Ejemplo n.º 1
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def test_field_derivative():
    f = Frame()
    f.addfield("Y", 1.)
    f.addintegrationvariable("x", 0.)

    def diff(f, x, Y):
        return -Y

    f.Y.differentiator = diff
    with pytest.raises(RuntimeError):
        f.Y.derivative()
    f.integrator = Integrator(f.x)
    f.integrator._var = None
    with pytest.raises(RuntimeError):
        f.Y.derivative()
    f.integrator = Integrator(f.x)
    assert np.all(f.Y.derivative() == -f.Y)
    f.addfield("Y", [1., 0])
    assert np.all(f.Y.derivative() == 0.)

    def jac(f, x):
        return [[2., 0], [0., 2.]]

    f.Y.jacobinator = jac
    assert np.all(f.Y.derivative() == [2., 0.])
Ejemplo n.º 2
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def test_frame_run():
    f = Frame()
    f.verbosity = 0
    f.addintegrationvariable("x", 0.)
    with pytest.raises(RuntimeError):
        f.run()
    f.integrator = Integrator(f.x)
    f.integrator._var = None
    with pytest.raises(RuntimeError):
        f.run()
    f.integrator = Integrator(f.x)
    with pytest.raises(RuntimeError):
        f.run()
    f.x = 3.
    f.x.snapshots = [1., 2.]
    with pytest.raises(RuntimeError):
        f.run()

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x = 1.5
    f.run()
    assert np.all(f.x == 2.)
Ejemplo n.º 3
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    def initialize(self):
        '''Function initializes the simulation frame.

        Function sets all fields that are None with a standard value.
        If the grids are not set, it will call ``Simulation.makegrids()`` first.'''
        if not isinstance(self.grid.Nm, Field) or not isinstance(self.grid.Nr, Field):
            self.makegrids()

        # INTEGRATION VARIABLE
        if self.t is None:
            self.t = IntVar(self, 0., description="Time [s]")
            self.t.cfl = 0.1
            self.t.updater = std.sim.dt
            self.t.snapshots = np.logspace(3., 5., num=21, base=10.) * c.year

        # STELLAR QUANTITIES
        self._initializestar()

        # GRID QUANTITIES
        self._initializegrid()

        # GAS QUANTITIES
        self._initializegas()

        # DUST QUANTITIES
        self._initializedust()

        # INTEGRATOR
        if self.integrator is None:
            instructions = [
                Instruction(std.dust.impl_1_direct,
                            self.dust.Sigma,
                            controller={"rhs": self.dust._rhs
                                        },
                            description="Dust: implicit 1st-order direct solver"
                            ),
                Instruction(std.gas.impl_1_direct,
                            self.gas.Sigma,
                            controller={"rhs": self.gas._rhs
                                        },
                            description="Gas: implicit 1st-order direct solver"
                            ),
            ]
            self.integrator = Integrator(
                self.t, description="Default integrator")
            self.integrator.instructions = instructions
            self.integrator.preparator = std.sim.prepare_implicit_dust
            self.integrator.finalizer = std.sim.finalize_implicit_dust

        # WRITER
        if self.writer is None:
            self.writer = hdf5writer()

        # Updating the entire Simulation object including integrator finalization
        self.integrator._finalize()
        self.update()
Ejemplo n.º 4
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def test_expl_5_cash_karp_adptv():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested

    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(0.1)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.expl_5_cash_karp_adptv,
                    f.Y,
                    controller={"eps": 1.e-3})
    ]

    f.run()
    assert np.allclose(f.Y, 4.57114092616805e-05)
Ejemplo n.º 5
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def test_namespacewriter_simple():
    f = Frame()
    f.addfield("Y", 1.)
    f.addgroup("A")
    f.A.addfield("B", 0.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 1.

    f.x.updater = dx
    f.x.snapshots = [1.]
    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_1_euler, f.Y)]
    f.writer = writers.namespacewriter()
    f.writer.dumping = True
    f.run()
    Y = f.writer.read.sequence("Y")
    assert np.all(Y == [1., 0.])
    x = f.writer.read.sequence("x")
    assert np.all(x == [0., 1.])
    data = f.writer.read.all()
    assert np.all(data.Y == [1., 0.])
    assert np.all(data.x == [0., 1.])
    f.writer.reset()
Ejemplo n.º 6
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def test_expl_2_heun_euler_adaptive():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested

    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(0.1)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.expl_2_heun_euler_adptv,
                    f.Y,
                    controller={"eps": 1.e-3})
    ]

    f.run()
    assert np.allclose(f.Y, 4.553150014598088e-05)
Ejemplo n.º 7
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def test_impl_1_euler_gmres_fail():
    f = Frame()
    f.addfield("Y", 1.)

    def jac(f, x):
        return np.array([-1.])

    f.Y.jacobinator = jac
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.impl_1_euler_gmres,
                    f.Y,
                    controller={
                        "gmres_opt": {
                            "atol": 0.,
                            "tol": 1.e-18,
                            "maxiter": 1
                        }
                    })
    ]

    with pytest.raises(StopIteration):
        f.run()
Ejemplo n.º 8
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def test_expl_3_gottlieb_shu_adptv():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested

    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(0.1)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.expl_3_gottlieb_shu_adptv,
                    f.Y,
                    controller={"eps": 1.e-4})
    ]

    f.run()
    assert np.allclose(f.Y, 4.5390485375346277e-05)
Ejemplo n.º 9
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def test_expl_5_dormand_prince_adptv():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested

    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(0.1)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.expl_5_dormand_prince_adptv,
                    f.Y,
                    controller={"eps": 1.e-2})
    ]

    f.run()
    assert np.allclose(f.Y, 1.8016162079480785e-06)
Ejemplo n.º 10
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def test_field_jacobian():
    f = Frame()
    f.addfield("Y", 1.)
    f.addintegrationvariable("x", 0.)

    def jac(f, x):
        if x == None:
            return 0.
        else:
            return x

    f.Y.jacobinator = jac
    with pytest.raises(RuntimeError):
        f.Y.jacobian()
    f.integrator = Integrator(f.x)
    f.integrator._var = None
    with pytest.raises(RuntimeError):
        f.Y.jacobian()
    f.integrator = Integrator(f.x)
    assert f.Y.jacobian() == 0.
    assert f.Y.jacobian(x=1.) == 1.
Ejemplo n.º 11
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def test_simple_read_files():
    f = Frame()
    f.addgroup("A")
    f.A.addfield("B", [0., 0.])
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 1.

    f.x.updater = dx
    f.x.snapshots = [1.]
    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_1_euler, f.Y)]
    f.writer = writers.hdf5writer()
    f.run()
    x = f.writer.read.sequence("x")
    assert np.all(x == [0., 1.])
    Y = f.writer.read.sequence("Y")
    assert np.all(Y == [1., 0.])
    B = f.writer.read.sequence("A.B")
    assert np.all(B == [0., 0.])
    with pytest.raises(TypeError):
        f.writer.read.sequence(1)
    data = f.writer.read.all()
    assert np.all(data.x == [0., 1.])
    assert np.all(data.Y == [1., 0.])
    assert np.all(data.A.B == [0., 0.])
    data0000 = f.writer.read.output(0)
    assert np.all(data0000.x == 0.)
    assert np.all(data0000.Y == 1.)
    assert np.all(data0000.A.B == 0.)
    with pytest.raises(RuntimeError):
        f.writer.read.output(2)
    shutil.rmtree(f.writer.datadir)
    with pytest.raises(RuntimeError):
        f.writer.datadir = "temp"
        f.writer.read.all()
    with pytest.raises(RuntimeError):
        f.writer.read.sequence("x")
    f.writer.datadir = "data"
Ejemplo n.º 12
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def test_simple():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y
    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 1.
    f.x.updater = dx
    f.x.snapshots = [1.]
    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_1_euler, f.Y)]
    f.run()
    assert f.Y == 0.
    assert f.x.prevstepsize == 1.
Ejemplo n.º 13
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def test_group_repr_str():
    f = Frame()
    assert isinstance(repr(f), str)
    assert isinstance(str(f), str)
    f.addintegrationvariable("x", 0)
    f.addfield("Y", 1.)
    f.addfield("abcdefghijklm", 0.)
    f.addgroup("A")
    f.addgroup("BCDEFGHIJKLMN")
    f.C = None
    f.abcdef1234567 = None
    f.A.addfield("k", 0.)
    assert isinstance(repr(f), str)
    assert isinstance(str(f), str)
    assert isinstance(repr(f.A), str)
    assert isinstance(str(f.A), str)
    f.integrator = Integrator(f.x)
    f.writer = writers.namespacewriter()
    assert isinstance(repr(f), str)
    assert isinstance(str(f), str)
Ejemplo n.º 14
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def test_expl_4_runge_kutta():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_4_runge_kutta, f.Y)]

    f.run()
    assert np.allclose(f.Y, 4.540034101629485e-05)
Ejemplo n.º 15
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def test_expl_1_euler():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_1_euler, f.Y)]

    f.run()
    assert np.allclose(f.Y, 2.656139888758694e-05)
Ejemplo n.º 16
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def test_adaptive_update():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y
    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested
    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(100.)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_5_cash_karp_adptv, f.Y),
                                 Instruction(schemes.update, f.Y)]

    f.run()
    assert f.Y == 5.34990702474703e-3
Ejemplo n.º 17
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def test_expl_2_heun():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y

    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.expl_2_heun, f.Y)]

    f.run()
    assert np.allclose(f.Y, 4.6222977814657625e-05)
Ejemplo n.º 18
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def test_impl_1_euler_gmres():
    f = Frame()
    f.addfield("Y", 1.)

    def jac(f, x):
        return np.array([-1.])

    f.Y.jacobinator = jac
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(schemes.impl_1_euler_gmres, f.Y)]

    f.run()
    assert np.allclose(f.Y, 7.256571590148018e-05)
Ejemplo n.º 19
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def test_adaptive_fail():
    f = Frame()
    f.addfield("Y", 1.)

    def dYdx(f, x, Y):
        return -Y
    f.Y.differentiator = dYdx
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return f.x.suggested
    f.x.updater = dx
    f.x.snapshots = [10.]
    f.x.suggest(100.)

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [Instruction(
        schemes.expl_5_cash_karp_adptv, f.Y)]
    f.integrator.maxit = 1

    with pytest.raises(StopIteration):
        f.run()
Ejemplo n.º 20
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def test_impl_2_midpoint_direct():
    f = Frame()
    f.addfield("Y", 1.)

    def jac(f, x):
        return np.array([-1.])

    f.Y.jacobinator = jac
    f.addintegrationvariable("x", 0.)

    def dx(f):
        return 0.1

    f.x.updater = dx
    f.x.snapshots = [10.]

    f.integrator = Integrator(f.x)
    f.integrator.instructions = [
        Instruction(schemes.impl_2_midpoint_direct, f.Y)
    ]

    f.run()
    assert np.allclose(f.Y, 4.5022605238147066e-05)
Ejemplo n.º 21
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def test_integrator_attributes():
    f = Frame()
    iv = IntVar(f, 0)
    i = Integrator(iv)
    with pytest.raises(TypeError):
        i.description = 1
    with pytest.raises(TypeError):
        i.maxit = "_"
    with pytest.raises(ValueError):
        i.maxit = 0
    with pytest.raises(TypeError):
        i.var = 1
    hb = Heartbeat()
    i.preparator = hb
    assert i.preparator == hb
    i.finalizer = hb
    assert i.finalizer == hb
    i.failop = hb
    assert i.failop == hb
    with pytest.raises(TypeError):
        i.instructions = 1
    with pytest.raises(TypeError):
        i.instructions = [1]
Ejemplo n.º 22
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def test_integrator_repr_str():
    f = Frame()
    iv = IntVar(f, 0)
    i = Integrator(iv)
    assert isinstance(repr(i), str)
    assert isinstance(str(i), str)
Ejemplo n.º 23
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class Simulation(Frame):
    """The main simulation class for running dust coagulation simulations.

    `dustpy.Simulation`` is a child of ``simframe.Frame``.

    For setting simple initial conditions use ``Simulation.ini``,
    For making the simulation grids use ``Simulation.makegrids()``,
    For initialization use ``Simulation.initialize()``,
    For running simulations use ``Simulation.run()``.

    Please have a look at the documentation of ``simframe`` for further details."""

    __name__ = "DustPy"

    def __init__(self, **kwargs):
        """Main simulation class."""

        super().__init__(**kwargs)

        # Namespace with parameters to set the initial conditions
        self._ini = SimpleNamespace(**{"dust": SimpleNamespace(**{"aIniMax": 0.0001,
                                                                  "allowDriftingParticles": False,
                                                                  "erosionMassRatio": 10.,
                                                                  "d2gRatio": 1.e-2,
                                                                  "distExp": -3.5,
                                                                  "excavatedMass": 1.,
                                                                  "fragmentDistribution": -11/6,
                                                                  "rhoMonomer": 1.67,
                                                                  "vfrag": 100.
                                                                  }
                                                               ),
                                       "gas": SimpleNamespace(**{"alpha": 1.e-3,
                                                                 "gamma": 1.4,
                                                                 "Mdisk": 0.05*c.M_sun,
                                                                 "mu": 2.3*c.m_p,
                                                                 "SigmaExp": -1.,
                                                                 "SigmaRc": 60.*c.au
                                                                 }
                                                              ),
                                       "grid": SimpleNamespace(**{"Nmbpd": 7,
                                                                  "mmin": 1.e-12,
                                                                  "mmax": 1.e5,
                                                                  "Nr": 100,
                                                                  "rmin": 1.*c.au,
                                                                  "rmax": 1000.*c.au
                                                                  }
                                                               ),
                                       "star": SimpleNamespace(**{"M": 1.*c.M_sun,
                                                                  "R": 2.*c.R_sun,
                                                                  "T": 5772.,
                                                                  }
                                                               )
                                       }
                                    )

        # Initializing everything with None to get the basic frame

        # Dust quantities
        self.dust = Group(self, description="Dust quantities")
        self.dust.a = None
        self.dust.backreaction = Group(
            self, description="Backreaction coefficients")
        self.dust.backreaction.A = None
        self.dust.backreaction.B = None
        self.dust.backreaction.updater = ["A", "B"]
        self.dust.boundary = Group(self, description="Boundary conditions")
        self.dust.boundary.inner = None
        self.dust.boundary.outer = None
        self.dust.coagulation = Group(
            self, description="Coagulation quantities")
        self.dust.coagulation.stick = None
        self.dust.coagulation.stick_ind = None
        self.dust.coagulation.A = None
        self.dust.coagulation.eps = None
        self.dust.coagulation.lf_ind = None
        self.dust.coagulation.rm_ind = None
        self.dust.coagulation.phi = None
        self.dust.D = None
        self.dust.delta = Group(self, description="Mixing parameters")
        self.dust.delta.rad = None
        self.dust.delta.turb = None
        self.dust.delta.vert = None
        self.dust.delta.updater = ["rad", "turb", "vert"]
        self.dust.eps = None
        self.dust.Fi = Group(self, description="Fluxes")
        self.dust.Fi.adv = None
        self.dust.Fi.diff = None
        self.dust.Fi.tot = None
        self.dust.Fi.updater = ["adv", "diff", "tot"]
        self.dust.fill = None
        self.dust.H = None
        self.dust.kernel = None
        self.dust.rho = None
        self.dust.rhos = None
        self.dust.p = Group(self, description="Probabilities")
        self.dust.p.frag = None
        self.dust.p.stick = None
        self.dust.p.updater = ["frag", "stick"]
        self.dust.S = Group(self, description="Sources")
        self.dust.S.coag = None
        self.dust.S.ext = None
        self.dust.S.hyd = None
        self.dust.S.tot = None
        self.dust.S.updater = ["ext", "tot"]
        self.dust.Sigma = None
        self.dust.SigmaFloor = None
        self.dust.St = None
        self.dust.v = Group(self, description="Velocities")
        self.dust.v.frag = None
        self.dust.v.rel = Group(self, description="Relative velocities")
        self.dust.v.rel.azi = None
        self.dust.v.rel.brown = None
        self.dust.v.rel.rad = None
        self.dust.v.rel.tot = None
        self.dust.v.rel.turb = None
        self.dust.v.rel.vert = None
        self.dust.v.rel.updater = [
            "azi", "brown", "rad", "turb", "vert", "tot"]
        self.dust.v.driftmax = None
        self.dust.v.rad = None
        self.dust.v.updater = ["frag", "driftmax", "rel"]
        self.dust.updater = ["delta", "rhos", "fill", "a", "St", "H",
                             "rho", "backreaction", "v", "D", "eps", "kernel", "p", "S"]

        # Gas quantities
        self.gas = Group(self, description="Gas quantities")
        self.gas.alpha = None
        self.gas.boundary = Group(self, description="Boundary conditions")
        self.gas.boundary.inner = None
        self.gas.boundary.outer = None
        self.gas.cs = None
        self.gas.eta = None
        self.gas.Fi = None
        self.gas.gamma = None
        self.gas.Hp = None
        self.gas.mfp = None
        self.gas.mu = None
        self.gas.n = None
        self.gas.nu = None
        self.gas.P = None
        self.gas.rho = None
        self.gas.S = Group(self, description="Source terms")
        self.gas.S.ext = None
        self.gas.S.hyd = None
        self.gas.S.tot = None
        self.gas.S.updater = ["ext", "tot"]
        self.gas.Sigma = None
        self.gas.SigmaFloor = None
        self.gas.T = None
        self.gas.v = Group(self, description="Velocities")
        self.gas.v.rad = None
        self.gas.v.visc = None
        self.gas.v.updater = ["visc", "rad"]
        self.gas.updater = ["gamma", "mu", "T", "alpha", "cs", "Hp", "nu",
                            "rho", "n", "mfp", "P", "eta", "S"]

        # Grid quantities
        self.grid = Group(self, description="Grid quantities")
        self.grid.Nr = None
        self.grid.r = None
        self.grid.ri = None
        self.grid.A = None
        self.grid.Nm = None
        self.grid.m = None
        self.grid.OmegaK = None
        self.grid.updater = ["OmegaK"]

        # Stellar quantities
        self.star = Group(self, description="Stellar quantities")
        self.star.L = None
        self.star.M = None
        self.star.R = None
        self.star.T = None
        self.star.updater = ["M", "R", "T", "L"]

        # Updater of frame object
        self.updater = ["star", "grid", "gas", "dust"]

        self.t = None

    def run(self):
        """This functions runs the simulation."""
        # Print welcome message
        if self.verbosity > 0:
            msg = ""
            msg += "\nDustPy v{}".format(self.__version__)
            msg += "\n"
            msg += "\nDocumentation: {}".format(
                "https://stammler.github.io/dustpy/")
            msg += "\nPyPI:          {}".format(
                "https://pypi.org/project/dustpy/")
            msg += "\nGitHub:        {}".format(
                "https://github.com/stammler/dustpy/")
            msg += "\n"
            msg += colorize("\nPlease cite Stammler & Birnstiel (2022).", "blue")
            print(msg)
        # Check for mass conserbation
        self.checkmassconservation()
        # Actually run the simulation
        super().run()

    @property
    def ini(self):
        '''Parameter set for setting the initial conditions.'''
        return self._ini

    def makegrids(self):
        '''Function creates radial and mass grid.

        Notes
        -----
        The grids are set up with the parameters given in ``Simulation.ini``.
        If you want to have a custom radial grid you have to set the array of grid cell interfaces ``Simulation.grid.ri``,
        before calling ``Simulation.makegrids()``.
        You cannot have a customized mass grid, because the coagulation alorithm strictly needs a logarithmic grid. Always
        set your mass grid parameters with ``Simulation.ini``.'''
        self._makemassgrid()
        self._makeradialgrid()

    def _makemassgrid(self):
        '''Function sets the radial mass grid. If ``Simulation.grid.rint`` is not given it uses the parameters set in
        ``Simulation.ini``.'''
        logmmin = np.log10(self.ini.grid.mmin)
        logmmax = np.log10(self.ini.grid.mmax)
        decades = np.ceil(logmmax - logmmin)
        Nm = int(decades * self.ini.grid.Nmbpd) + 1
        m = np.logspace(np.log10(self.ini.grid.mmin), np.log10(
            self.ini.grid.mmax), num=Nm, base=10.)
        self.grid.Nm = Field(
            self, Nm, description="# of mass bins", constant=True)
        self.grid.m = Field(
            self, m, description="Mass grid [g]", constant=True)

    def _makeradialgrid(self):
        '''Function sets the mass grid using the parameters set in ``Simulation.ini``.'''
        if self.grid.ri is None:
            ri = np.logspace(np.log10(self.ini.grid.rmin), np.log10(
                self.ini.grid.rmax), num=self.ini.grid.Nr+1, base=10.)
            Nr = self.ini.grid.Nr
        else:
            ri = self.grid.ri
            Nr = ri.shape[0] - 1
        r = 0.5*(ri[:-1] + ri[1:])
        A = np.pi*(ri[1:]**2 - ri[:-1]**2)
        self.grid.Nr = Field(
            self, Nr, description="# of radial grid cells", constant=True)
        self.grid.r = Field(
            self, r, description="Radial grid cell centers [cm]", constant=True)
        self.grid.ri = Field(
            self, ri, description="Radial grid cell interfaces [cm]", constant=True)
        self.grid.A = Field(
            self, A, description="Radial grid annulus area [cm²]", constant=True)

    def checkmassconservation(self):
        """Function checks for mass conservation and prints the maximum relative mass error."""

        # Check if required fields are present
        if self.dust.coagulation.stick is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.stick' is not set.")
        if self.dust.coagulation.stick_ind is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.stick_ind' is not set.")
        if self.dust.coagulation.A is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.A' is not set.")
        if self.dust.coagulation.eps is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.eps' is not set.")
        if self.dust.coagulation.lf_ind is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.lf_ind' is not set.")
        if self.dust.coagulation.rm_ind is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.rm_ind' is not set.")
        if self.dust.coagulation.phi is None:
            raise RuntimeError(
                "'Simulation.dust.coagulation.phi' is not set.")
        if self.grid.m is None:
            raise RuntimeError("'sim.grid.m' is not set.")

        if self.verbosity > 0:

            # Maximum acceptable error
            erracc = 1.e-13

            # Checking for sticking error
            msg = "\n"
            msg += colorize("Checking for mass conservation...\n",
                            color="yellow")
            print(msg)
            msg = colorize("    - Sticking:", color="yellow")
            print(msg)
            errmax, i, j = std.dust_f.check_mass_conservation_sticking(
                self.dust.coagulation.stick, self.dust.coagulation.stick_ind, self.grid.m)
            tup = (j, i)
            color = "red"
            if(errmax < erracc):
                color = "green"
            error = "{:9.2e}".format(errmax)
            msg = "        max. rel. error: {:}\n".format(
                colorize(error, color=color))
            msg += "        for particle collision\n"
            msg += "            m[{:d}] = {:9.2e} g    with\n".format(
                tup[0], self.grid.m[tup[0]])
            msg += "            m[{:d}] = {:9.2e} g".format(
                tup[1], self.grid.m[tup[1]])
            msg = colorize(msg)
            print(msg)

            # Checking for full fragmentation error
            msg = colorize("    - Full fragmentation:", color="yellow")
            print(msg)
            A = self.dust.coagulation.A
            eps = self.dust.coagulation.eps
            klf = self.dust.coagulation.lf_ind
            krm = self.dust.coagulation.rm_ind
            m = self.grid.m
            phi = self.dust.coagulation.phi
            errmax, i, j = std.dust_f.check_mass_conservation_full_fragmentation(
                A, klf, m, phi)
            tup = (j, i)
            color = "red"
            if(errmax < erracc):
                color = "green"
            error = "{:9.2e}".format(errmax)
            msg = "        max. rel. error: {:}\n".format(
                colorize(error, color=color))
            msg += "        for particle collision\n"
            msg += "            m[{:d}] = {:9.2e} g    with\n".format(
                tup[0], self.grid.m[tup[0]])
            msg += "            m[{:d}] = {:9.2e} g".format(
                tup[1], self.grid.m[tup[1]])
            msg = colorize(msg)
            print(msg)

            # Checking for erosion error
            msg = colorize("    - Erosion:", color="yellow")
            print(msg)
            errmax, i, j = std.dust_f.check_mass_conservation_erosion(
                A, eps, klf, krm, m, phi)
            tup = (j, i)
            color = "red"
            if(errmax < erracc):
                color = "green"
            error = "{:9.2e}".format(errmax)
            msg = "        max. rel. error: {:}\n".format(
                colorize(error, color=color))
            msg += "        for particle collision\n"
            msg += "            m[{:d}] = {:9.2e} g    with\n".format(
                tup[0], self.grid.m[tup[0]])
            msg += "            m[{:d}] = {:9.2e} g\n".format(
                tup[1], self.grid.m[tup[1]])
            msg = colorize(msg)
            print(msg)

    def initialize(self):
        '''Function initializes the simulation frame.

        Function sets all fields that are None with a standard value.
        If the grids are not set, it will call ``Simulation.makegrids()`` first.'''
        if not isinstance(self.grid.Nm, Field) or not isinstance(self.grid.Nr, Field):
            self.makegrids()

        # INTEGRATION VARIABLE
        if self.t is None:
            self.t = IntVar(self, 0., description="Time [s]")
            self.t.cfl = 0.1
            self.t.updater = std.sim.dt
            self.t.snapshots = np.logspace(3., 5., num=21, base=10.) * c.year

        # STELLAR QUANTITIES
        self._initializestar()

        # GRID QUANTITIES
        self._initializegrid()

        # GAS QUANTITIES
        self._initializegas()

        # DUST QUANTITIES
        self._initializedust()

        # INTEGRATOR
        if self.integrator is None:
            instructions = [
                Instruction(std.dust.impl_1_direct,
                            self.dust.Sigma,
                            controller={"rhs": self.dust._rhs
                                        },
                            description="Dust: implicit 1st-order direct solver"
                            ),
                Instruction(std.gas.impl_1_direct,
                            self.gas.Sigma,
                            controller={"rhs": self.gas._rhs
                                        },
                            description="Gas: implicit 1st-order direct solver"
                            ),
            ]
            self.integrator = Integrator(
                self.t, description="Default integrator")
            self.integrator.instructions = instructions
            self.integrator.preparator = std.sim.prepare_implicit_dust
            self.integrator.finalizer = std.sim.finalize_implicit_dust

        # WRITER
        if self.writer is None:
            self.writer = hdf5writer()

        # Updating the entire Simulation object including integrator finalization
        self.integrator._finalize()
        self.update()

    def _initializedust(self):
        '''Function to initialize dust quantities'''
        shape1 = (int(self.grid.Nr))
        shape2 = (int(self.grid.Nr), int(self.grid.Nm))
        shape2ravel = (int(self.grid.Nr*self.grid.Nm))
        shape2p1 = (int(self.grid.Nr)+1, int(self.grid.Nm))
        shape3 = (int(self.grid.Nr), int(
            self.grid.Nm), int(self.grid.Nm))
        # Particle size
        if self.dust.a is None:
            self.dust.a = Field(self, np.zeros(shape2),
                                description="Particle size [cm]")
            self.dust.a.updater = std.dust.a
        # Coagulation parameters
        stick, stick_ind, A, eps, lf_ind, rm_ind, phi = std.dust.coagulation_parameters(
            self)
        if self.dust.coagulation.A is None:
            self.dust.coagulation.A = Field(
                self, A, description="Fragment normalization factors", constant=True)
        if self.dust.coagulation.eps is None:
            self.dust.coagulation.eps = Field(
                self, eps, description="Remnant mass distribution", constant=True)
        if self.dust.coagulation.lf_ind is None:
            self.dust.coagulation.lf_ind = Field(
                self, lf_ind, description="Index of largest fragment", constant=True)
        if self.dust.coagulation.rm_ind is None:
            self.dust.coagulation.rm_ind = Field(
                self, rm_ind, description="Smaller index of remnant", constant=True)
        if self.dust.coagulation.phi is None:
            self.dust.coagulation.phi = Field(
                self, phi, description="Fragment distribution", constant=True)
        if self.dust.coagulation.stick is None:
            self.dust.coagulation.stick = Field(
                self, stick, description="Sticking matrix", constant=True)
        if self.dust.coagulation.stick_ind is None:
            self.dust.coagulation.stick_ind = Field(
                self, stick_ind, description="Non-zero elements of sticking matrix", constant=True)
        # Diffusivity
        if self.dust.D is None:
            self.dust.D = Field(self, np.zeros(shape2),
                                description="Diffusivity [cm²/s]")
            self.dust.D.updater = std.dust.D
        # Deltas
        if self.dust.delta.rad is None:
            delta = self.ini.gas.alpha * np.ones(shape1)
            self.dust.delta.rad = Field(
                self, delta, description="Radial mixing parameter")
        if self.dust.delta.turb is None:
            delta = self.ini.gas.alpha * np.ones(shape1)
            self.dust.delta.turb = Field(
                self, delta, description="Turbulent mixing parameter")
        if self.dust.delta.vert is None:
            delta = self.ini.gas.alpha * np.ones(shape1)
            self.dust.delta.vert = Field(
                self, delta, description="Vertical mixing parameter")
        # Vertically integrated dust to gas ratio
        if self.dust.eps is None:
            self.dust.eps = Field(self, np.zeros(
                shape1), description="Dust-to-gas ratio")
            self.dust.eps.updater = std.dust.eps
        # Fluxes
        if self.dust.Fi.adv is None:
            self.dust.Fi.adv = Field(self, np.zeros(
                shape2p1), description="Advective flux [g/cm/s]")
            self.dust.Fi.adv.updater = std.dust.F_adv
        if self.dust.Fi.diff is None:
            self.dust.Fi.diff = Field(self, np.zeros(
                shape2p1), description="Diffusive flux [g/cm/s]")
            self.dust.Fi.diff.updater = std.dust.F_diff
        if self.dust.Fi.tot is None:
            self.dust.Fi.tot = Field(self, np.zeros(
                shape2p1), description="Total flux [g/cm/s]")
            self.dust.Fi.tot.updater = std.dust.F_tot
        # Filling factor
        if self.dust.fill is None:
            self.dust.fill = Field(self, np.ones(
                shape2), description="Filling factor")
        # Scale height
        if self.dust.H is None:
            self.dust.H = Field(self, np.zeros(shape2),
                                description="Scale heights [cm]")
            self.dust.H.updater = std.dust.H
        # Kernel
        if self.dust.kernel is None:
            self.dust.kernel = Field(self, np.zeros(
                shape3), description="Collision kernel [cm²/s]")
            self.dust.kernel.updater = std.dust.kernel
        # Midplane mass density
        if self.dust.rho is None:
            self.dust.rho = Field(self, np.zeros(
                shape2), description="Midplane mass density per mass bin [g/cm³]")
            self.dust.rho.updater = std.dust.rho_midplane
        # Solid state density
        if self.dust.rhos is None:
            rhos = self.ini.dust.rhoMonomer * np.ones(shape2)
            self.dust.rhos = Field(
                self, rhos, description="Solid state density [g/cm³]")
        # Probabilities
        if self.dust.p.frag is None:
            self.dust.p.frag = Field(self, np.zeros(
                shape3), description="Fragmentation probability")
            self.dust.p.frag.updater = std.dust.p_frag
        if self.dust.p.stick is None:
            self.dust.p.stick = Field(self, np.zeros(
                shape3), description="Sticking probability")
            self.dust.p.stick.updater = std.dust.p_stick
        # Source terms
        if self.dust.S.coag is None:
            self.dust.S.coag = Field(self, np.zeros(
                shape2), description="Coagulation sources [g/cm²/s]")
            self.dust.S.coag.updater = std.dust.S_coag
        if self.dust.S.ext is None:
            self.dust.S.ext = Field(self, np.zeros(
                shape2), description="External sources [g/cm²/s]")
        if self.dust.S.hyd is None:
            self.dust.S.hyd = Field(self, np.zeros(
                shape2), description="Hydrodynamic sources [g/cm²/s]")
            self.dust.S.hyd.updater = std.dust.S_hyd
        if self.dust.S.tot is None:
            self.dust.S.tot = Field(self, np.zeros(
                shape2), description="Tot sources [g/cm²/s]")
            self.dust.S.tot.updater = std.dust.S_tot
        # Stokes number
        if self.dust.St is None:
            self.dust.St = Field(self, np.zeros(
                shape2), description="Stokes number")
            self.dust.St.updater = std.dust.St_Epstein_StokesI
        # Velocities
        if self.dust.v.frag is None:
            vfrag = self.ini.dust.vfrag * np.ones(shape1)
            self.dust.v.frag = Field(
                self, vfrag, description="Fragmentation velocity [cm/s]")
        if self.dust.v.rel.azi is None:
            self.dust.v.rel.azi = Field(self, np.zeros(
                shape3), description="Relative azimuthal velocity [cm/s]")
            self.dust.v.rel.azi.updater = std.dust.vrel_azimuthal_drift
        if self.dust.v.rel.brown is None:
            self.dust.v.rel.brown = Field(self, np.zeros(
                shape3), description="Relative Brownian motion velocity [cm/s]")
            self.dust.v.rel.brown.updater = std.dust.vrel_brownian_motion
        if self.dust.v.rel.rad is None:
            self.dust.v.rel.rad = Field(self, np.zeros(
                shape3), description="Relative radial velocity [cm/s]")
            self.dust.v.rel.rad.updater = std.dust.vrel_radial_drift
        if self.dust.v.rel.turb is None:
            self.dust.v.rel.turb = Field(self, np.zeros(
                shape3), description="Relative turbulent velocity [cm/s]")
            self.dust.v.rel.turb.updater = std.dust.vrel_turbulent_motion
        if self.dust.v.rel.vert is None:
            self.dust.v.rel.vert = Field(self, np.zeros(
                shape3), description="Relative vertical settling velocity [cm/s]")
            self.dust.v.rel.vert.updater = std.dust.vrel_vertical_settling
        if self.dust.v.rel.tot is None:
            self.dust.v.rel.tot = Field(self, np.zeros(
                shape3), description="Total relative velocity [cm/s]")
            self.dust.v.rel.tot.updater = std.dust.vrel_tot
        if self.dust.v.driftmax is None:
            self.dust.v.driftmax = Field(self, np.zeros(
                shape1), description="Maximum drift velocity [cm/s]")
            self.dust.v.driftmax.updater = std.dust.vdriftmax
        if self.dust.v.rad is None:
            self.dust.v.rad = Field(self, np.zeros(
                shape2), description="Radial velocity [cm/s]")
            self.dust.v.rad.updater = std.dust.vrad
        # Initialize dust quantities partly to calculate Sigma
        try:
            self.dust.update()
        except:
            pass
        # Floor value
        if self.dust.SigmaFloor is None:
            SigmaFloor = 0.1*std.dust.SigmaFloor(self)
            self.dust.SigmaFloor = Field(
                self, SigmaFloor, description="Floor value of surface density [g/cm²]")
        # Surface density, if not set
        if self.dust.Sigma is None:
            Sigma = std.dust.MRN_distribution(self)
            Sigma = np.where(Sigma <= self.dust.SigmaFloor,
                             0.1*self.dust.SigmaFloor,
                             Sigma)
            self.dust.Sigma = Field(
                self, Sigma, description="Surface density per mass bin [g/cm²]")
        self.dust.Sigma.differentiator = std.dust.Sigma_deriv
        self.dust.Sigma.jacobinator = std.dust.jacobian
        # Fully initialize dust quantities
        self.dust.update()
        # Hidden fields
        # We store the old values of the surface density in a hidden field
        # to calculate the fluxes through the boundaries in case of implicit integration.
        self.dust._SigmaOld = Field(
            self, self.dust.Sigma, description="Previous value of surface density [g/cm²]")
        # The right-hand side of the matrix equation is stored in a hidden field
        self.dust._rhs = Field(self, np.zeros(
            shape2ravel), description="Right-hand side of matrix equation [g/cm²]")
        # Boundary conditions
        if self.dust.boundary.inner is None:
            self.dust.boundary.inner = Boundary(
                self.grid.r,
                self.grid.ri,
                self.dust.Sigma,
                condition="const_grad"
            )
        if self.dust.boundary.outer is None:
            self.dust.boundary.outer = Boundary(
                self.grid.r[::-1],
                self.grid.ri[::-1],
                self.dust.Sigma[::-1],
                condition="val",
                value=0.1*self.dust.SigmaFloor[-1]
            )

    def _initializegas(self):
        '''Function to initialize gas quantities'''
        shape1 = (int(self.grid.Nr))
        shape1p1 = (int(self.grid.Nr)+1)
        # Turbulent alpha parameter
        if self.gas.alpha is None:
            alpha = self.ini.gas.alpha * np.ones(shape1)
            self.gas.alpha = Field(
                self, alpha, description="Turbulent alpha parameter")
        # Sound speed
        if self.gas.cs is None:
            self.gas.cs = Field(self, np.zeros(shape1),
                                description="Sound speed [cm/s]")
            self.gas.cs.updater = std.gas.cs_adiabatic
        # Pressure gradient parameter
        if self.gas.eta is None:
            self.gas.eta = Field(self, np.zeros(
                shape1), description="Pressure gradient parameter")
            self.gas.eta.updater = std.gas.eta_midplane
        # Gas flux at the cell interfaces
        if self.gas.Fi is None:
            self.gas.Fi = Field(self, np.zeros(shape1p1),
                                description="Gas flux interfaces [g/cm/s]")
            self.gas.Fi.updater = std.gas.Fi
        # Adiabatic index
        if self.gas.gamma is None:
            gamma = self.ini.gas.gamma * np.ones(shape1)
            self.gas.gamma = Field(self, gamma,
                                   description="Adiabatic index")
        # Pressure scale height
        if self.gas.Hp is None:
            self.gas.Hp = Field(self, np.zeros(shape1),
                                description="Pressure scale height [cm]")
            self.gas.Hp.updater = std.gas.Hp
        # Mean free path
        if self.gas.mfp is None:
            self.gas.mfp = Field(self, np.zeros(shape1),
                                 description="Midplane mean free path [cm]")
            self.gas.mfp.updater = std.gas.mfp_midplane
        # Mean molecular weight
        if self.gas.mu is None:
            mu = self.ini.gas.mu * np.ones(shape1)
            self.gas.mu = Field(self, mu,
                                description="Mean molecular weight [g]")
        # Midplane number density
        if self.gas.n is None:
            self.gas.n = Field(self, np.zeros(shape1),
                               description="Miplane number density [1/cm³]")
            self.gas.n.updater = std.gas.n_midplane
        # Viscosity
        if self.gas.nu is None:
            self.gas.nu = Field(self, np.zeros(shape1),
                                description="Kinematic viscosity [cm²/s]")
            self.gas.nu.updater = std.gas.nu
        # Midplane pressure
        if self.gas.P is None:
            self.gas.P = Field(self, np.zeros(shape1),
                               description="Midplane pressure [g/cm/s²]")
            self.gas.P.updater = std.gas.P_midplane
        # Midplane mass density
        if self.gas.rho is None:
            self.gas.rho = Field(self, np.zeros(shape1),
                                 description="Miplane mass density [g/cm³]")
            self.gas.rho.updater = std.gas.rho_midplane
        # Sources
        if self.gas.S.hyd is None:
            self.gas.S.hyd = Field(self, np.zeros(
                shape1), description="Hydrodynamic sources [g/cm²/s]")
            self.gas.S.hyd.updater = std.gas.S_hyd
        if self.gas.S.ext is None:
            self.gas.S.ext = Field(self, np.zeros(
                shape1), description="External sources [g/cm²/s]")
        if self.gas.S.tot is None:
            self.gas.S.tot = Field(self, np.zeros(
                shape1), description="Total sources [g/cm²/s]")
            self.gas.S.tot.updater = std.gas.S_tot
        # Floor value
        if self.gas.SigmaFloor is None:
            self.gas.SigmaFloor = Field(
                self, 1.e-100*np.ones(shape1), description="Floor value of surface density [g/cm²]")
        # Surface density
        if self.gas.Sigma is None:
            SigmaGas = np.array(std.gas.lyndenbellpringle1974(
                self.grid.r, self.ini.gas.SigmaRc, self.ini.gas.SigmaExp, self.ini.gas.Mdisk))
            SigmaGas = np.maximum(SigmaGas, self.gas.SigmaFloor)
            self.gas.Sigma = Field(self, SigmaGas,
                                   description="Surface density [g/cm²]")
        self.gas.Sigma.jacobinator = std.gas.jacobian
        # Temperature
        if self.gas.T is None:
            self.gas.T = Field(self, np.zeros(shape1),
                               description="Temperature [K]")
            self.gas.T.updater = std.gas.T_passive
        # Velocities
        # Viscous accretion velocity
        if self.gas.v.visc is None:
            self.gas.v.visc = Field(self, np.zeros(shape1),
                                    description="Viscous accretion velocity [cm/s]")
            self.gas.v.visc.updater = std.gas.vvisc
        # Radial gas velocity
        if self.gas.v.rad is None:
            self.gas.v.rad = Field(self, np.zeros(shape1),
                                   description="Radial velocity [cm/s]")
            self.gas.v.rad.updater = std.gas.vrad
        # Hidden fields
        # We store the old values of the surface density in a hidden field
        # to calculate the fluxes through the boundaries.
        self.gas._SigmaOld = Field(self, np.zeros(
            shape1), description="Previous value of surface density [g/cm²]")
        self.gas._SigmaOld[:] = self.gas.Sigma
        # The right-hand side of the matrix equation is stored in a hidden field
        self.gas._rhs = Field(self, np.zeros(
            shape1), description="Right-hand side of matrix equation [g/cm²]")

        # The dust backreaction coefficients have to be initialized before the gas,
        # since the gas velocities need them.
        # Backreaction
        if self.dust.backreaction.A is None:
            self.dust.backreaction.A = Field(
                self, np.ones(shape1), description="Pull factor")
        if self.dust.backreaction.B is None:
            self.dust.backreaction.B = Field(
                self, np.zeros(shape1), description="Push factor")

        # Initialize gas quantities
        self.gas.update()
        # Boundary conditions
        if self.gas.boundary.inner is None:
            self.gas.boundary.inner = Boundary(
                self.grid.r, self.grid.ri, self.gas.Sigma)
            self.gas.boundary.inner.setcondition("const_grad")
        if self.gas.boundary.outer is None:
            self.gas.boundary.outer = Boundary(
                self.grid.r[::-1], self.grid.ri[::-1], self.gas.Sigma[::-1])
            self.gas.boundary.outer.setcondition(
                "val", 0.1*self.gas.SigmaFloor[-1])

    def _initializegrid(self):
        '''Function to initialize grid quantities'''
        shape1 = (int(self.grid.Nr))
        # Keplerian frequency
        if self.grid.OmegaK is None:
            self.grid.OmegaK = Field(self, np.zeros(shape1),
                                     description="Keplerian frequency [1/s]")
            self.grid.OmegaK.updater = std.grid.OmegaK
        # Initialize grid quantities
        self.grid.update()

    def _initializestar(self):
        '''Function to initialize the stellar quantities'''
        # Luminosity
        if self.star.L is None:
            self.star.L = Field(self, 0., description="Luminosity [erg/s]")
            self.star.L.updater = std.star.luminosity
        # Mass
        if self.star.M is None:
            self.star.M = Field(self, self.ini.star.M,
                                description="Mass [g]")
        # Radius
        if self.star.R is None:
            self.star.R = Field(self, self.ini.star.R,
                                description="Radius [cm]")
        # Effective temperature
        if self.star.T is None:
            self.star.T = Field(self, self.ini.star.T,
                                description="Effective temperature [K]")
        # Initialize stellar quantities
        self.star.update()

    def setdustintegrator(self, scheme="explicit", method="cash-karp"):
        """Function sets the dust integrator.

        Parameters
        ----------
        scheme : string, optional, default : "explicit"
            Possible values
                {"explicit", "implicit"}
        method : string, optional, default : "cash-karp"
            Possible values for explicit integration
                {"cash-karp"}
            Possible values for implicit integration
                {"direct", "gmres", "bicgstab}"""

        if not isinstance(self.grid.Nm, Field) or not isinstance(self.grid.Nr, Field):
            raise RuntimeError(
                "The simulation frame has to be initialized before calling setdustimplicit().")

        # Get index of dust instruction
        for i, inst in enumerate(self.integrator.instructions):
            if inst.Y is self.dust.Sigma:
                break

        if scheme == "implicit":

            shape2ravel = (int(self.grid.Nr*self.grid.Nm))

            # Hidden fields
            # We store the old values of the surface density in a hidden field
            # to calculate the fluxes through the boundaries in case of implicit integration.
            self.dust._SigmaOld = Field(
                self, self.dust.Sigma, description="Previous value of surface density [g/cm²]")
            # The right-hand side of the matrix equation is stored in a hidden field
            self.dust._rhs = Field(self, np.zeros(
                shape2ravel), description="Right-hand side of matrix equation [g/cm²]")

            # Setting the Jacobinator
            self.dust.Sigma.jacobinator = std.dust.jacobian

            # Time step routine
            self.t.updater = std.sim.dt

            # Updaters
            self.dust.v.updater = ["frag", "driftmax", "rel"]
            self.dust.updater = ["delta", "rhos", "fill", "a", "St", "H",
                                 "rho", "backreaction", "v", "D", "eps", "kernel", "p", "S"]
            self.dust.S.updater = ["ext", "tot"]

            # Preparation/Finalization
            self.integrator.preparator = std.sim.prepare_implicit_dust
            self.integrator.finalizer = std.sim.finalize_implicit_dust

            # Integrator
            if method == "direct":

                inst = Instruction(std.dust.impl_1_direct,
                                   self.dust.Sigma,
                                   controller={"rhs": self.dust._rhs
                                               },
                                   description="Dust: implicit 1st-order direct solver"
                                   )
                self.integrator.instructions[i] = inst

            elif method == "gmres":
                raise NotImplementedError(
                    "GMRES method is not implemented, yet.")
            elif method == "bicgstab":
                raise NotImplementedError("BiCGSTAB is not implemented, yet.")
            else:
                raise RuntimeError("Invalid method for implicit integration.")
        elif scheme == "explicit":

            # Remove hidden fields if they exist
            if hasattr(self.dust, "_SigmaOld"):
                del self.dust._SigmaOld
            if hasattr(self.dust, "_rhs"):
                del self.dust._rhs

            # Unset Jacobian
            self.dust.Sigma.jacobinator = None

            # Updaters
            self.dust.v.updater = ["frag", "driftmax", "rad", "rel"]
            self.dust.updater = ["delta", "rhos", "fill", "a", "St", "H",
                                 "rho", "backreaction", "v", "D", "eps", "Fi", "kernel", "p", "S"]
            self.dust.S.updater = ["coag", "hyd", "ext", "tot"]

            # Preparation/Finalization
            self.integrator.preparator = std.sim.prepare_explicit_dust
            self.integrator.finalizer = std.sim.finalize_explicit_dust

            if method == "cash-karp":

                # Adaptive time step routine
                self.t.updater = std.sim.dt_adaptive

                # Instruction
                inst = Instruction(schemes.expl_5_cash_karp_adptv,
                                   self.dust.Sigma,
                                   controller={"dYdx": self.dust.S.tot,
                                               "eps": 0.1,
                                               "S": 0.9,
                                               },
                                   description="Dust: explicit 5th-order adaptive Cash-Karp method"
                                   )
                self.integrator.instructions[i] = inst
                self.t.suggest(1.*c.year)

            else:
                raise RuntimeError("Invalid method for explicit integration.")
        else:
            raise RuntimeError("Unknown integration scheme.")

        self.integrator._finalize()
        self.update()

        if self.verbosity > 0:
            msg = "Setting dust integrator\n    scheme: {}\n    method: {}".format(
                colorize(scheme, "blue"), colorize(method, "blue"))
            print(msg)