# Glossary¶

- Convex¶
See

**element**- Cubature method¶
A cubature method on an

**element**consists in a set of nodes (generally called gauss points) and corresponding loads which define a approximated integration method. In*GetFEM*it is defined on the**reference elements**.- Degree of freedom¶
The degrees of freedom for a finite element method is the coefficients which multiply the shape functions in order to describe a (scalar or vector) field. Generally, they are the unknowns of the problem in general.

- Element¶
An element is a small piece of a domain with a special shape (a segment, a triangle, a quadrilateron, an tetrahedron, a hexahedron or a prism) for dimensions less or equal to three. A mesh is the union of non intersecting elements.

- Finite element method (fem)¶
A finite element method is defined on a real element. It consist on a certain number of degrees of freedom linked to the corresponding shape functions and a manner to glue the degrees of freedom from a element to a neighbour element.

- Integration method¶
See

**cubature method**.- Quadrature method¶
See

**cubature method**.- Mesh¶
The mesh is composed of

**elements**. in*GetFEM*, these elements are often called**convexes**. A mesh can be composed of elements of different dimensions (triangles, segments, quadrilaters, tetrahedra, hexahedra …).- Mesh_Fem¶
The mesh_fem object is a mesh with a

**finite element method**defined on each**element**. This represent a finite element space on which a unknown or a data on the considered domain will be described.- Mesh_Im¶
The mesh_im object is a mesh with a

**cubature method**defined on each**element**. It is used in assembly procedures.- Reference element¶
A reference element or a convex of reference is a special

**element**on which the elementary computations (integrals) are performed. For instance, the reference segment in*GetFEM*is the segment [0,1]. The reference triangle is the triangle (0,0), (0,1), (1,0). etc.