sandbox/ghigo/src/mytimestep.h
// note: u is weighted by fm
double timestep (const face vector u, double dtmax)
{
static double previous = 0.;
dtmax /= CFL;
foreach_face(reduction(min:dtmax))
if (u.x[] != 0.) {
double dt = Delta/fabs(u.x[]);
#if EMBED
assert (fm.x[]);
dt *= fm.x[];
#else
dt *= cm[];
#endif
if (dt < dtmax) dtmax = dt;
}
dtmax *= CFL;
We rest previous between successive runs.
if (t == 0.)
previous = 0.;
if (dtmax > previous)
dtmax = (previous + 0.1*dtmax)/1.1;
previous = dtmax;
return dtmax;
}