The 1+1-dimensional wave equation reads ∂2u∂x2=∂2u∂t2, with u=u(x,t) and we have assumed that we operate with dimensionless variables. Possible boundary and initial conditions with L=1 are uxx=uttx∈(0,1),t>0u(x,0)=g(x)x∈(0,1)u(0,t)=u(1,t)=0t>0∂u/∂t|t=0=0x∈(0,1).