On Tue, May 20, 2008 at 09:43:54PM +0200, Evan Lezar wrote: > Hi there > > As an initial attempt, I am trying to use fenics to compute the resonant > modes of a rectangular waveguide - and as such I need to solve an > eigenvalue problem of the form [A]x = lambda[B]x where x represents a > vector of coefficients of the basis functions used to calculate the > entries of the stiffness ([A]) and mass ([B]) matrices. > > It is easy to assemble the matrices, and I have solved the eigenvalue > problem using eigs() ... but now I have the calculated coefficients and > I would like to plot the weighted sum of the basis functions (the finite > element solution). > > Any help on the matter would be much appreciated. > > Thanks > Evan
Are you doing this in Python or C++? If x is the vector, then you can do Function u(mesh, x, a); where a is the form in C++. In Python, you need to do Function u(element, mesh, x); where element is the FiniteElement you have used for the trial space. To plot the solution, just do plot(u); -- Anders _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
