BasisFunction¶

class dolfin.cpp.fem.BasisFunction

Represention of a finite element basis function. It can be used for computation of basis function values and derivatives. Evaluation of basis functions is also possible through the use of the functions evaluate_basis and evaluate_basis_derivatives available in the FiniteElement class. The BasisFunction class relies on these functions for evaluation but also implements the ufc::function interface which allows evaluate_dof to be evaluated for a basis function (on a possibly different element).

Create basis function with given index on element on given cell

Parameters: index (std::size_t) – (std::size_t) The index of the basis function. const FiniteElement > element (std::shared_ptr<) – (FiniteElement ) The element to create basis function on. std::vector< double > & coordinate_dofs (const) – (std::vector&) The coordinate dofs of the cell
eval()

Evaluate basis function at given point

Parameters: * values (double) – (double) The values of the function at the point. double * x (const) – (double) The coordinates of the point. void
eval_derivatives()

Evaluate all order n derivatives at given point

Parameters: * values (double) – (double) The values of derivatives at the point. double * x (const) – (double) The coordinates of the point. n (std::size_t) – (std::size_t) The order of derivation. void
thisown

The membership flag

update_index()

Update the basis function index

Parameters: index (std::size_t) – (std::size_t) The index of the basis function. void