Table 6 Periodic case: Computational errors in the energy norm and experimental orders of convergence for ${\mathit{P}}^{\mathbf{1}}$ approximation on a consequence of meshes at time instances t ( $\mathit{\tau }\mathbf{=}{\mathbf{10}}^{\mathbf{-}\mathbf{3}}$ )

h

${\mathbf{err}}_{\mathit{h}}^{\mathbf{1}}$

EOC

${\mathbf{err}}_{\mathit{h}}^{\mathbf{1}}$

EOC

${\mathbf{err}}_{\mathit{h}}^{\mathbf{1}}$

EOC

${\mathbf{err}}_{\mathit{h}}^{\mathbf{1}}$

EOC