CartDecomposition.hpp

/*
 * CartDecomposition.hpp
 *
 *  Created on: Oct 07, 2015
 *      Author: Pietro Incardona, Antonio Leo
 */

#ifndef CARTDECOMPOSITION_HPP
#define CARTDECOMPOSITION_HPP

#include "config.h"
#include <cmath>
#include "VCluster.hpp"
#include "Graph/CartesianGraphFactory.hpp"
#include "Decomposition.hpp"
#include "Vector/map_vector.hpp"
#include <vector>
#include <initializer_list>
#include "SubdomainGraphNodes.hpp"
#include "dec_optimizer.hpp"
#include "Space/Shape/Box.hpp"
#include "Space/Shape/Point.hpp"
#include "NN/CellList/CellDecomposer.hpp"
#include <unordered_map>
#include "NN/CellList/CellList.hpp"
#include "Space/Ghost.hpp"
#include "common.hpp"
#include "ie_loc_ghost.hpp"
#include "ie_ghost.hpp"
#include "nn_processor.hpp"
#include "GraphMLWriter/GraphMLWriter.hpp"
#include "Distribution/ParMetisDistribution.hpp"
#include "Distribution/DistParMetisDistribution.hpp"
#include "Distribution/MetisDistribution.hpp"
#include "DLB/DLB.hpp"
#include "util/se_util.hpp"
#include "util/mathutil.hpp"
#include "CartDecomposition_ext.hpp"

#define CARTDEC_ERROR 2000lu

/**
 * \brief This class decompose a space into sub-sub-domains and distribute them across processors
 *
 * \tparam dim is the dimensionality of the physical domain we are going to decompose.
 * \tparam T type of the space we decompose, Real, Integer, Complex ...
 * \tparam Memory Memory factory used to allocate memory
 * \tparam Distribution type of distribution, can be ParMetisDistribution or MetisDistribution
 *
 * Given an N-dimensional space, this class decompose the space into a Cartesian grid of small
 * sub-sub-domain. To each sub-sub-domain is assigned an id that identify at which processor is
 * assigned (in general the union of all the sub-sub-domain assigned to a processor is
 * simply connected space), a second step merge several sub-sub-domain with same id into bigger region
 *  sub-domain. Each sub-domain has an extended space called ghost part
 *
 * Assuming that VCluster.getProcessUnitID(), equivalent to the MPI processor rank, return the processor local
 * processor id, we define
 *
 * * local processor: processor rank
 * * local sub-domain: sub-domain given to the local processor
 * * external ghost box: (or ghost box) are the boxes that compose the ghost space of the processor, or the
 *   boxes produced expanding every local sub-domain by the ghost extension and intersecting with the sub-domain
 *   of the other processors
 * * Near processors are the processors adjacent to the local processor, where with adjacent we mean all the processor
 *   that has a non-zero intersection with the ghost part of the local processor, or all the processors that
 *   produce non-zero external boxes with the local processor, or all the processor that should communicate
 *   in case of ghost data synchronization
 * * internal ghost box: is the part of ghost of the near processor that intersect the space of the
 *       processor, or the boxes produced expanding the sub-domain of the near processors with the local sub-domain
 * * Near processor sub-domain: is a sub-domain that live in the a near (or contiguous) processor
 * * Near processor list: the list of all the near processor of the local processor (each processor has a list
 *                        of the near processor)
 * * Local ghosts internal or external are all the ghosts that does not involve inter-processor communications
 *
 * \see calculateGhostBoxes() for a visualization of internal and external ghost boxes
 *
 * ### Create a Cartesian decomposition object on a Box space, distribute, calculate internal and external ghost boxes
 *
 * \snippet CartDecomposition_unit_test.hpp Create CartDecomposition
 *
 */

template<unsigned int dim, typename T, typename Memory, typename Distribution>
class CartDecomposition: public ie_loc_ghost<dim, T>, public nn_prcs<dim, T>, public ie_ghost<dim, T>
{

public:

	//! Type of the domain we are going to decompose
	typedef T domain_type;

	//! It simplify to access the SpaceBox element
	typedef SpaceBox<dim, T> Box;

	//! This class is base of itself
	typedef CartDecomposition<dim,T,Memory,Distribution> base_type;

	//! This class admit a class defined on an extended domain
	typedef CartDecomposition_ext<dim,T,Memory,Distribution> extended_type;

protected:

	//! This is the key type to access  data_s, for example in the case of vector
	//! acc_key is size_t
	typedef typename openfpm::vector<SpaceBox<dim, T>,
			Memory,
			typename memory_traits_lin<SpaceBox<dim, T>>::type,
			memory_traits_lin,
			openfpm::vector_grow_policy_default,
			openfpm::vect_isel<SpaceBox<dim, T>>::value>::access_key acc_key;

	//! the set of all local sub-domain as vector
	openfpm::vector<SpaceBox<dim, T>> sub_domains;

	//! for each sub-domain, contain the list of the neighborhood processors
	openfpm::vector<openfpm::vector<long unsigned int> > box_nn_processor;

	//! Structure that contain for each sub-sub-domain box the processor id
	//! exist for efficient global communication
	openfpm::vector<size_t> fine_s;

	//! Structure that store the cartesian grid information
	grid_sm<dim, void> gr;

	//! Structure that decompose your structure into cell without creating them
	//! useful to convert positions to CellId or sub-domain id in this case
	CellDecomposer_sm<dim, T, shift<dim,T>> cd;

	//! rectangular domain to decompose
	::Box<dim,T> domain;

	//! Box Spacing
	T spacing[dim];

	//! Runtime virtual cluster machine
	Vcluster & v_cl;

	//! Create distribution
	Distribution dist;

	//! Smallest subdivision on each direction
	::Box<dim,T> ss_box;

	//! Processor bounding box
	::Box<dim,T> bbox;

	//! reference counter of the object in case is shared between object
	long int ref_cnt;

	//! ghost info
	Ghost<dim,T> ghost;

	//! Boundary condition info
	size_t bc[dim];

	/*! \brief It convert the box from the domain decomposition into sub-domain
	 *
	 * The decomposition box from the domain-decomposition contain the box in integer
	 * coordinates
	 *
	 * \param loc_box local box
	 *
	 * \return the corresponding sib-domain
	 *
	 */
	SpaceBox<dim,T> convertDecBoxIntoSubDomain(const SpaceBox<dim,size_t> & loc_box)
	{
		// A point with all coordinate to one
		size_t one[dim];
		for (size_t i = 0 ; i < dim ; i++)	{one[i] = 1;}

		SpaceBox<dim, size_t> sub_dc = loc_box;
		SpaceBox<dim, size_t> sub_dce = sub_dc;
		sub_dce.expand(one);
		SpaceBox<dim, T> sub_d(sub_dce);
		sub_d.mul(spacing);
		sub_d += domain.getP1();

		// we add the

		// Fixing sub-domains to cover all the domain

		// Fixing sub_d
		// if (loc_box) is at the boundary we have to ensure that the box span the full
		// domain (avoiding rounding off error)
		for (size_t i = 0; i < dim; i++)
		{
			if (sub_dc.getHigh(i) == cd.getGrid().size(i) - 1)
				sub_d.setHigh(i, domain.getHigh(i));

			if (sub_dc.getLow(i) == 0)
				sub_d.setLow(i,domain.getLow(i));
		}

		return sub_d;
	}

protected:



public:

	/*! \brief Constructor, it decompose and distribute the sub-domains across the processors
	 *
	 * \param v_cl Virtual cluster, used internally for communications
	 * \param bc boundary conditions
	 *
	 */
	void createSubdomains(Vcluster & v_cl, const size_t (& bc)[dim])
	{
#ifdef SE_CLASS1
		if (&v_cl == NULL)
		{
			std::cerr << __FILE__ << ":" << __LINE__ << " error VCluster instance is null, check that you ever initialized it \n";
			ACTION_ON_ERROR()
		}
#endif

		int p_id = v_cl.getProcessUnitID();

		// Calculate the total number of box and and the spacing
		// on each direction
		// Get the box containing the domain
		SpaceBox<dim, T> bs = domain.getBox();

		for (unsigned int i = 0; i < dim; i++)
		{
			// Calculate the spacing
			spacing[i] = (bs.getHigh(i) - bs.getLow(i)) / gr.size(i);
		}

		// fill the structure that store the processor id for each sub-domain
		fine_s.resize(gr.size());

		// Optimize the decomposition creating bigger spaces
		// And reducing Ghost over-stress
		dec_optimizer<dim, Graph_CSR<nm_v, nm_e>> d_o(dist.getGraph(), gr.getSize());

		// set of Boxes produced by the decomposition optimizer
		openfpm::vector<::Box<dim, size_t>> loc_box;

		// Ghost
		Ghost<dim,long int> ghe;

		// Set the ghost
		for (size_t i = 0 ; i < dim ; i++)
		{
			ghe.setLow(i,static_cast<long int>(ghost.getLow(i)/spacing[i]) - 1);
			ghe.setHigh(i,static_cast<long int>(ghost.getHigh(i)/spacing[i]) + 1);
		}

		// optimize the decomposition
		d_o.template optimize<nm_v::sub_id, nm_v::proc_id>(dist.getGraph(), p_id, loc_box, box_nn_processor,ghe,bc);

		// reset ss_box
		ss_box = domain;
		ss_box -= ss_box.getP1();

		// Initialize ss_box and bbox
		if (loc_box.size() >= 0)
			bbox = convertDecBoxIntoSubDomain(loc_box.get(0));

		// convert into sub-domain
		for (size_t s = 0; s < loc_box.size(); s++)
		{
			SpaceBox<dim,T> sub_d = convertDecBoxIntoSubDomain(loc_box.get(s));

			// add the sub-domain
			sub_domains.add(sub_d);

			// Calculate the bound box
			bbox.enclose(sub_d);

			// Create the smallest box contained in all sub-domain
			ss_box.contained(sub_d);
		}

		nn_prcs<dim,T>::create(box_nn_processor, sub_domains);
		nn_prcs<dim,T>::refine_ss_box(ss_box);
		nn_prcs<dim,T>::applyBC(domain,ghost,bc);

		// fill fine_s structure
		// fine_s structure contain the processor id for each sub-sub-domain
		// with sub-sub-domain we mean the sub-domain decomposition before
		// running dec_optimizer (before merging sub-domains)
		auto it = dist.getGraph().getVertexIterator();

		while (it.isNext())
		{
			size_t key = it.get();

			// fill with the fine decomposition
			fine_s.get(key) = dist.getGraph().template vertex_p<nm_v::proc_id>(key);

			++it;
		}

		Initialize_geo_cell_lists();
	}

	/*! \brief Initialize geo_cell lists
	 *
	 *
	 *
	 */
	void Initialize_geo_cell_lists()
	{
		// Get the smallest sub-division on each direction
		::Box<dim, T> unit = getSmallestSubdivision();
		// Get the processor bounding Box
		::Box<dim,T> bound = getProcessorBounds();
		// Not necessary, but I prefer
		bound.enlarge(ghost);

		// calculate the sub-divisions
		size_t div[dim];
		for (size_t i = 0; i < dim; i++)
			div[i] = (size_t) ((bound.getHigh(i) - bound.getLow(i)) / unit.getHigh(i));

		// Initialize the geo_cell structure
		ie_ghost<dim,T>::Initialize_geo_cell(bound,div);

		// Initialize shift vectors
		ie_ghost<dim,T>::generateShiftVectors(domain);
	}

	/*! \brief Calculate communication and migration costs
	 *
	 * \param ts how many timesteps have passed since last calculation, used to approximate the cost
	 */
	void computeCommunicationAndMigrationCosts(size_t ts)
	{
		float migration = 0;

		SpaceBox<dim, T> cellBox = cd.getCellBox();
		float b_s = static_cast<float>(cellBox.getHigh(0));
		float gh_s = static_cast<float>(ghost.getHigh(0));

		// compute the gh_area for 2 dim case
		float gh_v = (gh_s * b_s);

		// multiply for sub-sub-domain side for each domain
		for (size_t i = 2; i < dim; i++)
			gh_v *= b_s;

		size_t norm = (size_t) (1.0 / gh_v);

		migration = pow(b_s, dim);

		size_t prev = 0;

		for (size_t i = 0; i < dist.getNSubSubDomains(); i++)
		{
			dist.setMigrationCost(i, norm * migration * dist.getSubSubDomainComputationCost(i));

			for (size_t s = 0; s < dist.getNSubSubDomainNeighbors(i); s++)
			{
				dist.setCommunicationCost(i, s, 1 * dist.getSubSubDomainComputationCost(i) * ts);
			}
			prev += dist.getNSubSubDomainNeighbors(i);
		}
	}

	/*! \brief Create the subspaces that decompose your domain
	 *
	 */
	void CreateSubspaces()
	{
		// Create a grid where each point is a space
		grid_sm<dim, void> g(div);

		// create a grid_key_dx iterator
		grid_key_dx_iterator<dim> gk_it(g);

		// Divide the space into subspaces
		while (gk_it.isNext())
		{
			//! iterate through all subspaces
			grid_key_dx<dim> key = gk_it.get();

			//! Create a new subspace
			SpaceBox<dim, T> tmp;

			//! fill with the Margin of the box
			for (int i = 0; i < dim; i++)
			{
				tmp.setHigh(i, (key.get(i) + 1) * spacing[i]);
				tmp.setLow(i, key.get(i) * spacing[i]);
			}

			//! add the space box
			sub_domains.add(tmp);

			// add the iterator
			++gk_it;
		}
	}


	/*! It calculate the internal ghost boxes
	 *
	 * Example: Processor 10 calculate
	 * B8_0 B9_0 B9_1 and B5_0
	 *
	 *
	 *
	 \verbatim

	+----------------------------------------------------+
	|                                                    |
	|                 Processor 8                        |
	|                 Sub+domain 0                       +-----------------------------------+
	|                                                    |                                   |
	|                                                    |                                   |
	++--------------+---+---------------------------+----+        Processor 9                |
	 |              |   |     B8_0                  |    |        Subdomain 0                |
	 |              +------------------------------------+                                   |
	 |              |   |                           |    |                                   |
	 |              |   |                           |B9_0|                                   |
	 |              | B |    Local processor        |    |                                   |
	 | Processor 5  | 5 |    Subdomain 0            |    |                                   |
	 | Subdomain 0  | _ |                           +----------------------------------------+
	 |              | 0 |                           |    |                                   |
	 |              |   |                           |    |                                   |
	 |              |   |                           |    |        Processor 9                |
	 |              |   |                           |B9_1|        Subdomain 1                |
	 |              |   |                           |    |                                   |
	 |              |   |                           |    |                                   |
	 |              |   |                           |    |                                   |
	 +--------------+---+---------------------------+----+                                   |
														 |                                   |
														 +-----------------------------------+


 \endverbatim

       and also
       G8_0 G9_0 G9_1 G5_0 (External ghost boxes)

\verbatim

		  +----------------------------------------------------+
		  |                 Processor 8                        |
		  |                 Subdomain 0                        +-----------------------------------+
		  |                                                    |                                   |
		  |           +---------------------------------------------+                              |
		  |           |         G8_0                           |    |                              |
	+-----+---------------+------------------------------------+    |   Processor 9                |
	|                 |   |                                    |    |   Subdomain 0                |
	|                 |   |                                    |G9_0|                              |
	|                 |   |                                    |    |                              |
	|                 |   |                                    |    |                              |
	|                 |   |        Local processor             |    |                              |
	|  Processor 5    |   |        Sub+domain 0                |    |                              |
	|  Subdomain 0    |   |                                    +-----------------------------------+
	|                 |   |                                    |    |                              |
	|                 | G |                                    |    |                              |
	|                 | 5 |                                    |    |   Processor 9                |
	|                 | | |                                    |    |   Subdomain 1                |
	|                 | 0 |                                    |G9_1|                              |
	|                 |   |                                    |    |                              |
	|                 |   |                                    |    |                              |
	+---------------------+------------------------------------+    |                              |
					  |                                        |    |                              |
					  +----------------------------------------+----+------------------------------+

	 \endverbatim

	 *
	 *
	 *
	 * \param ghost margins for each dimensions (p1 negative part) (p2 positive part)
	 *
	 *
	 \verbatim

	 	 	 	 	 ^ p2[1]
	 	 	 	 	 |
	 	 	 	 	 |
	 	 	 	+----+----+
	 	 	 	|         |
	 	 	 	|         |
	 p1[0]<-----+         +----> p2[0]
	 	 	 	|         |
	 	 	 	|         |
	 	 	 	+----+----+
	 	 	 	 	 |
	 	 	 	 	 v  p1[1]

	 \endverbatim

	 *
	 *
	 */
	void calculateGhostBoxes()
	{
		// Intersect all the local sub-domains with the sub-domains of the contiguous processors

		// create the internal structures that store ghost information
		ie_ghost<dim, T>::create_box_nn_processor_ext(v_cl, ghost, sub_domains, box_nn_processor, *this);
		ie_ghost<dim, T>::create_box_nn_processor_int(v_cl, ghost, sub_domains, box_nn_processor, *this);

		ie_loc_ghost<dim,T>::create(sub_domains,domain,ghost,bc);
	}

public:

	//! Space dimensions
	static constexpr int dims = dim;

	//! Space type
	typedef T stype;

	//! Increment the reference counter
	void incRef()
	{ref_cnt++;}

	//! Decrement the reference counter
	void decRef()
	{ref_cnt--;}

	//! Return the reference counter
	long int ref()
	{
		return ref_cnt;
	}

	/*! \brief Cartesian decomposition constructor
	 *
	 * \param v_cl Virtual cluster, used internally to handle or pipeline communication
	 *
	 */
	CartDecomposition(Vcluster & v_cl) :
			nn_prcs<dim, T>(v_cl), v_cl(v_cl), dist(v_cl),ref_cnt(0)
	{
		// Reset the box to zero
		bbox.zero();
	}

	/*! \brief Cartesian decomposition copy constructor
	 *
     * \param cart object to copy
	 *
	 */
	CartDecomposition(const CartDecomposition<dim,T,Memory> & cart)
	:nn_prcs<dim,T>(cart.v_cl),v_cl(cart.v_cl),dist(v_cl),ref_cnt(0)
	{
		this->operator=(cart);
	}

	/*! \brief Cartesian decomposition copy constructor
	 *
     * \param cart object to copy
	 *
	 */
	CartDecomposition(CartDecomposition<dim,T,Memory> && cart)
	:nn_prcs<dim,T>(cart.v_cl),v_cl(cart.v_cl),dist(v_cl),ref_cnt(0)
	{
		this->operator=(cart);
	}

	//! Cartesian decomposition destructor
	~CartDecomposition()
	{
	}

	/*! \brief class to select the returned id by ghost_processorID
	 *
	 */
	class box_id
	{
	public:
		/*! \brief Return the box id
		 *
		 * \param p structure containing the id informations
		 * \param b_id box_id
		 *
		 * \return box id
		 *
		 */
		inline static size_t id(p_box<dim, T> & p, size_t b_id)
		{
			return b_id;
		}
	};

	/*! \brief class to select the returned id by ghost_processorID
	 *
	 */
	class processor_id
	{
	public:
		/*! \brief Return the processor id
		 *
		 * \param p structure containing the id informations
		 * \param b_id box_id
		 *
		 * \return processor id
		 *
		 */
		inline static size_t id(p_box<dim, T> & p, size_t b_id)
		{
			return p.proc;
		}
	};

	/*! \brief class to select the returned id by ghost_processorID
	 *
	 */
	class lc_processor_id
	{
	public:
		/*! \brief Return the near processor id
		 *
		 * \param p structure containing the id informations
		 * \param b_id box_id
		 *
		 * \return local processor id
		 *
		 */
		inline static size_t id(p_box<dim, T> & p, size_t b_id)
		{
			return p.lc_proc;
		}
	};

	/*! \brief class to select the returned id by ghost_processorID
	 *
	 */
	class shift_id
	{
	public:
		/*! \brief Return the shift id
		 *
		 * \param p structure containing the id informations
		 * \param b_id box_id
		 *
		 * \return shift_id id
		 *
		 */
		inline static size_t id(p_box<dim,T> & p, size_t b_id)
		{
			return p.shift_id;
		}
	};

	/*! \brief Apply boundary condition to the point
	 *
	 * If the particle go out to the right, bring back the particle on the left
	 * in case of periodic, nothing in case of non periodic
	 *
	 * \param pt Point to apply the boundary condition. (it's coordinated are changed according the
	 *        the explanation before)
	 *
	 */
	void applyPointBC(float (& pt)[dim]) const
	{
		for (size_t i = 0 ; i < dim ; i++)
		{
			if (bc[i] == PERIODIC)
				pt[i] = openfpm::math::periodic_l(pt[i],domain.getHigh(i),domain.getLow(i));
		}
	}

	/*! \brief Apply boundary condition to the point
	 *
	 * If the particle go out to the right, bring back the particle on the left
	 * in case of periodic, nothing in case of non periodic
	 *
	 * \param pt Point to apply the boundary conditions.(it's coordinated are changed according the
	 *        the explanation before)
	 *
	 */
	void applyPointBC(Point<dim,T> & pt) const
	{
		for (size_t i = 0 ; i < dim ; i++)
		{
			if (bc[i] == PERIODIC)
				pt.get(i) = openfpm::math::periodic_l(pt.get(i),domain.getHigh(i),domain.getLow(i));
		}
	}

	/*! \brief Apply boundary condition to the point
	 *
	 * If the particle go out to the right, bring back the particle on the left
	 * in case of periodic, nothing in case of non periodic
	 *
	 * \param pt encapsulated point object (it's coordinated are changed according the
	 *        the explanation before)
	 *
	 */
	template<typename Mem> void applyPointBC(encapc<1,Point<dim,T>,Mem> && pt) const
	{
		for (size_t i = 0 ; i < dim ; i++)
		{
			if (bc[i] == PERIODIC)
				pt.template get<0>()[i] = openfpm::math::periodic_l(pt.template get<0>()[i],domain.getHigh(i),domain.getLow(i));
		}
	}

	/*! \brief It create another object that contain the same decomposition information but with different ghost boxes
	 *
	 * \param g ghost
	 *
	 * \return a duplicated decomposition with different ghost boxes
	 *
	 */
	CartDecomposition<dim,T,Memory> duplicate(const Ghost<dim,T> & g) const
	{
		CartDecomposition<dim,T,Memory> cart(v_cl);

		cart.box_nn_processor = box_nn_processor;
		cart.sub_domains = sub_domains;
		cart.fine_s = fine_s;

		cart.gr = gr;
		cart.cd = cd;
		cart.domain = domain;
		std::copy(spacing,spacing+3,cart.spacing);

		cart.bbox = bbox;
		cart.ss_box = ss_box;
		cart.ghost = g;

		cart.dist = dist;

		for (size_t i = 0 ; i < dim ; i++)
			cart.bc[i] = bc[i];

		(static_cast<nn_prcs<dim,T> &>(cart)).create(box_nn_processor, sub_domains);
		(static_cast<nn_prcs<dim,T> &>(cart)).applyBC(domain,ghost,bc);

		cart.Initialize_geo_cell_lists();
		cart.calculateGhostBoxes();

		return cart;
	}

	/*! \brief It create another object that contain the same information and act in the same way
	 *
	 * \return a duplicated CartDecomposition object
	 *
	 */
	CartDecomposition<dim,T,Memory> duplicate() const
	{
		CartDecomposition<dim,T,Memory> cart(v_cl);

		(static_cast<ie_loc_ghost<dim,T>*>(&cart))->operator=(static_cast<ie_loc_ghost<dim,T>>(*this));
		(static_cast<nn_prcs<dim,T>*>(&cart))->operator=(static_cast<nn_prcs<dim,T>>(*this));
		(static_cast<ie_ghost<dim,T>*>(&cart))->operator=(static_cast<ie_ghost<dim,T>>(*this));

		cart.sub_domains = sub_domains;
		cart.box_nn_processor = box_nn_processor;
		cart.fine_s = fine_s;
		cart.gr = gr;
		cart.cd = cd;
		cart.domain = domain;
		std::copy(spacing,spacing+3,cart.spacing);

		cart.ghost = ghost;

		cart.bbox = bbox;
		cart.ss_box = ss_box;

		for (size_t i = 0 ; i < dim ; i++)
			cart.bc[i] = this->bc[i];

		return cart;
	}

	/*! \brief Copy the element
	 *
	 * \param cart element to copy
	 *
	 * \return itself
	 *
	 */
	CartDecomposition<dim,T,Memory> & operator=(const CartDecomposition & cart)
	{
		static_cast<ie_loc_ghost<dim,T>*>(this)->operator=(static_cast<ie_loc_ghost<dim,T>>(cart));
		static_cast<nn_prcs<dim,T>*>(this)->operator=(static_cast<nn_prcs<dim,T>>(cart));
		static_cast<ie_ghost<dim,T>*>(this)->operator=(static_cast<ie_ghost<dim,T>>(cart));

		sub_domains = cart.sub_domains;
		box_nn_processor = cart.box_nn_processor;
		fine_s = cart.fine_s;
		gr = cart.gr;
		cd = cart.cd;
		domain = cart.domain;
		std::copy(cart.spacing,cart.spacing+3,spacing);

		ghost = cart.ghost;

		bbox = cart.bbox;
		ss_box = cart.ss_box;

		for (size_t i = 0 ; i < dim ; i++)
			bc[i] = cart.bc[i];

		return *this;
	}

	/*! \brief Copy the element, move semantic
	 *
	 * \param cart element to copy
	 *
	 * \return itself
	 *
	 */
	CartDecomposition<dim,T,Memory> & operator=(CartDecomposition && cart)
	{
		static_cast<ie_loc_ghost<dim,T>*>(this)->operator=(static_cast<ie_loc_ghost<dim,T>>(cart));
		static_cast<nn_prcs<dim,T>*>(this)->operator=(static_cast<nn_prcs<dim,T>>(cart));
		static_cast<ie_ghost<dim,T>*>(this)->operator=(static_cast<ie_ghost<dim,T>>(cart));

		sub_domains.swap(cart.sub_domains);
		box_nn_processor.swap(cart.box_nn_processor);
		fine_s.swap(cart.fine_s);
		gr = cart.gr;
		cd = cart.cd;
		domain = cart.domain;
		std::copy(cart.spacing,cart.spacing+3,spacing);

		ghost = cart.ghost;

		bbox = cart.bbox;
		ss_box = cart.ss_box;

		for (size_t i = 0 ; i < dim ; i++)
			bc[i] = cart.bc[i];

		return *this;

		return *this;
	}

	/*! \brief The default grid size
	 *
	 *  The default grid is always an isotropic grid that adapt with the number of processors,
	 *  it define in how many cell it will be divided the space for a particular required minimum
	 *  number of sub-domain
	 *
	 * \param n_sub number of subdomains per processors
	 *
	 * \return grid dimension (it is one number because on the other dimensions is the same)
	 *
	 */
	static size_t getDefaultGrid(size_t n_sub)
	{
		// Calculate the number of sub-sub-domain on
		// each dimension
		return openfpm::math::round_big_2(pow(n_sub, 1.0 / dim));
	}

	/*! \brief Given a point return in which processor the particle should go
	 *
	 * \param p point
	 *
	 * \return processorID
	 *
	 */
	template<typename Mem, typename ofb> size_t inline processorID(encapc<1, Point<dim,T>, Mem> p)
	{
		return fine_s.get(cd.template getCell<ofb>(p));
	}

	/*! \brief Given a point return in which processor the particle should go
	 *
	 * \param p point
	 *
	 * \return processorID
	 *
	 */
	size_t inline processorID(const Point<dim,T> &p) const
	{
		return fine_s.get(cd.getCell(p));
	}

	/*! \brief Given a point return in which processor the particle should go
	 *
	 * \param p point
	 *
	 * \return processorID
	 *
	 */
	size_t inline processorID(const T (&p)[dim]) const
	{
		return fine_s.get(cd.getCell(p));
	}

	/*! \brief Given a point return in which processor the point/particle should go
	 *
	 * Boundary conditions are considered
	 *
	 * \param p point
	 *
	 * \return processorID
	 *
	 */
	template<typename Mem> size_t inline processorIDBC(encapc<1, Point<dim,T>, Mem> p)
	{
		Point<dim,T> pt = p;
		applyPointBC(pt);

		return fine_s.get(cd.getCell(pt));
	}

	/*! \brief Given a point return in which processor the particle should go
	 *
	 * Boundary conditions are considered
	 *
	 * \param p point
	 *
	 * \return processorID
	 *
	 */
	template<typename ofb> size_t inline processorIDBC(const Point<dim,T> &p) const
	{
		Point<dim,T> pt = p;
		applyPointBC(pt);

		return fine_s.get(cd.getCell(p));
	}

	/*! \brief Given a point return in which processor the particle should go
	 *
	 * Boundary consition are considered
	 *
	 * \param p point position
	 *
	 * \return processorID
	 *
	 */
	template<typename ofb> size_t inline processorIDBC(const T (&p)[dim]) const
	{
		Point<dim,T> pt = p;
		applyPointBC(pt);

		return fine_s.get(cd.getCell(p));
	}

	/*! \brief Get the smallest subdivision of the domain on each direction
	 *
	 * \return a box p1 is set to zero
	 *
	 */
	const ::Box<dim,T> & getSmallestSubdivision()
	{
		return ss_box;
	}

	/*! \brief Get the periodicity on i dimension
	 *
	 * \param i dimension
	 *
	 * \return the periodicity in direction i
	 *
	 */
	inline size_t periodicity(size_t i)
	{
		return bc[i];
	}

	/*! \brief Get the periodicity
	 *
	 *
	 * \return the periodicity
	 *
	 */
	inline const size_t (& periodicity() const) [dim]
	{
		return bc;
	}

	/*! \brief Set the parameter of the decomposition
	 *
	 * \param div_ storing into how many sub-sub-domains to decompose on each dimension
	 * \param domain_ domain to decompose
	 * \param bc boundary conditions
	 * \param ghost Ghost size
	 *
	 */
	void setParameters(const size_t (& div_)[dim], ::Box<dim,T> domain_, const size_t (& bc)[dim] ,const Ghost<dim,T> & ghost)
	{
		// set the boundary conditions
		for (size_t i = 0 ; i < dim ; i++)
			this->bc[i] = bc[i];

		// set the ghost
		this->ghost = ghost;

		// Set the decomposition parameters
		gr.setDimensions(div_);
		domain = domain_;
		cd.setDimensions(domain, div_, 0);

		// init distribution
		dist.createCartGraph(gr, domain);