fem_basis_t3_display, an Octave code which reads data defining a finite element method (FEM) linear triangular ("T3") mesh and displays the basis function associated with any node in the mesh.

The entire mesh is shown (which could be a problem for large meshes!). However, a finite element basis function is nonzero over only a relatively small number of elements. Over each one of these elements, the basis function is linear, and it is simple to represent such a shape graphically.

The best part of the presentation is that MATLAB allows the user to turn the plot or zoom in and out, which makes it much easier to understand the information that is being presented.

The triangular mesh is defined by a node file containing the coordinates of nodes, and an element file containing sets of the nodes that make up each element


fem_basis_t3_display ( 'prefix' )
where The program queries the user for a node index and then displays the basis function corresponding to that node.


The computer code and data files described and made available on this web page are distributed under the MIT license


fem_basis_t3_display is available in a MATLAB version and an Octave version.

Related Programs:


bezier_surface_display, an Octave code which displays a Bezier surface.

fem_basis_t4_display, an Octave code which displays a basis function associated with a 4-node triangle "t4" mesh.

fem_basis_t6_display, an Octave code which displays a basis function associated with a 6-node triangle "t6" mesh.

fem_io, an Octave code which reads and writes the node, element and data files that define a finite element model.

fem2d_pack, an Octave code which is useful for 2d finite element calculations.

fem2d_sample, an Octave code which evaluates a finite element function defined on an order 3 or order 6 triangulation.

polygonal_surface_display, an Octave code which reads two files defining a polygonal surface and displays it within MATLAB.

quad_surface_display, an Octave code which reads files defining a 3d quadrilateral mesh surface and displays it within MATLAB.

tet_mesh_display, an Octave code which can read in the node and tetra files defining a tet mesh and display a wireframe image.

tri_surface_display, an Octave code which reads data defining a triangular mesh of a 3d surface and displays it.

triangulation_order6, a directory which contains a description and examples of order 6 triangulations.

triangulation_order6_contour, an Octave code which can make contours of a scalar quantity defined on the nodes of an order 6 triangulation.

triangulation_plot, an Octave code which creates an eps image of a triangulation.


  1. Klaus-Juergen Bathe,
    Finite Element Procedures,
    Prentice Hall, 1996.
  2. Eric Becker, Graham Carey, John Oden,
    Finite Elements, An Introduction, Volume I,
    Prentice-Hall, 1981.
  3. Herbert Edelsbrunner,
    Geometry and Topology for Mesh Generation,
    Cambridge, 2001,
    LC: QA377.E36,
    ISBN: 0-521-79309-2.
  4. Max Gunzburger,
    Finite Element Methods for Viscous Incompressible Flows,
    A Guide to Theory, Practice, and Algorithms,
    Academic Press, 1989,
    LC: TA357.G86.
  5. Gilbert Strang, George Fix,
    An Analysis of the Finite Element Method,
    Prentice Hall, 1973,
    LC: TA335.S77.

Source code

Last revised on 17 July 2023.