コード例 #1
0
def main():
    logmgr = LogManager("mylog.dat", "w")  # , comm=...

    # set a run property
    logmgr.set_constant("myconst", uniform(0, 1))

    add_run_info(logmgr)
    add_general_quantities(logmgr)
    add_simulation_quantities(logmgr)

    vis_timer = IntervalTimer("t_vis", "Time spent visualizing")
    logmgr.add_quantity(vis_timer)
    logmgr.add_quantity(Fifteen("fifteen"))
    logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

    for istep in range(200):
        logmgr.tick_before()

        dt = uniform(0.01, 0.1)
        set_dt(logmgr, dt)
        sleep(dt)

        # Illustrate custom timers
        if istep % 10 == 0:
            with vis_timer.start_sub_timer():
                sleep(0.05)

        # Illustrate warnings capture
        if uniform(0, 1) < 0.05:
            warn("Oof. Something went awry.")

        logmgr.tick_after()

    logmgr.close()
コード例 #2
0
def add_package_versions(mgr: LogManager,
                         path_to_version_sh: str = None) -> None:
    """Add the output of the emirge version.sh script to the log.

    Parameters
    ----------
    mgr
        The :class:`logpyle.LogManager` to add the versions to.

    path_to_version_sh
        Path to emirge's version.sh script. The function will attempt to find this
        script automatically if this argument is not specified.

    """
    import subprocess
    from warnings import warn

    output = None

    # Find emirge's version.sh in any parent directory
    if path_to_version_sh is None:
        import pathlib
        import mirgecom

        p = pathlib.Path(mirgecom.__file__).resolve()

        for d in p.parents:
            candidate = pathlib.Path(d).joinpath("version.sh")
            if candidate.is_file():
                with open(candidate) as f:
                    if "emirge" in f.read():
                        path_to_version_sh = str(candidate)
                        break

    if path_to_version_sh is None:
        warn("Could not find emirge's version.sh.")

    else:
        try:
            output = subprocess.check_output(path_to_version_sh)
        except OSError as e:
            warn("Could not record emirge's package versions: " + str(e))

    mgr.set_constant("emirge_package_versions", output)
コード例 #3
0
def main(write_output=True):
    from grudge.backends import guess_run_context
    rcon = guess_run_context(
        #["cuda"]
    )

    gamma = 1.4

    # at A=1 we have case of isentropic vortex, source terms
    # arise for other values
    densityA = 2.0

    from grudge.tools import EOCRecorder, to_obj_array
    eoc_rec = EOCRecorder()

    if rcon.is_head_rank:
        from grudge.mesh import \
                make_rect_mesh, \
                make_centered_regular_rect_mesh

        refine = 1
        mesh = make_centered_regular_rect_mesh((0, -5), (10, 5),
                                               n=(9, 9),
                                               post_refine_factor=refine)
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    for order in [4, 5]:
        discr = rcon.make_discretization(
            mesh_data,
            order=order,
            debug=[  #"cuda_no_plan",
                #"print_op_code"
            ],
            default_scalar_type=numpy.float64)

        from grudge.visualization import SiloVisualizer, VtkVisualizer
        #vis = VtkVisualizer(discr, rcon, "vortex-%d" % order)
        vis = SiloVisualizer(discr, rcon)

        vortex = Vortex(beta=5,
                        gamma=gamma,
                        center=[5, 0],
                        velocity=[1, 0],
                        densityA=densityA)
        fields = vortex.volume_interpolant(0, discr)
        sources = SourceTerms(beta=5,
                              gamma=gamma,
                              center=[5, 0],
                              velocity=[1, 0],
                              densityA=densityA)

        from grudge.models.gas_dynamics import (GasDynamicsOperator,
                                                GammaLawEOS)
        from grudge.mesh import BTAG_ALL

        op = GasDynamicsOperator(dimensions=2,
                                 mu=0.0,
                                 prandtl=0.72,
                                 spec_gas_const=287.1,
                                 equation_of_state=GammaLawEOS(vortex.gamma),
                                 bc_inflow=vortex,
                                 bc_outflow=vortex,
                                 bc_noslip=vortex,
                                 inflow_tag=BTAG_ALL,
                                 source=sources)

        euler_ex = op.bind(discr)

        max_eigval = [0]

        def rhs(t, q):
            ode_rhs, speed = euler_ex(t, q)
            max_eigval[0] = speed
            return ode_rhs

        rhs(0, fields)

        if rcon.is_head_rank:
            print("---------------------------------------------")
            print("order %d" % order)
            print("---------------------------------------------")
            print("#elements=", len(mesh.elements))

        # limiter setup -------------------------------------------------------
        from grudge.models.gas_dynamics import SlopeLimiter1NEuler
        limiter = SlopeLimiter1NEuler(discr, gamma, 2, op)

        # time stepper --------------------------------------------------------
        from grudge.timestep import SSPRK3TimeStepper, RK4TimeStepper
        #stepper = SSPRK3TimeStepper(limiter=limiter)
        #stepper = SSPRK3TimeStepper()
        stepper = RK4TimeStepper()

        # diagnostics setup ---------------------------------------------------
        from logpyle import LogManager, add_general_quantities, \
                add_simulation_quantities, add_run_info

        if write_output:
            log_file_name = "euler-%d.dat" % order
        else:
            log_file_name = None

        logmgr = LogManager(log_file_name, "w", rcon.communicator)
        add_run_info(logmgr)
        add_general_quantities(logmgr)
        add_simulation_quantities(logmgr)
        discr.add_instrumentation(logmgr)
        stepper.add_instrumentation(logmgr)

        logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

        # timestep loop -------------------------------------------------------
        t = 0

        #fields = limiter(fields)

        try:
            from grudge.timestep import times_and_steps
            step_it = times_and_steps(
                final_time=.1,
                #max_steps=500,
                logmgr=logmgr,
                max_dt_getter=lambda t: 0.4 * op.estimate_timestep(
                    discr, stepper=stepper, t=t, max_eigenvalue=max_eigval[0]))

            for step, t, dt in step_it:
                if step % 1 == 0 and write_output:
                    #if False:
                    visf = vis.make_file("vortex-%d-%04d" % (order, step))

                    true_fields = vortex.volume_interpolant(t, discr)

                    #rhs_fields = rhs(t, fields)

                    from pyvisfile.silo import DB_VARTYPE_VECTOR
                    vis.add_data(
                        visf,
                        [
                            ("rho",
                             discr.convert_volume(op.rho(fields),
                                                  kind="numpy")),
                            ("e",
                             discr.convert_volume(op.e(fields), kind="numpy")),
                            ("rho_u",
                             discr.convert_volume(op.rho_u(fields),
                                                  kind="numpy")),
                            ("u",
                             discr.convert_volume(op.u(fields), kind="numpy")),

                            #("true_rho", discr.convert_volume(op.rho(true_fields), kind="numpy")),
                            #("true_e", discr.convert_volume(op.e(true_fields), kind="numpy")),
                            #("true_rho_u", discr.convert_volume(op.rho_u(true_fields), kind="numpy")),
                            #("true_u", discr.convert_volume(op.u(true_fields), kind="numpy")),

                            #("rhs_rho", discr.convert_volume(op.rho(rhs_fields), kind="numpy")),
                            #("rhs_e", discr.convert_volume(op.e(rhs_fields), kind="numpy")),
                            #("rhs_rho_u", discr.convert_volume(op.rho_u(rhs_fields), kind="numpy")),
                        ],
                        expressions=[
                            #("diff_rho", "rho-true_rho"),
                            #("diff_e", "e-true_e"),
                            #("diff_rho_u", "rho_u-true_rho_u", DB_VARTYPE_VECTOR),
                            ("p", "0.4*(e- 0.5*(rho_u*u))"),
                        ],
                        time=t,
                        step=step)
                    visf.close()

                fields = stepper(fields, t, dt, rhs)

            true_fields = vortex.volume_interpolant(t, discr)
            l2_error = discr.norm(fields - true_fields)
            l2_error_rho = discr.norm(op.rho(fields) - op.rho(true_fields))
            l2_error_e = discr.norm(op.e(fields) - op.e(true_fields))
            l2_error_rhou = discr.norm(
                op.rho_u(fields) - op.rho_u(true_fields))
            l2_error_u = discr.norm(op.u(fields) - op.u(true_fields))

            eoc_rec.add_data_point(order, l2_error_rho)
            print()
            print(eoc_rec.pretty_print("P.Deg.", "L2 Error"))

            logmgr.set_constant("l2_error", l2_error)
            logmgr.set_constant("l2_error_rho", l2_error_rho)
            logmgr.set_constant("l2_error_e", l2_error_e)
            logmgr.set_constant("l2_error_rhou", l2_error_rhou)
            logmgr.set_constant("l2_error_u", l2_error_u)
            logmgr.set_constant("refinement", refine)

        finally:
            if write_output:
                vis.close()

            logmgr.close()
            discr.close()
コード例 #4
0
ファイル: vortex.py プロジェクト: VincentWells/grudge-1
def main(write_output=True):
    from pytools import add_python_path_relative_to_script
    add_python_path_relative_to_script("..")

    from grudge.backends import guess_run_context
    rcon = guess_run_context()

    from grudge.tools import EOCRecorder
    eoc_rec = EOCRecorder()

    if rcon.is_head_rank:
        from grudge.mesh.generator import \
                make_rect_mesh, \
                make_centered_regular_rect_mesh

        refine = 4
        mesh = make_centered_regular_rect_mesh((0, -5), (10, 5),
                                               n=(9, 9),
                                               post_refine_factor=refine)
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    for order in [3, 4, 5]:
        from gas_dynamics_initials import Vortex
        flow = Vortex()

        from grudge.models.gas_dynamics import (GasDynamicsOperator,
                                                PolytropeEOS, GammaLawEOS)

        from grudge.mesh import BTAG_ALL
        # works equally well for GammaLawEOS
        op = GasDynamicsOperator(dimensions=2,
                                 mu=flow.mu,
                                 prandtl=flow.prandtl,
                                 spec_gas_const=flow.spec_gas_const,
                                 equation_of_state=PolytropeEOS(flow.gamma),
                                 bc_inflow=flow,
                                 bc_outflow=flow,
                                 bc_noslip=flow,
                                 inflow_tag=BTAG_ALL,
                                 source=None)

        discr = rcon.make_discretization(mesh_data,
                                         order=order,
                                         default_scalar_type=numpy.float64,
                                         quad_min_degrees={
                                             "gasdyn_vol": 3 * order,
                                             "gasdyn_face": 3 * order,
                                         },
                                         tune_for=op.sym_operator(),
                                         debug=["cuda_no_plan"])

        from grudge.visualization import SiloVisualizer, VtkVisualizer
        vis = VtkVisualizer(discr, rcon, "vortex-%d" % order)
        #vis = SiloVisualizer(discr, rcon)

        fields = flow.volume_interpolant(0, discr)

        euler_ex = op.bind(discr)

        max_eigval = [0]

        def rhs(t, q):
            ode_rhs, speed = euler_ex(t, q)
            max_eigval[0] = speed
            return ode_rhs

        rhs(0, fields)

        if rcon.is_head_rank:
            print("---------------------------------------------")
            print("order %d" % order)
            print("---------------------------------------------")
            print("#elements=", len(mesh.elements))

        # limiter ------------------------------------------------------------
        from grudge.models.gas_dynamics import SlopeLimiter1NEuler
        limiter = SlopeLimiter1NEuler(discr, flow.gamma, 2, op)

        from grudge.timestep.runge_kutta import SSP3TimeStepper
        #stepper = SSP3TimeStepper(limiter=limiter)
        stepper = SSP3TimeStepper(
            vector_primitive_factory=discr.get_vector_primitive_factory())

        #from grudge.timestep import RK4TimeStepper
        #stepper = RK4TimeStepper()

        # diagnostics setup ---------------------------------------------------
        from logpyle import LogManager, add_general_quantities, \
                add_simulation_quantities, add_run_info

        if write_output:
            log_file_name = "euler-%d.dat" % order
        else:
            log_file_name = None

        logmgr = LogManager(log_file_name, "w", rcon.communicator)
        add_run_info(logmgr)
        add_general_quantities(logmgr)
        add_simulation_quantities(logmgr)
        discr.add_instrumentation(logmgr)
        stepper.add_instrumentation(logmgr)

        logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

        # timestep loop -------------------------------------------------------
        try:
            final_time = flow.final_time
            from grudge.timestep import times_and_steps
            step_it = times_and_steps(
                final_time=final_time,
                logmgr=logmgr,
                max_dt_getter=lambda t: op.estimate_timestep(
                    discr, stepper=stepper, t=t, max_eigenvalue=max_eigval[0]))

            print("run until t=%g" % final_time)
            for step, t, dt in step_it:
                if step % 10 == 0 and write_output:
                    #if False:
                    visf = vis.make_file("vortex-%d-%04d" % (order, step))

                    #true_fields = vortex.volume_interpolant(t, discr)

                    from pyvisfile.silo import DB_VARTYPE_VECTOR
                    vis.add_data(
                        visf,
                        [
                            ("rho",
                             discr.convert_volume(op.rho(fields),
                                                  kind="numpy")),
                            ("e",
                             discr.convert_volume(op.e(fields), kind="numpy")),
                            ("rho_u",
                             discr.convert_volume(op.rho_u(fields),
                                                  kind="numpy")),
                            ("u",
                             discr.convert_volume(op.u(fields), kind="numpy")),

                            #("true_rho", discr.convert_volume(op.rho(true_fields), kind="numpy")),
                            #("true_e", discr.convert_volume(op.e(true_fields), kind="numpy")),
                            #("true_rho_u", discr.convert_volume(op.rho_u(true_fields), kind="numpy")),
                            #("true_u", discr.convert_volume(op.u(true_fields), kind="numpy")),

                            #("rhs_rho", discr.convert_volume(op.rho(rhs_fields), kind="numpy")),
                            #("rhs_e", discr.convert_volume(op.e(rhs_fields), kind="numpy")),
                            #("rhs_rho_u", discr.convert_volume(op.rho_u(rhs_fields), kind="numpy")),
                        ],
                        #expressions=[
                        #("diff_rho", "rho-true_rho"),
                        #("diff_e", "e-true_e"),
                        #("diff_rho_u", "rho_u-true_rho_u", DB_VARTYPE_VECTOR),

                        #("p", "0.4*(e- 0.5*(rho_u*u))"),
                        #],
                        time=t,
                        step=step)
                    visf.close()

                fields = stepper(fields, t, dt, rhs)
                #fields = limiter(fields)

                assert not numpy.isnan(numpy.sum(fields[0]))

            true_fields = flow.volume_interpolant(final_time, discr)
            l2_error = discr.norm(fields - true_fields)
            l2_error_rho = discr.norm(op.rho(fields) - op.rho(true_fields))
            l2_error_e = discr.norm(op.e(fields) - op.e(true_fields))
            l2_error_rhou = discr.norm(
                op.rho_u(fields) - op.rho_u(true_fields))
            l2_error_u = discr.norm(op.u(fields) - op.u(true_fields))

            eoc_rec.add_data_point(order, l2_error)
            print()
            print(eoc_rec.pretty_print("P.Deg.", "L2 Error"))

            logmgr.set_constant("l2_error", l2_error)
            logmgr.set_constant("l2_error_rho", l2_error_rho)
            logmgr.set_constant("l2_error_e", l2_error_e)
            logmgr.set_constant("l2_error_rhou", l2_error_rhou)
            logmgr.set_constant("l2_error_u", l2_error_u)
            logmgr.set_constant("refinement", refine)

        finally:
            if write_output:
                vis.close()

            logmgr.close()
            discr.close()

    # after order loop
    assert eoc_rec.estimate_order_of_convergence()[0, 1] > 6
コード例 #5
0
def logmgr_add_cl_device_info(logmgr: LogManager, queue: cl.CommandQueue):
    """Add information about the OpenCL device to the log."""
    dev = queue.device
    logmgr.set_constant("cl_device_name", str(dev))
    logmgr.set_constant("cl_device_version", dev.version)
    logmgr.set_constant("cl_platform_version", dev.platform.version)
コード例 #6
0
ファイル: shearflow.py プロジェクト: VincentWells/grudge-1
def main():
    from grudge.backends import guess_run_context
    rcon = guess_run_context(
        #["cuda"]
    )

    from grudge.tools import EOCRecorder, to_obj_array
    eoc_rec = EOCRecorder()

    def boundary_tagger(vertices, el, face_nr, all_v):
        return ["inflow"]

    if rcon.is_head_rank:
        from grudge.mesh import make_rect_mesh, \
                               make_centered_regular_rect_mesh
        #mesh = make_rect_mesh((0,0), (10,1), max_area=0.01)
        refine = 1
        mesh = make_centered_regular_rect_mesh(
            (0, 0),
            (10, 1),
            n=(20, 4),
            #periodicity=(True, False),
            post_refine_factor=refine,
            boundary_tagger=boundary_tagger)
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    for order in [3]:
        discr = rcon.make_discretization(mesh_data,
                                         order=order,
                                         default_scalar_type=numpy.float64)

        from grudge.visualization import SiloVisualizer, VtkVisualizer
        #vis = VtkVisualizer(discr, rcon, "shearflow-%d" % order)
        vis = SiloVisualizer(discr, rcon)

        shearflow = SteadyShearFlow()
        fields = shearflow.volume_interpolant(0, discr)
        gamma, mu, prandtl, spec_gas_const = shearflow.properties()

        from grudge.models.gas_dynamics import GasDynamicsOperator
        op = GasDynamicsOperator(dimensions=2,
                                 gamma=gamma,
                                 mu=mu,
                                 prandtl=prandtl,
                                 spec_gas_const=spec_gas_const,
                                 bc_inflow=shearflow,
                                 bc_outflow=shearflow,
                                 bc_noslip=shearflow,
                                 inflow_tag="inflow",
                                 outflow_tag="outflow",
                                 noslip_tag="noslip")

        navierstokes_ex = op.bind(discr)

        max_eigval = [0]

        def rhs(t, q):
            ode_rhs, speed = navierstokes_ex(t, q)
            max_eigval[0] = speed
            return ode_rhs

        # needed to get first estimate of maximum eigenvalue
        rhs(0, fields)

        if rcon.is_head_rank:
            print("---------------------------------------------")
            print("order %d" % order)
            print("---------------------------------------------")
            print("#elements=", len(mesh.elements))

        from grudge.timestep import RK4TimeStepper
        stepper = RK4TimeStepper()

        # diagnostics setup ---------------------------------------------------
        from logpyle import LogManager, add_general_quantities, \
                add_simulation_quantities, add_run_info

        logmgr = LogManager("navierstokes-cpu-%d-%d.dat" % (order, refine),
                            "w", rcon.communicator)
        add_run_info(logmgr)
        add_general_quantities(logmgr)
        add_simulation_quantities(logmgr)
        discr.add_instrumentation(logmgr)
        stepper.add_instrumentation(logmgr)

        logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

        # timestep loop -------------------------------------------------------
        try:
            from grudge.timestep import times_and_steps
            step_it = times_and_steps(
                final_time=0.3,
                #max_steps=500,
                logmgr=logmgr,
                max_dt_getter=lambda t: op.estimate_timestep(
                    discr, stepper=stepper, t=t, max_eigenvalue=max_eigval[0]))

            for step, t, dt in step_it:
                if step % 10 == 0:
                    #if False:
                    visf = vis.make_file("shearflow-%d-%04d" % (order, step))

                    #true_fields = shearflow.volume_interpolant(t, discr)

                    from pyvisfile.silo import DB_VARTYPE_VECTOR
                    vis.add_data(
                        visf,
                        [
                            ("rho",
                             discr.convert_volume(op.rho(fields),
                                                  kind="numpy")),
                            ("e",
                             discr.convert_volume(op.e(fields), kind="numpy")),
                            ("rho_u",
                             discr.convert_volume(op.rho_u(fields),
                                                  kind="numpy")),
                            ("u",
                             discr.convert_volume(op.u(fields), kind="numpy")),

                            #("true_rho", discr.convert_volume(op.rho(true_fields), kind="numpy")),
                            #("true_e", discr.convert_volume(op.e(true_fields), kind="numpy")),
                            #("true_rho_u", discr.convert_volume(op.rho_u(true_fields), kind="numpy")),
                            #("true_u", discr.convert_volume(op.u(true_fields), kind="numpy")),
                        ],
                        expressions=[
                            #("diff_rho", "rho-true_rho"),
                            #("diff_e", "e-true_e"),
                            #("diff_rho_u", "rho_u-true_rho_u", DB_VARTYPE_VECTOR),
                            ("p", "0.4*(e- 0.5*(rho_u*u))"),
                        ],
                        time=t,
                        step=step)
                    visf.close()

                fields = stepper(fields, t, dt, rhs)

            true_fields = shearflow.volume_interpolant(t, discr)
            l2_error = discr.norm(op.u(fields) - op.u(true_fields))
            eoc_rec.add_data_point(order, l2_error)
            print()
            print(eoc_rec.pretty_print("P.Deg.", "L2 Error"))

            logmgr.set_constant("l2_error", l2_error)

        finally:
            vis.close()
            logmgr.save()
            discr.close()
コード例 #7
0
def main(write_output=True):
    from pytools import add_python_path_relative_to_script
    add_python_path_relative_to_script("..")

    from grudge.backends import guess_run_context
    rcon = guess_run_context()

    from grudge.tools import EOCRecorder
    eoc_rec = EOCRecorder()

    if rcon.is_head_rank:
        from grudge.mesh.generator import \
                make_rect_mesh, \
                make_centered_regular_rect_mesh

        refine = 4
        mesh = make_centered_regular_rect_mesh((0, -5), (10, 5),
                                               n=(9, 9),
                                               post_refine_factor=refine)
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    # a second mesh to regrid to
    if rcon.is_head_rank:
        from grudge.mesh.generator import \
                make_rect_mesh, \
                make_centered_regular_rect_mesh

        refine = 4
        mesh2 = make_centered_regular_rect_mesh((0, -5), (10, 5),
                                                n=(8, 8),
                                                post_refine_factor=refine)
        mesh_data2 = rcon.distribute_mesh(mesh2)
    else:
        mesh_data2 = rcon.receive_mesh()

    for order in [3, 4]:
        discr = rcon.make_discretization(mesh_data,
                                         order=order,
                                         default_scalar_type=numpy.float64,
                                         quad_min_degrees={
                                             "gasdyn_vol": 3 * order,
                                             "gasdyn_face": 3 * order,
                                         })

        discr2 = rcon.make_discretization(mesh_data2,
                                          order=order,
                                          default_scalar_type=numpy.float64,
                                          quad_min_degrees={
                                              "gasdyn_vol": 3 * order,
                                              "gasdyn_face": 3 * order,
                                          })

        from grudge.visualization import SiloVisualizer, VtkVisualizer
        vis = VtkVisualizer(discr, rcon, "vortex-%d" % order)
        #vis = SiloVisualizer(discr, rcon)

        from gas_dynamics_initials import Vortex
        vortex = Vortex()
        fields = vortex.volume_interpolant(0, discr)

        from grudge.models.gas_dynamics import GasDynamicsOperator
        from grudge.mesh import BTAG_ALL

        op = GasDynamicsOperator(dimensions=2,
                                 gamma=vortex.gamma,
                                 mu=vortex.mu,
                                 prandtl=vortex.prandtl,
                                 spec_gas_const=vortex.spec_gas_const,
                                 bc_inflow=vortex,
                                 bc_outflow=vortex,
                                 bc_noslip=vortex,
                                 inflow_tag=BTAG_ALL,
                                 source=None)

        euler_ex = op.bind(discr)

        max_eigval = [0]

        def rhs(t, q):
            ode_rhs, speed = euler_ex(t, q)
            max_eigval[0] = speed
            return ode_rhs

        rhs(0, fields)

        if rcon.is_head_rank:
            print("---------------------------------------------")
            print("order %d" % order)
            print("---------------------------------------------")
            print("#elements for mesh 1 =", len(mesh.elements))
            print("#elements for mesh 2 =", len(mesh2.elements))

        # limiter ------------------------------------------------------------
        from grudge.models.gas_dynamics import SlopeLimiter1NEuler
        limiter = SlopeLimiter1NEuler(discr, vortex.gamma, 2, op)

        from grudge.timestep import SSPRK3TimeStepper
        #stepper = SSPRK3TimeStepper(limiter=limiter)
        stepper = SSPRK3TimeStepper()

        #from grudge.timestep import RK4TimeStepper
        #stepper = RK4TimeStepper()

        # diagnostics setup ---------------------------------------------------
        from logpyle import LogManager, add_general_quantities, \
                add_simulation_quantities, add_run_info

        if write_output:
            log_file_name = "euler-%d.dat" % order
        else:
            log_file_name = None

        logmgr = LogManager(log_file_name, "w", rcon.communicator)
        add_run_info(logmgr)
        add_general_quantities(logmgr)
        add_simulation_quantities(logmgr)
        discr.add_instrumentation(logmgr)
        stepper.add_instrumentation(logmgr)

        logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

        # timestep loop -------------------------------------------------------
        try:
            final_time = 0.2
            from grudge.timestep import times_and_steps
            step_it = times_and_steps(
                final_time=final_time,
                logmgr=logmgr,
                max_dt_getter=lambda t: op.estimate_timestep(
                    discr, stepper=stepper, t=t, max_eigenvalue=max_eigval[0]))

            for step, t, dt in step_it:
                if step % 10 == 0 and write_output:
                    #if False:
                    visf = vis.make_file("vortex-%d-%04d" % (order, step))

                    #true_fields = vortex.volume_interpolant(t, discr)

                    from pyvisfile.silo import DB_VARTYPE_VECTOR
                    vis.add_data(
                        visf,
                        [
                            ("rho",
                             discr.convert_volume(op.rho(fields),
                                                  kind="numpy")),
                            ("e",
                             discr.convert_volume(op.e(fields), kind="numpy")),
                            ("rho_u",
                             discr.convert_volume(op.rho_u(fields),
                                                  kind="numpy")),
                            ("u",
                             discr.convert_volume(op.u(fields), kind="numpy")),

                            #("true_rho", discr.convert_volume(op.rho(true_fields), kind="numpy")),
                            #("true_e", discr.convert_volume(op.e(true_fields), kind="numpy")),
                            #("true_rho_u", discr.convert_volume(op.rho_u(true_fields), kind="numpy")),
                            #("true_u", discr.convert_volume(op.u(true_fields), kind="numpy")),

                            #("rhs_rho", discr.convert_volume(op.rho(rhs_fields), kind="numpy")),
                            #("rhs_e", discr.convert_volume(op.e(rhs_fields), kind="numpy")),
                            #("rhs_rho_u", discr.convert_volume(op.rho_u(rhs_fields), kind="numpy")),
                        ],
                        #expressions=[
                        #("diff_rho", "rho-true_rho"),
                        #("diff_e", "e-true_e"),
                        #("diff_rho_u", "rho_u-true_rho_u", DB_VARTYPE_VECTOR),

                        #("p", "0.4*(e- 0.5*(rho_u*u))"),
                        #],
                        time=t,
                        step=step)
                    visf.close()

                fields = stepper(fields, t, dt, rhs)
                #fields = limiter(fields)

                #regrid to discr2 at some arbitrary time
                if step == 21:

                    #get interpolated fields
                    fields = discr.get_regrid_values(fields,
                                                     discr2,
                                                     dtype=None,
                                                     use_btree=True,
                                                     thresh=1e-8)
                    #get new stepper (old one has reference to discr
                    stepper = SSPRK3TimeStepper()
                    #new bind
                    euler_ex = op.bind(discr2)
                    #new rhs
                    max_eigval = [0]

                    def rhs(t, q):
                        ode_rhs, speed = euler_ex(t, q)
                        max_eigval[0] = speed
                        return ode_rhs

                    rhs(t + dt, fields)
                    #add logmanager
                    #discr2.add_instrumentation(logmgr)
                    #new step_it
                    step_it = times_and_steps(
                        final_time=final_time,
                        logmgr=logmgr,
                        max_dt_getter=lambda t: op.estimate_timestep(
                            discr2,
                            stepper=stepper,
                            t=t,
                            max_eigenvalue=max_eigval[0]))

                    #new visualization
                    vis.close()
                    vis = VtkVisualizer(discr2, rcon,
                                        "vortexNewGrid-%d" % order)
                    discr = discr2

                assert not numpy.isnan(numpy.sum(fields[0]))

            true_fields = vortex.volume_interpolant(final_time, discr)
            l2_error = discr.norm(fields - true_fields)
            l2_error_rho = discr.norm(op.rho(fields) - op.rho(true_fields))
            l2_error_e = discr.norm(op.e(fields) - op.e(true_fields))
            l2_error_rhou = discr.norm(
                op.rho_u(fields) - op.rho_u(true_fields))
            l2_error_u = discr.norm(op.u(fields) - op.u(true_fields))

            eoc_rec.add_data_point(order, l2_error)
            print()
            print(eoc_rec.pretty_print("P.Deg.", "L2 Error"))

            logmgr.set_constant("l2_error", l2_error)
            logmgr.set_constant("l2_error_rho", l2_error_rho)
            logmgr.set_constant("l2_error_e", l2_error_e)
            logmgr.set_constant("l2_error_rhou", l2_error_rhou)
            logmgr.set_constant("l2_error_u", l2_error_u)
            logmgr.set_constant("refinement", refine)

        finally:
            if write_output:
                vis.close()

            logmgr.close()
            discr.close()