GeFEM Fem object
This object represents a finite element method on a reference element.
General constructor for Fem objects
F = Fem('interpolated_fem', MeshFem mf, MeshIm mim, [ivec blocked_dof]) Build a special Fem which is interpolated from another MeshFem.
Using this special finite element, it is possible to interpolate a given MeshFem mf on another mesh, given the integration method mim that will be used on this mesh.
Note that this finite element may be quite slow, and eats much memory.
F = Fem(string fem_name) The fem_name should contain a description of the finite element method. Please refer to the getfem++ manual (especially the description of finite element and integration methods) for a complete reference. Here is a list of some of them:
Of course, you have to ensure that the selected fem is compatible with the geometric transformation: a Pk fem has no meaning on a quadrangle.
Evaluate all basis functions of the FEM at point p.
p is supposed to be in the reference convex!
Ouput a (unique) string representation of the Fem.
This can be used to perform comparisons between two different Fem objects.
Return the dimension (dimension of the reference convex) of the Fem.
displays a short summary for a Fem object.
Return an estimation of the polynomial degree of the Fem.
This is an estimation for fem which are not polynomials.
Evaluate the gradient of all base functions of the Fem at point p.
p is supposed to be in the reference convex!
Evaluate the Hessian of all base functions of the Fem at point p.
p is supposed to be in the reference convex!.
Return the index of global dof for special fems such as interpolated fem.
Return 0 if the Fem is not equivalent.
Equivalent Fem are evaluated on the reference convex. This is the case of most classical Fem’s.
Return 0 if the Fem is not of Lagrange type.
Return 0 if the basis functions are not polynomials.
Return the number of dof for the Fem.
Some specific Fem (for example ‘interpolated_fem’) may require a convex number cv to give their result. In most of the case, you can omit this convex number.
Return the polynomial expressions of its basis functions in the reference convex.
The result is expressed as a tuple of strings. Of course this will fail on non-polynomial Fem’s.
Get the location of the dof on the reference element.
Some specific Fem may require a convex number cv to give their result (for example ‘interpolated_fem’). In most of the case, you can omit this convex number.
Return the dimension of the target space.
The target space dimension is usually 1, except for vector Fem.