$$
\newcommand{\uex}{{u_{\small\mbox{e}}}}
\newcommand{\half}{\frac{1}{2}}
\newcommand{\tp}{\thinspace .}
\newcommand{\Oof}[1]{\mathcal{O}(#1)}
$$
First steps for testing and debugging
- Testing very simple solutions:
\( u=\hbox{const} \) or \( u=ct + d \) do not apply here (without a force
term in the equation: \( u^{\prime\prime} + \omega^2u = f \)).
- Hand calculations: calculate \( u^1 \) and \( u^2 \) and compare with program.
