A 2D homogeneous Helmholtz case (u=sin(x)cos(y) with a square) with
％ two Dirichlet edges (x=1,y=1) and two Neumann edges (x=0,y=0)
％ by indirect symmetric BKM
The equation is written as a system of two first order ODEs. These are evaluated for different values of the parameter Mu. For faster integration, we choose an appropriate solver based on the value of the parameter Mu.
