f = settings.getForce();
ParticleBoundaries particleBoundaries = new SimpleParticleBoundaries(
new DoubleBox(tstep, width, tstep, height),
settings.getParticleBoundary());
mover = new ParticleMover(
settings.getParticleSolver(),
particleBoundaries,
settings.getParticleIterator());
grid = new Grid(settings);