DOLFINx
0.4.1
DOLFINx C++ interface
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#include <CoordinateElement.h>
Public Member Functions | |
CoordinateElement (std::shared_ptr< const basix::FiniteElement > element) | |
Create a coordinate element from a Basix element. More... | |
CoordinateElement (mesh::CellType celltype, int degree, basix::element::lagrange_variant type=basix::element::lagrange_variant::equispaced) | |
Create a Lagrange coordinate element. More... | |
virtual | ~CoordinateElement ()=default |
Destructor. | |
mesh::CellType | cell_shape () const |
Cell shape. More... | |
int | degree () const |
The polynomial degree of the element. | |
int | dim () const |
The dimension of the geometry element space. More... | |
basix::element::lagrange_variant | variant () const |
The variant of the element. | |
std::array< std::size_t, 4 > | tabulate_shape (std::size_t nd, std::size_t num_points) const |
Shape of array to fill when calling FiniteElement::tabulate More... | |
xt::xtensor< double, 4 > | tabulate (int nd, const xt::xtensor< double, 2 > &X) const |
Evaluate basis values and derivatives at set of points. More... | |
void | tabulate (int nd, const xt::xtensor< double, 2 > &X, xt::xtensor< double, 4 > &basis) const |
Evaluate basis values and derivatives at set of points. More... | |
ElementDofLayout | create_dof_layout () const |
Compute and return the dof layout. | |
void | pull_back_nonaffine (xt::xtensor< double, 2 > &X, const xt::xtensor< double, 2 > &x, const xt::xtensor< double, 2 > &cell_geometry, double tol=1.0e-8, int maxit=10) const |
Compute reference coordinates X for physical coordinates x for a non-affine map. More... | |
void | permute_dofs (const xtl::span< std::int32_t > &dofs, std::uint32_t cell_perm) const |
Permutes a list of DOF numbers on a cell. | |
void | unpermute_dofs (const xtl::span< std::int32_t > &dofs, std::uint32_t cell_perm) const |
Reverses a DOF permutation. | |
bool | needs_dof_permutations () const |
Indicates whether the geometry DOF numbers on each cell need permuting. More... | |
bool | is_affine () const noexcept |
Check is geometry map is affine. More... | |
Static Public Member Functions | |
template<typename U , typename V , typename W > | |
static void | compute_jacobian (const U &dphi, const V &cell_geometry, W &&J) |
Compute Jacobian for a cell with given geometry using the basis functions and first order derivatives. More... | |
template<typename U , typename V > | |
static void | compute_jacobian_inverse (const U &J, V &&K) |
Compute the inverse of the Jacobian. More... | |
template<typename U > | |
static double | compute_jacobian_determinant (const U &J) |
Compute the determinant of the Jacobian. More... | |
static void | push_forward (xt::xtensor< double, 2 > &x, const xt::xtensor< double, 2 > &cell_geometry, const xt::xtensor< double, 2 > &phi) |
Compute physical coordinates x for points X in the reference configuration. More... | |
static std::array< double, 3 > | x0 (const xt::xtensor< double, 2 > &cell_geometry) |
Compute the physical coordinate of the reference point X=(0 , 0, 0) More... | |
static void | pull_back_affine (xt::xtensor< double, 2 > &X, const xt::xtensor< double, 2 > &K, const std::array< double, 3 > &x0, const xt::xtensor< double, 2 > &x) |
Compute reference coordinates X for physical coordinates x for an affine map. For the affine case, x = J X + x0 , and this function computes X = K(x -x0) where K = J^{-1} . More... | |
A CoordinateElement manages coordinate mappings for isoparametric cells.
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explicit |
Create a coordinate element from a Basix element.
[in] | element | Element from Basix |
CoordinateElement | ( | mesh::CellType | celltype, |
int | degree, | ||
basix::element::lagrange_variant | type = basix::element::lagrange_variant::equispaced |
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) |
Create a Lagrange coordinate element.
[in] | celltype | The cell shape |
[in] | degree | Polynomial degree of the map |
[in] | type | The type of Lagrange element (see Basix documentation for possible types) |
mesh::CellType cell_shape | ( | ) | const |
Cell shape.
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inlinestatic |
Compute Jacobian for a cell with given geometry using the basis functions and first order derivatives.
[in] | dphi | Derivatives of the basis functions (shape=(tdim, num geometry nodes)) |
[in] | cell_geometry | The cell nodes coordinates (shape=(num geometry nodes, gdim)) |
[out] | J | The Jacobian. It must have shape=(gdim, tdim) and must initialized to zero |
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inlinestatic |
Compute the determinant of the Jacobian.
[in] | J | Jacobian (shape=(gdim, tdim)) |
J
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inlinestatic |
Compute the inverse of the Jacobian.
[in] | J | The Jacobian (shape=(gdim, tdim)) |
[out] | K | The Jacobian (shape=(tdim, gdim)) |
int dim | ( | ) | const |
The dimension of the geometry element space.
The number of basis function is returned. E.g., for a linear triangle cell the dimension will be 3.
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inlinenoexcept |
Check is geometry map is affine.
bool needs_dof_permutations | ( | ) | const |
Indicates whether the geometry DOF numbers on each cell need permuting.
For higher order geometries (where there is more than one DOF on a subentity of the cell), this will be true.
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static |
Compute reference coordinates X for physical coordinates x for an affine map. For the affine case, x = J X + x0
, and this function computes X = K(x -x0)
where K = J^{-1}
.
[out] | X | The reference coordinates to compute (shape=(num_points, tdim)) |
[in] | K | The inverse of the geometry Jacobian (shape=(tdim, gdim)) |
[in] | x0 | The physical coordinate of reference coordinate X0=(0, 0, 0). |
[in] | x | The physical coordinates (shape=(num_points, gdim)) |
void pull_back_nonaffine | ( | xt::xtensor< double, 2 > & | X, |
const xt::xtensor< double, 2 > & | x, | ||
const xt::xtensor< double, 2 > & | cell_geometry, | ||
double | tol = 1.0e-8 , |
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int | maxit = 10 |
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) | const |
Compute reference coordinates X for physical coordinates x for a non-affine map.
[in,out] | X | The reference coordinates to compute (shape=(num_points, tdim)) |
[in] | x | The physical coordinates (shape=(num_points, gdim)) |
[in] | cell_geometry | The cell nodes coordinates (shape=(num geometry nodes, gdim)) |
[in] | tol | Tolerance for termination of Newton method. |
[in] | maxit | Maximum number of Newton iterations |
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static |
Compute physical coordinates x for points X in the reference configuration.
[in,out] | x | The physical coordinates of the reference points X |
[in] | cell_geometry | The cell node coordinates (physical) |
[in] | phi | Tabulated basis functions at reference points X |
xt::xtensor< double, 4 > tabulate | ( | int | nd, |
const xt::xtensor< double, 2 > & | X | ||
) | const |
Evaluate basis values and derivatives at set of points.
[in] | nd | The order of derivatives, up to and including, to compute. Use 0 for the basis functions only. |
[in] | X | The points at which to compute the basis functions. The shape of x is (number of points, geometric dimension). |
void tabulate | ( | int | nd, |
const xt::xtensor< double, 2 > & | X, | ||
xt::xtensor< double, 4 > & | basis | ||
) | const |
Evaluate basis values and derivatives at set of points.
[in] | nd | The order of derivatives, up to and including, to compute. Use 0 for the basis functions only. |
[in] | X | The points at which to compute the basis functions. The shape of X is (number of points, geometric dimension). |
[out] | basis | The array to fill with the basis function values. The shape can be computed using FiniteElement::tabulate_shape |
std::array< std::size_t, 4 > tabulate_shape | ( | std::size_t | nd, |
std::size_t | num_points | ||
) | const |
Shape of array to fill when calling FiniteElement::tabulate
[in] | nd | The order of derivatives, up to and including, to compute. Use 0 for the basis functions only |
[in] | num_points | Number of points at which to evaluate the basis functions |
FiniteElement::tabulate
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static |
Compute the physical coordinate of the reference point X=(0 , 0, 0)
[in] | cell_geometry | The cell nodes coordinates (shape=(num geometry nodes, gdim)) |