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Wave equation

\frac{\partial \dot s}{\partial t} =
c^2 ( \frac{\partial^...
...}{\partial {x_2}^2} +
\frac{\partial^2 s}{\partial {x_3}^2} )

\frac{\partial s}{\partial t} = \dot s

The primary unknowns are the wave_scalar $s$ and its first time derivative wave_fscalar $\dots $ ( as TOCHNOG only solves first order in time equations, the first time derivative of $s$ also becomes primary unknown in order to turn this second order in time equation into a set of first order in time equations). Further notation: $x$ space coordinate, $t$ time and $c$ speed of sound.

tochnog 2001-09-02