FEM1D_LAGRANGE
1D Finite Element Code Using Lagrange Basis Polynomials

FEM1D_LAGRANGE, a MATLAB library which sets up the matrices and vectors associated with the finite element method (FEM) solution of a boundary value problem (BVP) -u''+u=f(x), using Lagrange basis polynomials.

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

FEM1D_LAGRANGE is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Programs:

FEM1D, a MATLAB program which applies the finite element method (FEM) to a 1D linear two point boundary value problem (BVP).

fem1d_lagrange_test

FEM1D_SPECTRAL_NUMERIC, a MATLAB program which applies the spectral finite element method (FEM) to solve the two point boundary value problem (BVP_ u'' = - pi^2 sin(x) over [-1,+1] with zero boundary conditions, using as basis elements the functions x^n*(x-1)*(x+1), and carrying out the integration numerically, using MATLAB's quad() function, by Miro Stoyanov.

LAGRANGE_INTERP_1D, a MATLAB library which defines and evaluates the Lagrange polynomial p(x) which interpolates a set of data, so that p(x(i)) = y(i).

Source Code:

• fem1d_lagrange_stiffness.m computes the stiffness matrix, mass matrix, and right hand side for a finite element problem that uses Lagrange basis polynomials.
• lagrange_derivative.m, evaluates the derivative of Lagrange basis polynomials.
• lagrange_value.m, evaluates the Lagrange basis polynomials.
• legendre_set.m, sets the points and weights of a Legendre quadrature rule.
• r8vec_print.m, prints an R8VEC.
• timestamp.m, prints the current YMDHMS date as a timestamp;