openfpm Namespace Reference

This is an N-dimensional grid or an N-dimensional array with memory_traits_lin layout. More...

Data Structures
class	vector
	Implementation of 1-D std::vector like structure. More...
class	vector_key_iterator
	Vector iterator. More...
class	vector< T, HeapMemory, grow_policy_double, STD_VECTOR >
	Implementation of 1-D std::vector like structure. More...
class	vector< T, Memory, grow_p, OPENFPM_NATIVE >
	Implementation of 1-D std::vector like structure. More...
class	grow_policy_identity
	Grow policy define how the vector should grow every time we exceed the size. More...
class	grow_policy_double
	Grow policy define how the vector should grow every time we exceed the size. More...
class	grow_policy_page
	Grow policy define how the vector should grow every time we exceed the size. More...
struct	vect_isel

Typedefs
template<typename T >
using	vector_std = vector< T, HeapMemory, openfpm::grow_policy_double, STD_VECTOR >
typedef grow_policy_double	vector_grow_policy_default
	default grow policy

Detailed Description

This is an N-dimensional grid or an N-dimensional array with memory_traits_lin layout.

It analyze the type given and it select correctly the implementation for vector.

it is basically an N-dimensional Cartesian grid

Template Parameters

dim	Dimensionality of the grid
T	type of object the grid store
S	type of memory HeapMemory CudaMemory
Mem	memory layout

Defining the grid size on each dimension

size_t sz[3] = {16,16,16};

Definition and allocation of a 3D grid on CPU memory

        grid_cpu<3, Point_test<float> > c3(sz);
        c3.setMemory();

Access a grid c3 of size sz on each direction

    typedef Point_test<float> P;

    timer t;
    t.start();

    grid_key_dx<3> kk;

    for (size_t i = 0 ; i < sz ; i++)
    {
        for (size_t j = 0 ; j < sz ; j++)
        {
            for (size_t k = 0 ; k < sz ; k++)
            {

                kk.set(i,j,k);

                c3.template get<P::x>(kk) = 1.1f;
                c3.template get<P::y>(kk) = 1.2f;
                c3.template get<P::z>(kk) = 1.3f;
                c3.template get<P::s>(kk) = 1.0f;

                c3.template get<P::v>(kk)[0] = 1.0f;
                c3.template get<P::v>(kk)[1] = 2.0f;
                c3.template get<P::v>(kk)[2] = 3.0f;

                c3.template get<P::t>(kk)[0][0] = 1.0f;
                c3.template get<P::t>(kk)[0][1] = 2.0f;
                c3.template get<P::t>(kk)[0][2] = 3.0f;
                c3.template get<P::t>(kk)[1][0] = 4.0f;
                c3.template get<P::t>(kk)[1][1] = 5.0f;
                c3.template get<P::t>(kk)[1][2] = 6.0f;
                c3.template get<P::t>(kk)[2][0] = 7.0f;
                c3.template get<P::t>(kk)[2][1] = 8.0f;
                c3.template get<P::t>(kk)[2][2] = 9.0f;

            }
        }
    }

Access an N-dimensional grid with an iterator

    typedef Point_test<float> P;

    grid_key_dx_iterator<dim> key_it = c3.getIterator();

    while (key_it.isNext())
    {
        grid_key_dx<dim> kk = key_it.get();

        c3.template get<P::x>(kk) = 1.1f;
        c3.template get<P::y>(kk) = 1.2f;
        c3.template get<P::z>(kk) = 1.3f;
        c3.template get<P::s>(kk) = 1.0f;

        c3.template get<P::v>(kk)[0] = 1.0f;
        c3.template get<P::v>(kk)[1] = 2.0f;
        c3.template get<P::v>(kk)[2] = 3.0f;

        c3.template get<P::t>(kk)[0][0] = 1.0f;
        c3.template get<P::t>(kk)[0][1] = 2.0f;
        c3.template get<P::t>(kk)[0][2] = 3.0f;
        c3.template get<P::t>(kk)[1][0] = 4.0f;
        c3.template get<P::t>(kk)[1][1] = 5.0f;
        c3.template get<P::t>(kk)[1][2] = 6.0f;
        c3.template get<P::t>(kk)[2][0] = 7.0f;
        c3.template get<P::t>(kk)[2][1] = 8.0f;
        c3.template get<P::t>(kk)[2][2] = 9.0f;

        ++key_it;

    }

Iterate only on a sub-set of the grid

    // Subdivisions
    size_t div[3] = {16,16,16};

    // grid info
    grid_sm<3,void> g_info(div);

    grid_key_dx<3> start(1,1,1);
    grid_key_dx<3> stop(14,14,14);

    // Create a grid iterator (start and stop included)
    grid_key_dx_iterator_sub<3> g_it(g_info,start,stop);

    // Iterate on all the elements
    while (g_it.isNext())
    {
        grid_key_dx<3> key = g_it.get();

        // set the grid key to zero without any reason ( to avoid warning compilations )
        key.zero();

        count++;

        ++g_it;
    }

    BOOST_REQUIRE_EQUAL(count, (size_t)14*14*14);

Get the full-object in an N-dimensional grid

    typedef Point_test<float> P;

    grid_key_dx_iterator<dim> key_it = c3.getIterator();

    while (key_it.isNext())
    {
        grid_key_dx<dim> kk = key_it.get();

        // Here we get a reference to the object, in reality we get an encapsulated object reference encapc
        auto v = c3.get_o(kk);

        // An encapsulated object can be accessed like that
        // (this will change the value in the grid)
        v.template get<P::x>() = 1.1f;
        v.template get<P::y>() = 1.2f;
        v.template get<P::z>() = 1.3f;
        v.template get<P::s>() = 1.0f;

        v.template get<P::v>()[0] = 1.0f;
        v.template get<P::v>()[1] = 2.0f;
        v.template get<P::v>()[2] = 3.0f;

        v.template get<P::t>()[0][0] = 1.0f;
        v.template get<P::t>()[0][1] = 2.0f;
        v.template get<P::t>()[0][2] = 3.0f;
        v.template get<P::t>()[1][0] = 4.0f;
        v.template get<P::t>()[1][1] = 5.0f;
        v.template get<P::t>()[1][2] = 6.0f;
        v.template get<P::t>()[2][0] = 7.0f;
        v.template get<P::t>()[2][1] = 8.0f;
        v.template get<P::t>()[2][2] = 9.0f;

        // From an encapsulated reference object you can create
        // an object
        Point_test<float> obj = c3.get_o(kk);

        // And do some operation
        obj.fill();

        // Note change obj does not change the grid

        ++key_it;

    }

Create a grid g1 and copy into another g2

    size_t sz[] = {16,16};

    typedef Box<2,float> b;

    grid_cpu<2,Box<2,float>> g1(sz);
    g1.setMemory();

    auto it = g1.getIterator();

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

        g1.template get<b::p1>(key)[0] = key.get(0);
        g1.template get<b::p2>(key)[1] = key.get(1);

        ++it;
    }

    grid_cpu<2,Box<2,float>> g2;
    g2 = g1;

Template Parameters

type	to analyze

[Example]

vect_isel<T>::value

will return 1 for std base implementation will return 2 for openfpm native implementation

Basically the openfpm native implementation require that T has some specific structure, this class check for it, if T does not have this structure it fall to the case 1