1 0 GfsAdvection GfsBox GfsGEdge {} {
    Refine 7
    Global {
	#define pi M_PI
    }
#    VariableStreamFunction { istep = 1 } Psi {
#	return 1.5*sin(2.*M_PI*t/5.)*sin((x + 0.5)*M_PI)*sin((y + 0.5)*M_PI)/M_PI;
#    }
    Init { istep = 1 } {
	U =   1.5*sin(2.*pi*t/5.)*sin((x + 0.5)*pi)*cos((y + 0.5)*pi)
	V = - 1.5*sin(2.*pi*t/5.)*cos((x + 0.5)*pi)*sin((y + 0.5)*pi)
    }
    VariableTracer F { cfl = 0.8 gradient = gfs_center_gradient }
    Init {} {
	F = exp(-100.*((x + 0.2)*(x + 0.2) + (y + .236338)*(y + .236338)))
    }
    Time { end = 5 dtmax = 0.1 }
    OutputScalarSum { istep = 1 } sum { v = F }
    OutputScalarStats { istep = 1 } f { v = F }
    OutputErrorNorm { start = end } stderr { v = F } { 
	s = exp(-100.*((x + 0.2)*(x + 0.2) + (y + .236338)*(y + .236338))) 
	v = E
    }
#    OutputSimulation { step = 0.1 } stdout
    OutputSimulation { start = end } end.gfs
}
GfsBox {}