Esempio n. 1
0
    def test_term_arithmetics(self):
        from sfepy.fem import FieldVariable, Integral
        from sfepy.terms.terms import Term

        integral = Integral('i', order=3)
        integral_s = Integral('i', kind='s', order=3)

        u = FieldVariable('u', 'parameter', self.field, self.dim,
                          primary_var_name='(set-to-None)')

        t1 = Term.new('d_volume(u)', integral, self.omega, u=u)
        t2 = Term.new('d_surface(u)', integral_s, self.gamma1, u=u)

        expr = 2.2j * (t1 * 5.5 - 3j * t2) * 0.25

        ok = len(expr) == 2
        if not ok:
            self.report('wrong expression length!')

        _ok = nm.allclose(expr[0].sign, 3.025j, rtol=1e-15, atol=0)
        if not _ok:
            self.report('wrong sign of the first term!')
        ok = ok and _ok

        _ok = nm.allclose(expr[1].sign, 1.65, rtol=1e-15, atol=0)
        if not _ok:
            self.report('wrong sign of the second term!')
        ok = ok and _ok

        return ok
Esempio n. 2
0
    def test_normals(self):
        """
        Check orientations of surface normals on the reference elements.
        """
        import sfepy
        from sfepy.fem import Mesh, Domain, Integral
        from sfepy.fem.poly_spaces import PolySpace
        from sfepy.fem.mappings import SurfaceMapping
        from sfepy.linalg import normalize_vectors

        ok = True

        for geom in ['2_3', '2_4', '3_4', '3_8']:
            mesh = Mesh.from_file('meshes/elements/%s_1.mesh' % geom,
                                  prefix_dir=sfepy.data_dir)
            domain = Domain('domain', mesh)
            surface = domain.create_region('Surface', 'vertices of surface',
                                           'facet')
            domain.create_surface_group(surface)

            sd = domain.surface_groups[0][surface.name]

            coors = domain.get_mesh_coors()
            gel = domain.geom_els[geom].surface_facet
            ps = PolySpace.any_from_args('aux', gel, 1)

            mapping = SurfaceMapping(coors, sd.get_connectivity(), ps)

            integral = Integral('i', order=1)
            vals, weights = integral.get_qp(gel.name)

            # Evaluate just in the first quadrature point...
            geo = mapping.get_mapping(vals[:1], weights[:1])

            expected = expected_normals[geom].copy()
            normalize_vectors(expected)

            _ok = nm.allclose(expected,
                              geo.normal[:, 0, :, 0],
                              rtol=0.0,
                              atol=1e-14)
            self.report('%s: %s' % (geom, _ok))

            if not _ok:
                self.report('expected:')
                self.report(expected)
                self.report('actual:')
                self.report(geo.normal[:, 0, :, 0])

            ok = ok and _ok

        return ok
Esempio n. 3
0
def _get_qp(geometry, order):
    from sfepy.fem import Integral
    from sfepy.fem.geometry_element import GeometryElement

    aux = Integral('aux', order=order)
    coors, weights = aux.get_qp(geometry)
    true_order = aux.qps[geometry].order

    output('geometry:', geometry, 'order:', order, 'num. points:',
           coors.shape[0], 'true_order:', true_order)
    output('min. weight:', weights.min())
    output('max. weight:', weights.max())

    return GeometryElement(geometry), coors, weights
Esempio n. 4
0
def _get_qp(geometry, order):
    from sfepy.fem import Integral
    from sfepy.fem.geometry_element import GeometryElement

    aux = Integral('aux', order=order)
    coors, weights = aux.get_qp(geometry)
    true_order = aux.qps[geometry].order

    output('geometry:', geometry, 'order:', order, 'num. points:',
           coors.shape[0], 'true_order:', true_order)
    output('min. weight:', weights.min())
    output('max. weight:', weights.max())

    return GeometryElement(geometry), coors, weights
Esempio n. 5
0
    def test_normals(self):
        """
        Check orientations of surface normals on the reference elements.
        """
        import sfepy
        from sfepy.fem import Mesh, Domain, Integral
        from sfepy.fem.poly_spaces import PolySpace
        from sfepy.fem.mappings import SurfaceMapping
        from sfepy.linalg import normalize_vectors

        ok = True

        for geom in ['2_3', '2_4', '3_4', '3_8']:
            mesh = Mesh.from_file('meshes/elements/%s_1.mesh' % geom,
                                  prefix_dir=sfepy.data_dir)
            domain = Domain('domain', mesh)
            surface = domain.create_region('Surface', 'nodes of surface')
            domain.create_surface_group(surface)

            sd = domain.surface_groups[0][surface.name]

            coors = domain.get_mesh_coors()
            gel = domain.geom_els[geom].surface_facet
            ps = PolySpace.any_from_args('aux', gel, 1)

            mapping = SurfaceMapping(coors, sd.get_connectivity(), ps)

            integral = Integral('i', order=1)
            vals, weights = integral.get_qp(gel.name)

            # Evaluate just in the first quadrature point...
            geo = mapping.get_mapping(vals[:1], weights[:1])

            expected = expected_normals[geom].copy()
            normalize_vectors(expected)

            _ok = nm.allclose(expected, geo.normal[:, 0, :, 0],
                              rtol=0.0, atol=1e-14)
            self.report('%s: %s' % (geom, _ok))

            if not _ok:
                self.report('expected:')
                self.report(expected)
                self.report('actual:')
                self.report(geo.normal[:, 0, :, 0])

            ok = ok and _ok

        return ok
Esempio n. 6
0
    def test_term_evaluation(self):
        from sfepy.fem import Integral, FieldVariable
        from sfepy.terms.terms import Term

        integral = Integral('i', order=3)

        u = FieldVariable('u', 'parameter', self.field, self.dim,
                          primary_var_name='(set-to-None)')

        term = Term.new('d_volume(u)', integral, self.omega, u=u)
        term *= 10.0

        term.setup()

        vol = term.evaluate()

        self.report('volume: %.8f == 2000.0' % vol)
        ok = nm.allclose(vol, 2000.0, rtol=1e-15, atol=0)

        ## vec = t1.evaluate() # Returns vector.
        ## vec = t1.evaluate(u=u_vec) # Returns the same vector.
        ## mtx = t1.evaluate(diff_var='u') # Returns matrix.
        ## val = t1.evaluate(v=u_vec, u=u_vec) # Forbidden - virtual variable
        ##                                     # cannot have value.

        return ok
Esempio n. 7
0
    def test_solving(self):
        from sfepy.base.base import IndexedStruct
        from sfepy.fem \
             import FieldVariable, Material, ProblemDefinition, \
                    Function, Equation, Equations, Integral
        from sfepy.fem.conditions import Conditions, EssentialBC
        from sfepy.terms import Term
        from sfepy.solvers.ls import ScipyDirect
        from sfepy.solvers.nls import Newton

        u = FieldVariable('u', 'unknown', self.field, self.dim)
        v = FieldVariable('v', 'test', self.field, self.dim,
                          primary_var_name='u')

        m = Material('m', lam=1.0, mu=1.0)
        f = Material('f', val=[[0.02], [0.01]])

        bc_fun = Function('fix_u_fun', fix_u_fun,
                          extra_args={'extra_arg' : 'hello'})

        fix_u = EssentialBC('fix_u', self.gamma1, {'u.all' : bc_fun})
        shift_u = EssentialBC('shift_u', self.gamma2, {'u.0' : 0.1})

        integral = Integral('i', order=3)

        t1 = Term.new('dw_lin_elastic_iso(m.lam, m.mu, v, u)',
                      integral, self.omega, m=m, v=v, u=u)

        t2 = Term.new('dw_volume_lvf(f.val, v)', integral, self.omega, f=f, v=v)

        eq = Equation('balance', t1 + t2)
        eqs = Equations([eq])

        ls = ScipyDirect({})

        nls_status = IndexedStruct()
        nls = Newton({}, lin_solver=ls, status=nls_status)

        pb = ProblemDefinition('elasticity', equations=eqs, nls=nls, ls=ls)
        ## pb.save_regions_as_groups('regions')

        pb.time_update(ebcs=Conditions([fix_u, shift_u]))

        state = pb.solve()

        name = op.join(self.options.out_dir, 'test_high_level_solving.vtk')
        pb.save_state(name, state)

        ok = nls_status.condition == 0
        if not ok:
            self.report('solver did not converge!')

        _ok = state.has_ebc()
        if not _ok:
            self.report('EBCs violated!')

        ok = ok and _ok

        return ok
Esempio n. 8
0
def _integrate(var, val_qp):
    from sfepy.fem import Integral
    from sfepy.fem.mappings import get_jacobian

    integral = Integral('i', 2)
    det = get_jacobian(var.field, integral)
    val = (val_qp * det).sum(axis=1) / det.sum(axis=1)

    return val
Esempio n. 9
0
def make_h1_projection_data(target, eval_data):
    """
    Project scalar data given by a material-like `eval_data()` function to a
    scalar `target` field variable using the :math:`H^1` dot product.
    """
    order = target.field.approx_order * 2
    integral = Integral('i', order=order)

    un = target.name
    v = FieldVariable('v', 'test', target.field, 1, primary_var_name=un)
    lhs1 = Term.new('dw_volume_dot(v, %s)' % un,
                    integral,
                    target.field.region,
                    v=v,
                    **{un: target})
    lhs2 = Term.new('dw_laplace(v, %s)' % un,
                    integral,
                    target.field.region,
                    v=v,
                    **{un: target})

    def _eval_data(ts, coors, mode, **kwargs):
        if mode == 'qp':
            val = eval_data(ts, coors, mode, 'val', **kwargs)
            gval = eval_data(ts, coors, mode, 'grad', **kwargs)
            return {'val': val, 'gval': gval}

    m = Material('m', function=_eval_data)
    rhs1 = Term.new('dw_volume_lvf(m.val, v)',
                    integral,
                    target.field.region,
                    m=m,
                    v=v)
    rhs2 = Term.new('dw_diffusion_r(m.gval, v)',
                    integral,
                    target.field.region,
                    m=m,
                    v=v)

    eq = Equation('projection', lhs1 + lhs2 - rhs1 - rhs2)
    eqs = Equations([eq])

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    pb = ProblemDefinition('aux', equations=eqs, nls=nls, ls=ls)

    pb.time_update()

    # This sets the target variable with the projection solution.
    pb.solve()

    if nls_status.condition != 0:
        output('H1 projection: solver did not converge!')
Esempio n. 10
0
    def from_conf(conf, options):
        from sfepy.fem import Mesh, Domain, Integral

        domains = []
        for filename in filename_meshes:
            mesh = Mesh.from_file(filename)
            domain = Domain('domain_%s' % mesh.name.replace(data_dir, ''),
                            mesh)
            domain.create_region('Omega', 'all')
            domain.create_region('Gamma', 'nodes of surface')

            domains.append(domain)

        integrals = {'Omega' : Integral('iv', kind='v', order=3),
                     'Gamma' : Integral('is', kind='s', order=3)}

        test = Test(domains=domains, integrals=integrals,
                    conf=conf, options=options)
        return test
Esempio n. 11
0
    def test_invariance_qp(self):
        from sfepy import data_dir
        from sfepy.fem import (Mesh, Domain, H1NodalVolumeField, Variables,
                               Integral)
        from sfepy.terms import Term
        from sfepy.fem.mappings import get_physical_qps

        mesh = Mesh('source mesh', data_dir + '/meshes/3d/block.mesh')

        bbox = mesh.get_bounding_box()
        dd = bbox[1, :] - bbox[0, :]
        data = nm.sin(4.0 * nm.pi * mesh.coors[:,0:1] / dd[0]) \
               * nm.cos(4.0 * nm.pi * mesh.coors[:,1:2] / dd[1])

        variables = {
            'u': ('unknown field', 'scalar_tp', 0),
            'v': ('test field', 'scalar_tp', 'u'),
        }

        domain = Domain('domain', mesh)
        omega = domain.create_region('Omega', 'all')
        field = H1NodalVolumeField('scalar_tp',
                                   nm.float64,
                                   1,
                                   omega,
                                   approx_order=1)
        ff = {field.name: field}

        vv = Variables.from_conf(transform_variables(variables), ff)
        u = vv['u']
        u.set_from_mesh_vertices(data)

        integral = Integral('i', order=2)
        term = Term.new('ev_volume_integrate(u)', integral, omega, u=u)
        term.setup()
        val1, _ = term.evaluate(mode='qp')
        val1 = val1.ravel()

        qps = get_physical_qps(omega, integral)
        coors = qps.get_merged_values()

        val2 = u.evaluate_at(coors).ravel()

        self.report('max. difference:', nm.abs(val1 - val2).max())
        ok = nm.allclose(val1, val2, rtol=0.0, atol=1e-12)
        self.report('invariance in qp: %s' % ok)

        return ok
Esempio n. 12
0
    def from_conf(conf, options):
        from sfepy.fem import Mesh, Domain, Integral

        domains = []
        for filename in filename_meshes:
            mesh = Mesh.from_file(filename)
            domain = Domain('domain_%s' % mesh.name.replace(data_dir, ''),
                            mesh)
            domain.create_region('Omega', 'all')
            domain.create_region('Gamma', 'vertices of surface', 'facet')

            domains.append(domain)

        integral = Integral('i', order=3)

        test = Test(domains=domains,
                    integral=integral,
                    conf=conf,
                    options=options)
        return test
Esempio n. 13
0
def create_mass_matrix(field):
    """
    Create scalar mass matrix corresponding to the given field.

    Returns
    -------
    mtx : csr_matrix
        The mass matrix in CSR format.
    """
    u = FieldVariable('u', 'unknown', field, 1)
    v = FieldVariable('v', 'test', field, 1, primary_var_name='u')

    integral = Integral('i', order=field.approx_order * 2)
    term = Term.new('dw_volume_dot(v, u)', integral, field.region, v=v, u=u)
    eq = Equation('aux', term)
    eqs = Equations([eq])
    eqs.time_update(None)

    dummy = eqs.create_state_vector()

    mtx = eqs.create_matrix_graph()
    mtx = eqs.eval_tangent_matrices(dummy, mtx)

    return mtx
Esempio n. 14
0
def main():
    parser = OptionParser(usage=usage, version="%prog")
    parser.add_option(
        "-b", "--basis", metavar="name", action="store", dest="basis", default="lagrange", help=help["basis"]
    )
    parser.add_option(
        "-n",
        "--max-order",
        metavar="order",
        type=int,
        action="store",
        dest="max_order",
        default=10,
        help=help["max_order"],
    )
    parser.add_option(
        "-m",
        "--matrix",
        metavar="type",
        action="store",
        dest="matrix_type",
        default="laplace",
        help=help["matrix_type"],
    )
    parser.add_option(
        "-g", "--geometry", metavar="name", action="store", dest="geometry", default="2_4", help=help["geometry"]
    )
    options, args = parser.parse_args()

    dim, n_ep = int(options.geometry[0]), int(options.geometry[2])
    output("reference element geometry:")
    output("  dimension: %d, vertices: %d" % (dim, n_ep))

    n_c = {"laplace": 1, "elasticity": dim}[options.matrix_type]

    output("matrix type:", options.matrix_type)
    output("number of variable components:", n_c)

    output("polynomial space:", options.basis)

    output("max. order:", options.max_order)

    mesh = Mesh.from_file(data_dir + "/meshes/elements/%s_1.mesh" % options.geometry)
    domain = Domain("domain", mesh)
    omega = domain.create_region("Omega", "all")

    orders = nm.arange(1, options.max_order + 1, dtype=nm.int)
    conds = []

    order_fix = 0 if options.geometry in ["2_4", "3_8"] else 1

    for order in orders:
        output("order:", order, "...")

        field = Field.from_args(
            "fu", nm.float64, n_c, omega, approx_order=order, space="H1", poly_space_base=options.basis
        )

        to = field.approx_order
        quad_order = 2 * (max(to - order_fix, 0))
        output("quadrature order:", quad_order)

        integral = Integral("i", order=quad_order)
        qp, _ = integral.get_qp(options.geometry)
        output("number of quadrature points:", qp.shape[0])

        u = FieldVariable("u", "unknown", field, n_c)
        v = FieldVariable("v", "test", field, n_c, primary_var_name="u")

        m = Material("m", lam=1.0, mu=1.0)

        if options.matrix_type == "laplace":
            term = Term.new("dw_laplace(m.mu, v, u)", integral, omega, m=m, v=v, u=u)
            n_zero = 1

        else:
            assert_(options.matrix_type == "elasticity")
            term = Term.new("dw_lin_elastic_iso(m.lam, m.mu, v, u)", integral, omega, m=m, v=v, u=u)
            n_zero = (dim + 1) * dim / 2

        term.setup()

        output("assembling...")
        tt = time.clock()
        mtx, iels = term.evaluate(mode="weak", diff_var="u")
        output("...done in %.2f s" % (time.clock() - tt))
        mtx = mtx[0][0, 0]

        try:
            assert_(nm.max(nm.abs(mtx - mtx.T)) < 1e-10)

        except:
            from sfepy.base.base import debug

            debug()

        output("matrix shape:", mtx.shape)

        eigs = eig(mtx, method="eig.sgscipy", eigenvectors=False)
        eigs.sort()

        # Zero 'true' zeros.
        eigs[:n_zero] = 0.0

        ii = nm.where(eigs < 0.0)[0]
        if len(ii):
            output("matrix is not positive semi-definite!")

        ii = nm.where(eigs[n_zero:] < 1e-12)[0]
        if len(ii):
            output("matrix has more than %d zero eigenvalues!" % n_zero)

        output("smallest eigs:\n", eigs[:10])

        ii = nm.where(eigs > 0.0)[0]
        emin, emax = eigs[ii[[0, -1]]]

        output("min:", emin, "max:", emax)

        cond = emax / emin
        conds.append(cond)

        output("condition number:", cond)

        output("...done")

    plt.figure(1)
    plt.semilogy(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel("polynomial order")
    plt.ylabel("condition number")
    plt.grid()

    plt.figure(2)
    plt.loglog(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel("polynomial order")
    plt.ylabel("condition number")
    plt.grid()

    plt.show()
Esempio n. 15
0
def main():
    from sfepy import data_dir

    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('-s',
                      '--show',
                      action="store_true",
                      dest='show',
                      default=False,
                      help=help['show'])
    options, args = parser.parse_args()

    mesh = Mesh.from_file(data_dir + '/meshes/2d/rectangle_tri.mesh')
    domain = Domain('domain', mesh)

    min_x, max_x = domain.get_mesh_bounding_box()[:, 0]
    eps = 1e-8 * (max_x - min_x)
    omega = domain.create_region('Omega', 'all')
    gamma1 = domain.create_region('Gamma1',
                                  'nodes in x < %.10f' % (min_x + eps))
    gamma2 = domain.create_region('Gamma2',
                                  'nodes in x > %.10f' % (max_x - eps))

    field = H1NodalVolumeField('fu',
                               nm.float64,
                               'vector',
                               omega,
                               approx_order=2)

    u = FieldVariable('u', 'unknown', field, mesh.dim)
    v = FieldVariable('v', 'test', field, mesh.dim, primary_var_name='u')

    m = Material('m', lam=1.0, mu=1.0)
    f = Material('f', val=[[0.02], [0.01]])

    integral = Integral('i', order=3)

    t1 = Term.new('dw_lin_elastic_iso(m.lam, m.mu, v, u)',
                  integral,
                  omega,
                  m=m,
                  v=v,
                  u=u)
    t2 = Term.new('dw_volume_lvf(f.val, v)', integral, omega, f=f, v=v)
    eq = Equation('balance', t1 + t2)
    eqs = Equations([eq])

    fix_u = EssentialBC('fix_u', gamma1, {'u.all': 0.0})

    bc_fun = Function('shift_u_fun', shift_u_fun, extra_args={'shift': 0.01})
    shift_u = EssentialBC('shift_u', gamma2, {'u.0': bc_fun})

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    pb = ProblemDefinition('elasticity', equations=eqs, nls=nls, ls=ls)
    pb.save_regions_as_groups('regions')

    pb.time_update(ebcs=Conditions([fix_u, shift_u]))

    vec = pb.solve()
    print nls_status

    pb.save_state('linear_elasticity.vtk', vec)

    if options.show:
        view = Viewer('linear_elasticity.vtk')
        view(vector_mode='warp_norm',
             rel_scaling=2,
             is_scalar_bar=True,
             is_wireframe=True)
Esempio n. 16
0
def _gen_common_data(order, gels, report):
    import sfepy
    from sfepy.base.base import Struct
    from sfepy.linalg import combine
    from sfepy.fem import Mesh, Domain, Field, FieldVariable, Integral
    from sfepy.fem.global_interp import get_ref_coors

    integral = Integral('i', order=order)

    for geom, poly_space_base in combine([['2_4', '3_8'],
                                          ['lagrange', 'lobatto']]):
        report('geometry: %s, base: %s' % (geom, poly_space_base))

        mesh0 = Mesh.from_file('meshes/elements/%s_2.mesh' % geom,
                               prefix_dir=sfepy.data_dir)
        gel = gels[geom]

        perms = gel.get_conn_permutations()

        qps, qp_weights = integral.get_qp(gel.surface_facet.name)
        zz = nm.zeros_like(qps[:, :1])
        qps = nm.hstack(([qps] + [zz]))

        rot = rots[geom]
        if rot is not None:
            pass

        shift = shifts[geom]
        rcoors = nm.ascontiguousarray(qps
                                      + shift[:1, :] - shift[1:, :])
        ccoors = nm.ascontiguousarray(qps
                                      + shift[:1, :] + shift[1:, :])

        for ir, pr in enumerate(perms):
            for ic, pc in enumerate(perms):
                report('ir: %d, ic: %d' % (ir, ic))

                mesh = mesh0.copy()
                conn = mesh.conns[0]
                conn[0, :] = conn[0, pr]
                conn[1, :] = conn[1, pc]

                cache = Struct(mesh=mesh)

                domain = Domain('domain', mesh)
                omega = domain.create_region('Omega', 'all')
                region = domain.create_region('Facet', rsels[geom])
                field = Field.from_args('f', nm.float64, shape=1,
                                        region=omega, approx_order=order,
                                        poly_space_base=poly_space_base)
                var = FieldVariable('u', 'unknown', field, 1)
                report('# dofs: %d' % var.n_dof)

                vec = nm.empty(var.n_dof, dtype=var.dtype)

                ap = field.aps[0]
                ps = ap.interp.poly_spaces['v']

                dofs = field.get_dofs_in_region_group(region, 0,
                                                      merge=False)
                edofs, fdofs = nm.unique(dofs[1]), nm.unique(dofs[2])

                rrc, rcells, rstatus = get_ref_coors(field, rcoors,
                                                     cache=cache)
                crc, ccells, cstatus = get_ref_coors(field, ccoors,
                                                     cache=cache)

                yield (geom, poly_space_base, qp_weights, mesh, ir, ic,
                       ap, ps, rrc, crc, vec, edofs, fdofs)
Esempio n. 17
0
def main():
    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('-b',
                      '--basis',
                      metavar='name',
                      action='store',
                      dest='basis',
                      default='lagrange',
                      help=help['basis'])
    parser.add_option('-n',
                      '--max-order',
                      metavar='order',
                      type=int,
                      action='store',
                      dest='max_order',
                      default=10,
                      help=help['max_order'])
    parser.add_option('-m',
                      '--matrix',
                      metavar='type',
                      action='store',
                      dest='matrix_type',
                      default='laplace',
                      help=help['matrix_type'])
    parser.add_option('-g',
                      '--geometry',
                      metavar='name',
                      action='store',
                      dest='geometry',
                      default='2_4',
                      help=help['geometry'])
    options, args = parser.parse_args()

    dim, n_ep = int(options.geometry[0]), int(options.geometry[2])
    output('reference element geometry:')
    output('  dimension: %d, vertices: %d' % (dim, n_ep))

    n_c = {'laplace': 1, 'elasticity': dim}[options.matrix_type]

    output('matrix type:', options.matrix_type)
    output('number of variable components:', n_c)

    output('polynomial space:', options.basis)

    output('max. order:', options.max_order)

    mesh = Mesh.from_file(data_dir +
                          '/meshes/elements/%s_1.mesh' % options.geometry)
    domain = Domain('domain', mesh)
    omega = domain.create_region('Omega', 'all')

    orders = nm.arange(1, options.max_order + 1, dtype=nm.int)
    conds = []

    order_fix = 0 if options.geometry in ['2_4', '3_8'] else 1

    for order in orders:
        output('order:', order, '...')

        field = Field.from_args('fu',
                                nm.float64,
                                n_c,
                                omega,
                                approx_order=order,
                                space='H1',
                                poly_space_base=options.basis)

        to = field.approx_order
        quad_order = 2 * (max(to - order_fix, 0))
        output('quadrature order:', quad_order)

        integral = Integral('i', order=quad_order)
        qp, _ = integral.get_qp(options.geometry)
        output('number of quadrature points:', qp.shape[0])

        u = FieldVariable('u', 'unknown', field, n_c)
        v = FieldVariable('v', 'test', field, n_c, primary_var_name='u')

        m = Material('m', lam=1.0, mu=1.0)

        if options.matrix_type == 'laplace':
            term = Term.new('dw_laplace(m.mu, v, u)',
                            integral,
                            omega,
                            m=m,
                            v=v,
                            u=u)
            n_zero = 1

        else:
            assert_(options.matrix_type == 'elasticity')
            term = Term.new('dw_lin_elastic_iso(m.lam, m.mu, v, u)',
                            integral,
                            omega,
                            m=m,
                            v=v,
                            u=u)
            n_zero = (dim + 1) * dim / 2

        term.setup()

        output('assembling...')
        tt = time.clock()
        mtx, iels = term.evaluate(mode='weak', diff_var='u')
        output('...done in %.2f s' % (time.clock() - tt))
        mtx = mtx[0][0, 0]

        try:
            assert_(nm.max(nm.abs(mtx - mtx.T)) < 1e-10)

        except:
            from sfepy.base.base import debug
            debug()

        output('matrix shape:', mtx.shape)

        eigs = eig(mtx, method='eig.sgscipy', eigenvectors=False)
        eigs.sort()

        # Zero 'true' zeros.
        eigs[:n_zero] = 0.0

        ii = nm.where(eigs < 0.0)[0]
        if len(ii):
            output('matrix is not positive semi-definite!')

        ii = nm.where(eigs[n_zero:] < 1e-12)[0]
        if len(ii):
            output('matrix has more than %d zero eigenvalues!' % n_zero)

        output('smallest eigs:\n', eigs[:10])

        ii = nm.where(eigs > 0.0)[0]
        emin, emax = eigs[ii[[0, -1]]]

        output('min:', emin, 'max:', emax)

        cond = emax / emin
        conds.append(cond)

        output('condition number:', cond)

        output('...done')

    plt.figure(1)
    plt.semilogy(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel('polynomial order')
    plt.ylabel('condition number')
    plt.grid()

    plt.figure(2)
    plt.loglog(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel('polynomial order')
    plt.ylabel('condition number')
    plt.grid()

    plt.show()
Esempio n. 18
0
File: fea.py Progetto: sdurve/sfepy
    def describe_geometry(self,
                          field,
                          gtype,
                          region,
                          integral=None,
                          return_mapping=False):
        """
        Compute jacobians, element volumes and base function derivatives
        for Volume-type geometries (volume mappings), and jacobians,
        normals and base function derivatives for Surface-type
        geometries (surface mappings).

        Notes
        -----
        - volume mappings can be defined on a part of an element group,
          although the field has to be defined always on the whole group.
        - surface mappings are defined on the surface region
        - surface mappings require field order to be > 0
        """
        domain = field.domain
        group = domain.groups[self.ig]
        coors = domain.get_mesh_coors(actual=True)

        if gtype == 'volume':
            if integral is None:
                from sfepy.fem import Integral
                integral = Integral('i_tmp', 'v', 1)

            qp = self.get_qp('v', integral)

            iels = region.cells[self.ig]

            geo_ps = self.interp.get_geom_poly_space('v')
            ps = self.interp.poly_spaces['v']
            bf = self.get_base('v', 0, integral, iels=iels)

            conn = nm.take(group.conn, iels, axis=0)
            mapping = VolumeMapping(coors, conn, poly_space=geo_ps)
            vg = mapping.get_mapping(qp.vals,
                                     qp.weights,
                                     poly_space=ps,
                                     ori=self.ori)

            out = vg

        elif (gtype == 'surface') or (gtype == 'surface_extra'):
            assert_(field.approx_order > 0)

            if self.ori is not None:
                msg = 'surface integrals do not work yet with the' \
                      ' hierarchical basis!'
                raise ValueError(msg)

            sd = domain.surface_groups[self.ig][region.name]
            esd = self.surface_data[region.name]

            qp = self.get_qp(sd.face_type, integral)

            geo_ps = self.interp.get_geom_poly_space(sd.face_type)
            ps = self.interp.poly_spaces[esd.face_type]
            bf = self.get_base(esd.face_type, 0, integral)

            conn = sd.get_connectivity()

            mapping = SurfaceMapping(coors, conn, poly_space=geo_ps)
            sg = mapping.get_mapping(qp.vals, qp.weights, poly_space=ps)

            if gtype == 'surface_extra':
                sg.alloc_extra_data(self.get_v_data_shape()[2])

                self.create_bqp(region.name, integral)
                qp = self.qp_coors[(integral.name, esd.bkey)]

                v_geo_ps = self.interp.get_geom_poly_space('v')
                bf_bg = v_geo_ps.eval_base(qp.vals, diff=True)
                ebf_bg = self.get_base(esd.bkey, 1, integral)

                sg.evaluate_bfbgm(bf_bg, ebf_bg, coors, sd.fis, group.conn)

            out = sg

        elif gtype == 'point':
            out = mapping = None

        else:
            raise ValueError('unknown geometry type: %s' % gtype)

        if out is not None:
            # Store the integral used.
            out.integral = integral
            out.qp = qp
            out.ps = ps
            # Update base.
            out.bf[:] = bf

        if return_mapping:
            out = (out, mapping)

        return out
Esempio n. 19
0
def _gen_common_data(orders, gels, report):
    import sfepy
    from sfepy.base.base import Struct
    from sfepy.linalg import combine
    from sfepy.fem import Mesh, Domain, Field, FieldVariable, Integral
    from sfepy.fem.global_interp import get_ref_coors

    bases = ([ii for ii in combine([['2_4', '3_8'],
                                    ['lagrange', 'lobatto']])]
             + [ii for ii in combine([['2_3', '3_4'],
                                      ['lagrange']])])
    for geom, poly_space_base in bases:
        report('geometry: %s, base: %s' % (geom, poly_space_base))

        order = orders[geom]
        integral = Integral('i', order=order)

        aux = '' if geom in ['2_4', '3_8'] else 'z'
        mesh0 = Mesh.from_file('meshes/elements/%s_2%s.mesh' % (geom, aux),
                               prefix_dir=sfepy.data_dir)
        gel = gels[geom]

        perms = gel.get_conn_permutations()

        qps, qp_weights = integral.get_qp(gel.surface_facet.name)
        zz = nm.zeros_like(qps[:, :1])
        qps = nm.hstack(([qps] + [zz]))

        shift = shifts[geom]
        rcoors = nm.ascontiguousarray(qps
                                      + shift[:1, :] - shift[1:, :])
        ccoors = nm.ascontiguousarray(qps
                                      + shift[:1, :] + shift[1:, :])

        for ir, pr in enumerate(perms):
            for ic, pc in enumerate(perms):
                report('ir: %d, ic: %d' % (ir, ic))
                report('pr: %s, pc: %s' % (pr, pc))

                mesh = mesh0.copy()
                conn = mesh.conns[0]
                conn[0, :] = conn[0, pr]
                conn[1, :] = conn[1, pc]

                cache = Struct(mesh=mesh)

                domain = Domain('domain', mesh)
                omega = domain.create_region('Omega', 'all')
                region = domain.create_region('Facet', rsels[geom], 'facet')
                field = Field.from_args('f', nm.float64, shape=1,
                                        region=omega, approx_order=order,
                                        poly_space_base=poly_space_base)
                var = FieldVariable('u', 'unknown', field, 1)
                report('# dofs: %d' % var.n_dof)

                vec = nm.empty(var.n_dof, dtype=var.dtype)

                ap = field.aps[0]
                ps = ap.interp.poly_spaces['v']

                dofs = field.get_dofs_in_region_group(region, 0,
                                                      merge=False)
                edofs, fdofs = nm.unique(dofs[1]), nm.unique(dofs[2])

                rrc, rcells, rstatus = get_ref_coors(field, rcoors,
                                                     cache=cache)
                crc, ccells, cstatus = get_ref_coors(field, ccoors,
                                                     cache=cache)
                assert_((rstatus == 0).all() and (cstatus == 0).all())

                yield (geom, poly_space_base, qp_weights, mesh, ir, ic,
                       ap, ps, rrc, rcells[0, 1], crc, ccells[0, 1],
                       vec, edofs, fdofs)
Esempio n. 20
0
def eval_in_els_and_qp(expression, ig, iels, coors,
                       fields, materials, variables,
                       functions=None, mode='eval', term_mode=None,
                       extra_args=None, verbose=True, kwargs=None):
    """
    Evaluate an expression in given elements and points.

    Parameters
    ----------
    expression : str
        The expression to evaluate.
    fields : dict
        The dictionary of fields used in `variables`.
    materials : Materials instance
        The materials used in the expression.
    variables : Variables instance
        The variables used in the expression.
    functions : Functions instance, optional
        The user functions for materials etc.
    mode : one of 'eval', 'el_avg', 'qp'
        The evaluation mode - 'qp' requests the values in quadrature points,
        'el_avg' element averages and 'eval' means integration over
        each term region.
    term_mode : str
        The term call mode - some terms support different call modes
        and depending on the call mode different values are
        returned.
    extra_args : dict, optional
        Extra arguments to be passed to terms in the expression.
    verbose : bool
        If False, reduce verbosity.
    kwargs : dict, optional
        The variables (dictionary of (variable name) : (Variable
        instance)) to be used in the expression.

    Returns
    -------
    out : array
        The result of the evaluation.
    """
    weights = nm.ones_like(coors[:, 0])
    integral = Integral('ie', coors=coors, weights=weights)

    domain = fields.values()[0].domain

    region = Region('Elements', 'given elements', domain, '')
    region.cells = iels + domain.mesh.el_offsets[ig]
    region.update_shape()
    domain.regions.append(region)

    for field in fields.itervalues():
        field.clear_mappings(clear_all=True)
        for ap in field.aps.itervalues():
            ap.clear_qp_base()

    aux = create_evaluable(expression, fields, materials,
                           variables.itervalues(), Integrals([integral]),
                           functions=functions,
                           mode=mode, extra_args=extra_args, verbose=verbose,
                           kwargs=kwargs)
    equations, variables = aux

    out = eval_equations(equations, variables,
                         preserve_caches=False,
                         mode=mode, term_mode=term_mode)
    domain.regions.pop()

    return out
Esempio n. 21
0
def main():
    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('-b', '--basis', metavar='name',
                      action='store', dest='basis',
                      default='lagrange', help=help['basis'])
    parser.add_option('-n', '--max-order', metavar='order', type=int,
                      action='store', dest='max_order',
                      default=10, help=help['max_order'])
    parser.add_option('-m', '--matrix', metavar='type',
                      action='store', dest='matrix_type',
                      default='laplace', help=help['matrix_type'])
    parser.add_option('-g', '--geometry', metavar='name',
                      action='store', dest='geometry',
                      default='2_4', help=help['geometry'])
    options, args = parser.parse_args()

    dim, n_ep = int(options.geometry[0]), int(options.geometry[2])
    output('reference element geometry:')
    output('  dimension: %d, vertices: %d' % (dim, n_ep))

    n_c = {'laplace' : 1, 'elasticity' : dim}[options.matrix_type]

    output('matrix type:', options.matrix_type)
    output('number of variable components:',  n_c)

    output('polynomial space:', options.basis)

    output('max. order:', options.max_order)

    mesh = Mesh.from_file(data_dir + '/meshes/elements/%s_1.mesh'
                          % options.geometry)
    domain = Domain('domain', mesh)
    omega = domain.create_region('Omega', 'all')

    orders = nm.arange(1, options.max_order + 1, dtype=nm.int)
    conds = []

    order_fix = 0 if  options.geometry in ['2_4', '3_8'] else 1

    for order in orders:
        output('order:', order, '...')

        field = Field.from_args('fu', nm.float64, n_c, omega,
                                approx_order=order,
                                space='H1', poly_space_base=options.basis)

        to = field.approx_order
        quad_order = 2 * (max(to - order_fix, 0))
        output('quadrature order:', quad_order)

        integral = Integral('i', order=quad_order)
        qp, _ = integral.get_qp(options.geometry)
        output('number of quadrature points:', qp.shape[0])

        u = FieldVariable('u', 'unknown', field)
        v = FieldVariable('v', 'test', field, primary_var_name='u')

        m = Material('m', lam=1.0, mu=1.0)

        if options.matrix_type == 'laplace':
            term = Term.new('dw_laplace(m.mu, v, u)',
                            integral, omega, m=m, v=v, u=u)
            n_zero = 1

        else:
            assert_(options.matrix_type == 'elasticity')
            term = Term.new('dw_lin_elastic_iso(m.lam, m.mu, v, u)',
                            integral, omega, m=m, v=v, u=u)
            n_zero = (dim + 1) * dim / 2

        term.setup()

        output('assembling...')
        tt = time.clock()
        mtx, iels = term.evaluate(mode='weak', diff_var='u')
        output('...done in %.2f s' % (time.clock() - tt))
        mtx = mtx[0][0, 0]

        try:
            assert_(nm.max(nm.abs(mtx - mtx.T)) < 1e-10)

        except:
            from sfepy.base.base import debug; debug()

        output('matrix shape:', mtx.shape)

        eigs = eig(mtx, method='eig.sgscipy', eigenvectors=False)
        eigs.sort()

        # Zero 'true' zeros.
        eigs[:n_zero] = 0.0

        ii = nm.where(eigs < 0.0)[0]
        if len(ii):
            output('matrix is not positive semi-definite!')

        ii = nm.where(eigs[n_zero:] < 1e-12)[0]
        if len(ii):
            output('matrix has more than %d zero eigenvalues!' % n_zero)

        output('smallest eigs:\n', eigs[:10])

        ii = nm.where(eigs > 0.0)[0]
        emin, emax = eigs[ii[[0, -1]]]

        output('min:', emin, 'max:', emax)

        cond = emax / emin
        conds.append(cond)

        output('condition number:', cond)

        output('...done')

    plt.figure(1)
    plt.semilogy(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel('polynomial order')
    plt.ylabel('condition number')
    plt.grid()

    plt.figure(2)
    plt.loglog(orders, conds)
    plt.xticks(orders, orders)
    plt.xlabel('polynomial order')
    plt.ylabel('condition number')
    plt.grid()

    plt.show()