1 2 GfsSimulation GfsBox GfsGEdge {} {
  Time { end = 0.5 }
  AdvectionParams { cfl = 0.75 }
  Refine (x < -0.25 || x > 0.25 || y < -0.25 || y > 0.25 ? LEVEL : LEVEL + BOX)
  Init {} {
    U = (1. - 2.*cos (2.*M_PI*x)*sin (2.*M_PI*y))
    V = (1. + 2.*sin (2.*M_PI*x)*cos (2.*M_PI*y))
  }
  ApproxProjectionParams { tolerance = 1e-6 }
  ProjectionParams { tolerance = 1e-6 }
  OutputErrorNorm { start = end } stdout { v = U } {
    s = (1. - 2.*cos (2.*M_PI*(x - t))*sin (2.*M_PI*(y - t)))
  }
}
GfsBox {}
1 1 right
1 1 top