I have a question about implementing the following problem:
[tex]u_{xx} - u_{tt} = 0[/tex]
on the unit square
[tex]x,t \in [0,1][/tex]
subjected to the boundary condition
[tex]u(0,t) = 0 \ u(1,t) = 0 \ u(x,0) = 0 \ u_{t}(x,0) = \pi sin(\pi x)[/tex]

I do know how to specify the 0 boundary condition on its own. However, I am struggling with setting the starting velocity and the Dirichlet condition on the same edge. Is there a way to do that?

I guess you have one GridFunction for saving u and another GridFunction for saving the velocity u_t.
Then, at the beginning, you can set the starting velocity by

Hi Michael,
thanks for the answer and sorry for not writing back so long.
For now, I have only used the automatic utility for solving the BVP, so coming up with my own update scheme is quite a challenge. Nevertheless, I will have a look at that.