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2.4.7 Lax-Friedrichs scheme

Figure 14: Stencil and example for Lax-Friedrichs scheme.
\includegraphics[width=8.0cm]{images/pde1d_stencil_mp.ps} \includegraphics[width=8.0cm]{images/pde1d_solve_linadv_spikes_lax-friedrichs_i200n500dt04.ps}
Figure 14: Lax-Friedrichs scheme with flux
\begin{displaymath}
\textstyle
f_{i+\frac{1}{2}}^n = \frac{1}{2} \left[ f \! \...
...lta t}
\left[ \rho_{i+1}^n -
\rho_{i}^n
\right]
\enspace .
\end{displaymath} (115)
The smearing is so strong that not even the number of the initial spikes is conserved. And there are some non-decaying small-scale wiggles left.

Note: odd-even decoupling.