Exemple #1
0
    def copy_massmatrix_into_dat(self):

        # Copy the velocity mass matrix into a Dat
        vmat = self.imass_velocity.handle
        dofs_per_entity = self.U.fiat_element.entity_dofs()
        dofs_per_entity = sum(
            self.mesh.make_dofs_per_plex_entity(dofs_per_entity))
        arity = dofs_per_entity * self.U.topological.dim
        self.velocity_mass_asdat = Dat(DataSet(self.mesh.cell_set,
                                               arity * arity),
                                       dtype='double')
        istart, iend = vmat.getOwnershipRange()
        idxs = [
            PETSc.IS().createGeneral(np.arange(i, i + arity, dtype=np.int32),
                                     comm=PETSc.COMM_SELF)
            for i in range(istart, iend, arity)
        ]
        submats = vmat.getSubMatrices(idxs, idxs)
        for i, m in enumerate(submats):
            self.velocity_mass_asdat.data[i] = m[:, :].flatten()
        info("Computed velocity mass matrix")

        # Copy the stress mass matrix into a Dat
        smat = self.imass_stress.handle
        dofs_per_entity = self.S.fiat_element.entity_dofs()
        dofs_per_entity = sum(
            self.mesh.make_dofs_per_plex_entity(dofs_per_entity))
        arity = dofs_per_entity * self.S.topological.dim
        self.stress_mass_asdat = Dat(DataSet(self.mesh.cell_set,
                                             arity * arity),
                                     dtype='double')
        istart, iend = smat.getOwnershipRange()
        idxs = [
            PETSc.IS().createGeneral(np.arange(i, i + arity, dtype=np.int32),
                                     comm=PETSc.COMM_SELF)
            for i in range(istart, iend, arity)
        ]
        submats = smat.getSubMatrices(idxs, idxs)
        for i, m in enumerate(submats):
            self.stress_mass_asdat.data[i] = m[:, :].flatten()
        info("Computed stress mass matrix")
Exemple #2
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    def explosive_source_lf4(self,
                             T=2.5,
                             TS=0,
                             Lx=300.0,
                             Ly=150.0,
                             h=2.5,
                             cn=0.05,
                             mesh_file=None,
                             output=1,
                             poly_order=2,
                             params=None):

        tile_size = params['tile_size']
        num_unroll = params['num_unroll']
        extra_halo = params['extra_halo']
        part_mode = params['partitioning']
        explicit_mode = params['explicit_mode']

        if explicit_mode:
            fusion_scheme = FusionSchemes.get(explicit_mode, part_mode,
                                              tile_size)
            num_solves, params['explicit_mode'] = fusion_scheme
        else:
            num_solves = ElasticLF4.num_solves

        if mesh_file:
            mesh = Mesh(mesh_file)
        else:
            mesh = RectangleMesh(int(Lx / h), int(Ly / h), Lx, Ly)

        set_log_level(INFO)

        kwargs = {}
        if params['mode'] in ['tile', 'only_tile']:
            s_depth = calculate_sdepth(num_solves, num_unroll, extra_halo)
            if part_mode == 'metis':
                kwargs['reorder'] = ('metis-rcm', mesh.num_cells() / tile_size)
        else:
            s_depth = 1
        # FIXME: need s_depth in firedrake to be able to use this
        # kwargs['s_depth'] = s_depth
        params['s_depth'] = s_depth

        mesh.topology.init(**kwargs)
        slope(mesh, debug=True)

        # Instantiate the model
        self.elastic = ElasticLF4(mesh, "DG", poly_order, 2, output, params)

        info("S-depth used: %d" % s_depth)
        info("Polynomial order: %d" % poly_order)

        # Constants
        self.elastic.density = 1.0
        self.elastic.mu = 3600.0
        self.elastic.l = 3599.3664

        self.Vp = Vp(self.elastic.mu, self.elastic.l, self.elastic.density)
        self.Vs = Vs(self.elastic.mu, self.elastic.density)
        info("P-wave velocity: %f" % self.Vp)
        info("S-wave velocity: %f" % self.Vs)

        self.dx = h
        self.courant_number = cn
        self.elastic.dt = cfl_dt(self.dx, self.Vp, self.courant_number)
        info("Using a timestep of %f" % self.elastic.dt)

        # Source
        exp_area = (44.5, 45.5, Ly - 1.5, Ly - 0.5)
        if poly_order == 1:
            # Adjust explosion area
            exp_area = (149.5, 150.5, Ly - 1.5, Ly - 0.5)
        a = 159.42
        self.elastic.source_expression = Expression(((
            "x[0] >= %f && x[0] <= %f && x[1] >= %f && x[1] <= %f ? (-1.0 + 2*a*pow(t - 0.3, 2))*exp(-a*pow(t - 0.3, 2)) : 0.0"
            % exp_area, "0.0"
        ), ("0.0",
            "x[0] >= %f && x[0] <= %f && x[1] >= %f && x[1] <= %f ? (-1.0 + 2*a*pow(t - 0.3, 2))*exp(-a*pow(t - 0.3, 2)) : 0.0"
            % exp_area)),
                                                    a=a,
                                                    t=0)
        self.elastic.source_function = Function(self.elastic.S)
        self.elastic.source = self.elastic.source_expression

        # Absorption
        F = FunctionSpace(mesh, "DG", poly_order, name='F')
        self.elastic.absorption_function = Function(F)
        self.elastic.absorption = Expression(
            "x[0] <= 20 || x[0] >= %f || x[1] <= 20.0 ? 1000 : 0" %
            (Lx - 20, ))

        # Initial conditions
        uic = Expression(('0.0', '0.0'))
        self.elastic.u0.assign(Function(self.elastic.U).interpolate(uic))
        sic = Expression((('0', '0'), ('0', '0')))
        self.elastic.s0.assign(Function(self.elastic.S).interpolate(sic))

        # Run the simulation
        start, end, ntimesteps, u1, s1 = self.elastic.run(T, TS=TS)

        # Print runtime summary
        output_time(start,
                    end,
                    tofile=params['tofile'],
                    verbose=params['verbose'],
                    meshid=("h%s" % h).replace('.', ''),
                    ntimesteps=ntimesteps,
                    nloops=ElasticLF4.loop_chain_length * num_unroll,
                    partitioning=part_mode,
                    tile_size=tile_size,
                    extra_halo=extra_halo,
                    explicit_mode=explicit_mode,
                    glb_maps=params['use_glb_maps'],
                    prefetch=params['use_prefetch'],
                    coloring=params['coloring'],
                    poly_order=poly_order,
                    domain=os.path.splitext(os.path.basename(mesh.name))[0],
                    function_spaces=[self.elastic.S, self.elastic.U])

        return u1, s1
Exemple #3
0
    def run(self, T, TS=0):
        """ Run the elastic wave simulation until t = T or ntimesteps = TS.
        :param float T: The finish time of the simulation.
        :param float TS: The maximum number of timesteps performed; ignored if = 0.
        :returns: The final solution fields for velocity and stress.
        """

        # Write out the initial condition.
        self.write(self.u1, self.s1, self.tofile)

        info("Generating inverse mass matrix")
        # Pre-assemble the inverse mass matrices, which should stay
        # constant throughout the simulation (assuming no mesh adaptivity).
        start = time()
        self.assemble_inverse_mass()
        end = time()
        info("DONE! (Elapsed: %f s)" % round(end - start, 3))
        op2.MPI.COMM_WORLD.barrier()
        info("Copying inverse mass matrix into a dat...")
        start = time()
        self.copy_massmatrix_into_dat()
        end = time()
        info("DONE! (Elapsed: %f s)" % round(end - start, 3))
        op2.MPI.COMM_WORLD.barrier()

        start = time()
        t = self.dt
        timestep = 0
        ntimesteps = sys.maxint if TS == 0 else TS

        while t <= T + 1e-12 and timestep < ntimesteps:
            if op2.MPI.COMM_WORLD.rank == 0 and timestep % self.output == 0:
                info("t = %f, (timestep = %d)" % (t, timestep))
            with loop_chain("main1",
                            tile_size=self.tiling_size,
                            num_unroll=self.tiling_uf,
                            mode=self.tiling_mode,
                            extra_halo=self.tiling_halo,
                            explicit=self.tiling_explicit,
                            use_glb_maps=self.tiling_glb_maps,
                            use_prefetch=self.tiling_prefetch,
                            coloring=self.tiling_coloring,
                            ignore_war=True,
                            log=self.tiling_log):
                # In case the source is time-dependent, update the time 't' here.
                if (self.source):
                    with timed_region('source term update'):
                        self.source_expression.t = t
                        self.source = self.source_expression

                # Solve for the velocity vector field.
                self.solve(self.rhs_uh1, self.velocity_mass_asdat, self.uh1)
                self.solve(self.rhs_stemp, self.stress_mass_asdat, self.stemp)
                self.solve(self.rhs_uh2, self.velocity_mass_asdat, self.uh2)
                self.solve(self.rhs_u1, self.velocity_mass_asdat, self.u1)

                # Solve for the stress tensor field.
                self.solve(self.rhs_sh1, self.stress_mass_asdat, self.sh1)
                self.solve(self.rhs_utemp, self.velocity_mass_asdat,
                           self.utemp)
                self.solve(self.rhs_sh2, self.stress_mass_asdat, self.sh2)
                self.solve(self.rhs_s1, self.stress_mass_asdat, self.s1)

            self.u0.assign(self.u1)
            self.s0.assign(self.s1)

            # Write out the new fields
            self.write(self.u1, self.s1, self.tofile
                       and timestep % self.output == 0)

            # Move onto next timestep
            t += self.dt
            timestep += 1

        # Write out the final state of the fields
        self.write(self.u1, self.s1, self.tofile)

        end = time()

        return start, end, timestep, self.u1, self.s1
Exemple #4
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    def __init__(self, mesh, family, degree, dimension, output=1, params=None):
        r""" Initialise a new elastic wave simulation.

        :param mesh: The underlying computational mesh of vertices and edges.
        :param str family: Specify whether CG or DG should be used.
        :param int degree: Use polynomial basis functions of this degree.
        :param int dimension: The spatial dimension of the problem (1, 2 or 3).
        :param int output: period, in timesteps, to write solution fields to a file.
        :param dict params: simulation and optimisation parameters
        :returns: None
        """
        self.degree = degree
        self.mesh = mesh
        self.dimension = dimension
        self.output = output

        self.tofile = params['tofile']

        self.S = TensorFunctionSpace(mesh, family, degree, name='S')
        self.U = VectorFunctionSpace(mesh, family, degree, name='U')
        # Assumes that the S and U function spaces are the same.
        self.S_tot_dofs = op2.MPI.COMM_WORLD.allreduce(self.S.dof_count,
                                                       op=mpi4py.MPI.SUM)
        self.U_tot_dofs = op2.MPI.COMM_WORLD.allreduce(self.U.dof_count,
                                                       op=mpi4py.MPI.SUM)
        info("Number of degrees of freedom (Velocity): %d" % self.U_tot_dofs)
        info("Number of degrees of freedom (Stress): %d" % self.S_tot_dofs)

        self.s = TrialFunction(self.S)
        self.v = TestFunction(self.S)
        self.u = TrialFunction(self.U)
        self.w = TestFunction(self.U)

        self.s0 = Function(self.S, name="StressOld")
        self.sh1 = Function(self.S, name="StressHalf1")
        self.stemp = Function(self.S, name="StressTemp")
        self.sh2 = Function(self.S, name="StressHalf2")
        self.s1 = Function(self.S, name="StressNew")

        self.u0 = Function(self.U, name="VelocityOld")
        self.uh1 = Function(self.U, name="VelocityHalf1")
        self.utemp = Function(self.U, name="VelocityTemp")
        self.uh2 = Function(self.U, name="VelocityHalf2")
        self.u1 = Function(self.U, name="VelocityNew")

        self.absorption_function = None
        self.source_function = None
        self.source_expression = None
        self._dt = None
        self._density = None
        self._mu = None
        self._l = None

        self.n = FacetNormal(self.mesh)
        self.I = Identity(self.dimension)

        # Tiling options
        self.tiling_size = params['tile_size']
        self.tiling_uf = params['num_unroll']
        self.tiling_mode = params['mode']
        self.tiling_halo = params['extra_halo']
        self.tiling_explicit = params['explicit_mode']
        self.tiling_explicit_id = params['explicit_mode_id']
        self.tiling_log = params['log']
        self.tiling_sdepth = params['s_depth']
        self.tiling_part = params['partitioning']
        self.tiling_coloring = params['coloring']
        self.tiling_glb_maps = params['use_glb_maps']
        self.tiling_prefetch = params['use_prefetch']

        # Mat-vec AST cache
        self.asts = {}

        if self.tofile:
            # File output streams
            platform = os.environ.get('NODENAME', 'unknown')
            tmpdir = os.environ['TMPDIR']
            base = os.path.join(tmpdir, 'output', platform,
                                'p%d' % self.degree, 'uf%d' % self.tiling_uf)
            if op2.MPI.COMM_WORLD.rank == 0:
                if not os.path.exists(base):
                    os.makedirs(base)
                sub_dirs = [
                    d for d in os.listdir(base)
                    if os.path.isdir(os.path.join(base, d))
                ]
                sub_dir = "%d_em%d_part%s_tile%s" % (
                    len(sub_dirs), self.tiling_explicit_id,
                    self.tiling_size if self.tiling_uf else 0,
                    self.tiling_part if self.tiling_uf else 'None')
                base = os.path.join(base, sub_dir)
                os.makedirs(base)
            op2.MPI.COMM_WORLD.barrier()
            base = op2.MPI.COMM_WORLD.bcast(base, root=0)
            self.u_stream = File(os.path.join(base, 'velocity.pvd'))
            self.s_stream = File(os.path.join(base, 'stress.pvd'))
Exemple #5
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        'explicit_mode': args.explicit_mode,
        'explicit_mode_id': args.explicit_mode,
        'use_glb_maps': args.glb_maps,
        'use_prefetch': args.prefetch,
        'log': args.log,
        'tofile': args.tofile,
        'verbose': args.verbose
    }

    # Set the kernel optimizaation level (default: O2)
    parameters['coffee']['optlevel'] = args.coffee_opt

    # Is it just a run to check correctness?
    if args.check:
        Lx, Ly, h, time_max, tolerance = 20, 20, 2.5, 0.01, 1e-10
        info("Checking correctness of original and tiled versions, with:")
        info("    (Lx, Ly, T, tolerance)=%s" % str(
            (Lx, Ly, time_max, tolerance)))
        info("    %s" % params)
        # Run the tiled variant
        u1, s1 = ExplosiveSourceLF4().explosive_source_lf4(
            time_max, Lx, Ly, h, sys.maxint, params)
        # Run the original code
        original = {
            'num_unroll': 0,
            'tile_size': 0,
            'mode': None,
            'partitioning': 'chunk',
            'extra_halo': 0
        }
        u1_orig, s1_orig = ExplosiveSourceLF4().explosive_source_lf4(