST, transform, base >::getNelements ( const size_t cell_id ) const

inline

Return the number of element in the cell.

Parameters

cell_id id of the cell

Returns: number of elements in the cell

Definition at line 430 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

template<unsigned int impl>

CellNNIterator<dim,CellList<dim,T,FAST,transform,base>,FULL,impl> CellList< dim, T, FAST, transform, base >::getNNIterator ( size_t cell )

inline

Get the Neighborhood iterator.

It iterate across all the element of the selected cell and the near cells

  * * *
  * x *
  * * *

x is the selected cell
* are the near cell

Parameters

cell cell id

Definition at line 506 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

template<unsigned int impl>

CellNNIterator<dim,CellList<dim,T,FAST,transform,base>,CRS,impl> CellList< dim, T, FAST, transform, base >::getNNIteratorCross ( size_t cell )

inline

Get the Neighborhood iterator.

It iterate across all the element of the selected cell and the near cells

* *
x *

x is the selected cell
* are the near cell

Parameters

cell cell id

Definition at line 556 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

template<unsigned int impl>

CellNNIterator<dim,CellList<dim,T,FAST,transform,base>,SYM,impl> CellList< dim, T, FAST, transform, base >::getNNIteratorSym ( size_t cell )

inline

Get the Neighborhood iterator.

It iterate across all the element of the selected cell and the near cells

* * *
  x *

x is the selected cell
* are the near cell

Parameters

cell cell id

Definition at line 531 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::Initialize	(	const Box< dim, T > &	box,
		const size_t(&)	div[dim],
		const Point< dim, T > &	orig,
		const size_t	pad = `1`,
		size_t	slot = `16`
	)

inline

Initialize the cell list

Parameters

box	Domain where this cell list is living
div	grid size on each dimension
orig	origin of the Cell list
pad	padding cell
slot	maximum number of slot

Definition at line 148 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::Initialize	(	SpaceBox< dim, T > &	box,
		const size_t(&)	div[dim],
		const Point< dim, T > &	orig,
		const size_t	pad = `1`,
		size_t	slot = `16`
	)

inline

Initialize the cell list constructor

Parameters

box	Domain where this cell list is living
div	grid size on each dimension
pad	padding cell
slot	maximum number of slot

Definition at line 165 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

CellList<dim,T,FAST,transform,base>& CellList< dim, T, FAST, transform, base >::operator= ( CellList< dim, T, FAST, transform, base > && cell )

inline

Constructor from a temporal object.

Parameters

cell	Cell list structure

Definition at line 267 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

CellList<dim,T,FAST,transform,base>& CellList< dim, T, FAST, transform, base >::operator= ( const CellList< dim, T, FAST, transform, base > & cell )

inline

Constructor from a temporal object.

Parameters

cell	Cell list structure

Definition at line 292 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::remove	(	size_t	cell,
		size_t	ele
	)

inline

remove an element from the cell

Parameters

cell	cell id
ele	element id

Definition at line 418 of file CellListFast.hpp.

template<unsigned int dim, typename T , typename transform , typename base >

void CellList< dim, T, FAST, transform, base >::swap ( CellList< dim, T, FAST, transform, base > & cl )

inline

Swap the memory.

Parameters

cl	Cell list with witch you swap the memory

Definition at line 470 of file CellListFast.hpp.

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

src/NN/CellList/CellListFast.hpp

Detailed Description

template<unsigned int dim, typename T, typename transform, typename base> class CellList< dim, T, FAST, transform, base >

Declaration of a cell list

Usage of cell list [CellS == CellList<3,double,FAST>]

Remove one particle from each cell

Usage of the neighborhood iterator

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

Member Function Documentation

template<unsigned int dim, typename T, typename transform, typename base>
class CellList< dim, T, FAST, transform, base >