1 0 GfsSimulation GfsBox GfsGEdge {} { GfsTime { end = 50 } GfsRefine 6 GfsInit {} { U = -y V = x } GfsOutputTime { istep = 10 } stdout GfsOutputProjectionStats { istep = 10 } stdout GfsOutputPPM { step = 0.05 } rot_1.ppm { v = Vorticity } OutputSimulation { start = end } end_1.gfs } GfsBox {}