D< d, Field, Sys_eqs, impl > Class Template Reference

Derivative second order on h (spacing) More...

Detailed Description

template<unsigned int d, typename Field, typename Sys_eqs, unsigned int impl = CENTRAL>
class D< d, Field, Sys_eqs, impl >

Derivative second order on h (spacing)

Template Parameters

d	on which dimension derive
Field	which field derive
impl	which implementation

Definition at line 28 of file Derivative.hpp.

#include <Derivative.hpp>

Static Private Member Functions
static void	value (const grid_key_dx< Sys_eqs::dims > &pos, const grid_sm< Sys_eqs::dims, void > &gs, std::unordered_map< long int, typename Sys_eqs::stype > &cols, typename Sys_eqs::stype coeff)
	Calculate which colums of the Matrix are non zero. More...
static grid_key_dx< Sys_eqs::dims >	position (grid_key_dx< Sys_eqs::dims > &pos, const grid_sm< Sys_eqs::dims, void > &gs, const comb< Sys_eqs::dims >(&s_pos)[Sys_eqs::nvar])
	Calculate the position where the derivative is calculated. More...

Member Function Documentation

template<unsigned int d, typename Field, typename Sys_eqs, unsigned int impl = CENTRAL>

static grid_key_dx<Sys_eqs::dims> D< d, Field, Sys_eqs, impl >::position ( grid_key_dx< Sys_eqs::dims > &  pos, const grid_sm< Sys_eqs::dims, void > &  gs, const comb< Sys_eqs::dims >(&)  s_pos[Sys_eqs::nvar]  )

inlinestaticprivate

Calculate the position where the derivative is calculated.

In case of non staggered case this function just return a null grid_key, in case of staggered, it calculate how the operator shift the calculation in the cell

Parameters

pos	position where we are calculating the derivative
gs	Grid info
s_pos	staggered position of the properties

Returns

where (in which cell) the derivative is calculated

Definition at line 59 of file Derivative.hpp.

template<unsigned int d, typename Field, typename Sys_eqs, unsigned int impl = CENTRAL>

static void D< d, Field, Sys_eqs, impl >::value ( const grid_key_dx< Sys_eqs::dims > &  pos, const grid_sm< Sys_eqs::dims, void > &  gs, std::unordered_map< long int, typename Sys_eqs::stype > &  cols, typename Sys_eqs::stype  coeff  )

inlinestaticprivate

Calculate which colums of the Matrix are non zero.

Parameters

pos	position where the derivative is calculated
gs	Grid info
cols	non-zero colums calculated by the function
coeff	coefficent (constant in front of the derivative)

Example

    // grid size
    size_t sz[2]={16,16};

    // grid_dist_testing
    grid_dist_testing<2> g_map(sz);

    // grid_sm
    grid_sm<2,void> ginfo(sz);

    // spacing
    float spacing[2] = {0.5,0.3};

    // Create several keys
    grid_dist_key_dx<2> key11(0,grid_key_dx<2>(1,1));
    grid_dist_key_dx<2> key00(0,grid_key_dx<2>(0,0));
    grid_dist_key_dx<2> key22(0,grid_key_dx<2>(2,2));
    grid_dist_key_dx<2> key1515(0,grid_key_dx<2>(15,15));

    // filled colums
    std::unordered_map<long int,float> cols_x;
    std::unordered_map<long int,float> cols_y;

    D<x,Field<V,sys_nn>,sys_nn>::value(g_map,key11,ginfo,spacing,cols_x,1);
    D<y,Field<V,sys_nn>,sys_nn>::value(g_map,key11,ginfo,spacing,cols_y,1);

    BOOST_REQUIRE_EQUAL(cols_x.size(),2ul);
    BOOST_REQUIRE_EQUAL(cols_y.size(),2ul);

    BOOST_REQUIRE_EQUAL(cols_x[17+1],1/spacing[0]/2.0);
    BOOST_REQUIRE_EQUAL(cols_x[17-1],-1/spacing[0]/2.0);

    BOOST_REQUIRE_EQUAL(cols_y[17+16],1/spacing[1]/2.0);
    BOOST_REQUIRE_EQUAL(cols_y[17-16],-1/spacing[1]/2.0);

Definition at line 42 of file Derivative.hpp.

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

• openfpm_numerics/src/FiniteDifference/Derivative.hpp