Exemple #1
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    def test_interpolation_two_meshes(self):
        from sfepy import data_dir
        from sfepy.fem import Mesh, Domain, H1NodalVolumeField, Variables

        m1 = Mesh('source mesh', data_dir + '/meshes/3d/block.mesh')

        m2 = Mesh('target mesh',
                  data_dir + '/meshes/3d/cube_medium_tetra.mesh')
        m2.coors *= 2.0

        bbox = m1.get_bounding_box()
        dd = bbox[1, :] - bbox[0, :]
        data = nm.sin(4.0 * nm.pi * m1.coors[:,0:1] / dd[0]) \
               * nm.cos(4.0 * nm.pi * m1.coors[:,1:2] / dd[1])

        variables1 = {
            'u': ('unknown field', 'scalar_tp', 0),
            'v': ('test field', 'scalar_tp', 'u'),
        }

        variables2 = {
            'u': ('unknown field', 'scalar_si', 0),
            'v': ('test field', 'scalar_si', 'u'),
        }

        d1 = Domain('d1', m1)
        omega1 = d1.create_region('Omega', 'all')
        field1 = H1NodalVolumeField('scalar_tp',
                                    nm.float64, (1, 1),
                                    omega1,
                                    approx_order=1)
        ff1 = {field1.name: field1}

        d2 = Domain('d2', m2)
        omega2 = d2.create_region('Omega', 'all')
        field2 = H1NodalVolumeField('scalar_si',
                                    nm.float64, (1, 1),
                                    omega2,
                                    approx_order=0)
        ff2 = {field2.name: field2}

        vv1 = Variables.from_conf(transform_variables(variables1), ff1)
        u1 = vv1['u']
        u1.set_from_mesh_vertices(data)

        vv2 = Variables.from_conf(transform_variables(variables2), ff2)
        u2 = vv2['u']

        # Performs interpolation, if other field differs from self.field
        # or, in particular, is defined on a different mesh.
        u2.set_from_other(u1, strategy='interpolation', close_limit=0.1)

        fname = in_dir(self.options.out_dir)
        u1.save_as_mesh(fname('test_mesh_interp_block_scalar.vtk'))
        u2.save_as_mesh(fname('test_mesh_interp_cube_scalar.vtk'))

        return True
Exemple #2
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def do_interpolation(m2, m1, data, field_name, force=False):
    """Interpolate data from m1 to m2. """
    from sfepy.fem import Domain, H1NodalVolumeField, Variables

    fields = {
        'scalar_si': ((1, 1), 'Omega', 2),
        'vector_si': ((3, 1), 'Omega', 2),
        'scalar_tp': ((1, 1), 'Omega', 1),
        'vector_tp': ((3, 1), 'Omega', 1),
    }

    d1 = Domain('d1', m1)

    omega1 = d1.create_region('Omega', 'all')

    f = fields[field_name]

    field1 = H1NodalVolumeField('f',
                                nm.float64,
                                f[0],
                                d1.regions[f[1]],
                                approx_order=f[2])
    ff = {field1.name: field1}

    vv = Variables.from_conf(transform_variables(variables), ff)
    u1 = vv['u']
    u1.set_from_mesh_vertices(data)

    d2 = Domain('d2', m2)
    omega2 = d2.create_region('Omega', 'all')

    field2 = H1NodalVolumeField('f',
                                nm.float64,
                                f[0],
                                d2.regions[f[1]],
                                approx_order=f[2])
    ff2 = {field2.name: field2}

    vv2 = Variables.from_conf(transform_variables(variables), ff2)
    u2 = vv2['u']

    if not force:
        # Performs interpolation, if other field differs from self.field
        # or, in particular, is defined on a different mesh.
        u2.set_from_other(u1, strategy='interpolation', close_limit=0.5)

    else:
        coors = u2.field.get_coor()
        vals = u1.evaluate_at(coors, close_limit=0.5)
        u2.set_data(vals)

    return u1, u2
Exemple #3
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    def test_refine_3_8(self):
        mesh = Mesh('3_8', data_dir + '/meshes/elements/3_8_1.mesh')
        domain = refine(Domain('domain', mesh), self.options.out_dir, 1)

        ok = compare_mesh('3_8', domain.mesh.coors, domain.mesh.conns[0])

        return ok
Exemple #4
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    def from_conf(conf, options):
        import sfepy
        from sfepy.fem import Mesh, Domain, H1NodalVolumeField
        mesh = Mesh.from_file('meshes/2d/rectangle_tri.mesh',
                              prefix_dir=sfepy.data_dir)
        domain = Domain('domain', mesh)
        dim = domain.shape.dim

        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',
                                      'vertices in x < %.10f' % (min_x + eps),
                                      'facet')
        gamma2 = domain.create_region('Gamma2',
                                      'vertices in x > %.10f' % (max_x - eps),
                                      'facet')

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

        test = Test(conf=conf,
                    options=options,
                    dim=dim,
                    omega=omega,
                    gamma1=gamma1,
                    gamma2=gamma2,
                    field=field)
        return test
Exemple #5
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def refine_mesh(filename, level):
    """
    Uniformly refine `level`-times a mesh given by `filename`.

    The refined mesh is saved to a file with name constructed from base
    name of `filename` and `level`-times appended `'_r'` suffix.

    Parameters
    ----------
    filename : str
        The mesh file name.
    level : int
        The refinement level.
    """
    import os
    from sfepy.base.base import output
    from sfepy.fem import Mesh, Domain

    if level > 0:
        mesh = Mesh.from_file(filename)
        domain = Domain(mesh.name, mesh)
        for ii in range(level):
            output('refine %d...' % ii)
            domain = domain.refine()
            output('... %d nodes %d elements'
                   % (domain.shape.n_nod, domain.shape.n_el))

        suffix = os.path.splitext(filename)[1]
        filename = domain.name + suffix

        domain.mesh.write(filename, io='auto')

    return filename
Exemple #6
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def main():
    parser = OptionParser(usage=usage, version="%prog")

    options, args = parser.parse_args()

    if (len(args) == 1):
        mesh_filename = args[0];
    else:
        parser.print_help(),
        return

    mesh = Mesh('mesh', mesh_filename)
    print mesh

    domain = Domain('domain', mesh)
    print domain

    reg = domain.create_region('Surface',
                               'nodes of surface',
                               {'can_cells' : True})

    dual_mesh = DualMesh(reg)
    dual_mesh.save('dual_mesh.mesh',)
    dual_mesh.save_axes('axes.vtk',)

    print dual_mesh
Exemple #7
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    def test_refine_hexa(self):
        mesh = Mesh('mesh_hexa',
                    data_dir + '/meshes/various_formats/abaqus_hex.inp')
        domain = Domain('domain', mesh)

        refine(domain, self.options.out_dir)

        return True
Exemple #8
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    def from_conf(conf, options):
        mesh = Mesh.from_file('meshes/2d/square_unit_tri.mesh',
                              prefix_dir=sfepy.data_dir)
        domain = Domain('domain', mesh)

        omega = domain.create_region('Omega', 'all')

        field = H1NodalVolumeField('linear', nm.float64, 'scalar', omega,
                                   approx_order=1)

        test = Test(conf=conf, options=options, omega=omega, field=field)
        return test
Exemple #9
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    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
Exemple #10
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    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
Exemple #11
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    def test_projection_tri_quad(self):
        from sfepy.fem.projections import make_l2_projection

        source = FieldVariable('us', 'unknown', self.field, 1)

        coors = self.field.get_coor()
        vals = nm.sin(2.0 * nm.pi * coors[:, 0] * coors[:, 1])
        source.data_from_any(vals)

        name = op.join(self.options.out_dir,
                       'test_projection_tri_quad_source.vtk')
        source.save_as_mesh(name)

        mesh = Mesh.from_file('meshes/2d/square_quad.mesh',
                              prefix_dir=sfepy.data_dir)
        domain = Domain('domain', mesh)

        omega = domain.create_region('Omega', 'all')

        field = H1NodalVolumeField('bilinear',
                                   nm.float64,
                                   'scalar',
                                   omega,
                                   approx_order=1)

        target = FieldVariable('ut', 'unknown', field, 1)

        make_l2_projection(target, source)

        name = op.join(self.options.out_dir,
                       'test_projection_tri_quad_target.vtk')
        target.save_as_mesh(name)

        bbox = self.field.domain.get_mesh_bounding_box()
        x = nm.linspace(bbox[0, 0] + 0.001, bbox[1, 0] - 0.001, 20)
        y = nm.linspace(bbox[0, 1] + 0.001, bbox[1, 1] - 0.001, 20)

        xx, yy = nm.meshgrid(x, y)
        test_coors = nm.c_[xx.ravel(), yy.ravel()].copy()

        vec1 = source.evaluate_at(test_coors)
        vec2 = target.evaluate_at(test_coors)

        ok = (nm.abs(vec1 - vec2) < 0.01).all()

        return ok
Exemple #12
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    def from_conf(conf, options):
        from sfepy import data_dir
        from sfepy.fem import Mesh, Domain, Functions

        mesh = Mesh('test mesh',
                    data_dir + '/meshes/various_formats/abaqus_tet.inp')
        domain = Domain('test domain', mesh)

        conf_functions = {
            'get_nodes': (get_nodes, ),
            'get_elements': (get_elements, ),
        }
        functions = Functions.from_conf(transform_functions(conf_functions))

        test = Test(conf=conf,
                    options=options,
                    domain=domain,
                    functions=functions)
        return test
Exemple #13
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    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
Exemple #14
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def mesh_hook(mesh, mode):
    """
    Load and refine a mesh here.
    """
    if mode == 'read':
        mesh = Mesh.from_file(base_mesh)
        domain = Domain(mesh.name, mesh)
        for ii in range(3):
            output('refine %d...' % ii)
            domain = domain.refine()
            output('... %d nodes %d elements' %
                   (domain.shape.n_nod, domain.shape.n_el))

        domain.mesh.name = '2_4_2_refined'

        return domain.mesh

    elif mode == 'write':
        pass
Exemple #15
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    def from_conf(conf, options):
        from sfepy import data_dir
        from sfepy.fem import Mesh, Domain, Functions

        mesh = Mesh('test mesh',
                    data_dir + '/meshes/various_formats/abaqus_tet.inp')
        mesh.nodal_bcs['set0'] = [0, 7]
        domain = Domain('test domain', mesh)

        conf_functions = {
            'get_vertices': (get_vertices, ),
            'get_cells': (get_cells, ),
        }
        functions = Functions.from_conf(transform_functions(conf_functions))

        test = Test(conf=conf,
                    options=options,
                    domain=domain,
                    functions=functions)
        return test
    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
Exemple #17
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def main():
    parser = OptionParser(usage=usage, version='%prog')
    options, args = parser.parse_args()

    if len(args) == 1:
        filename = args[0]
    else:
        parser.print_help(),
        return

    mesh = Mesh.from_file(filename)
    output('Mesh:')
    output('  dimension: %d, vertices: %d, elements: %d' %
           (mesh.dim, mesh.n_nod, mesh.n_el))

    domain = Domain('domain', mesh)
    output(domain.cmesh)
    domain.cmesh.cprint(1)
    dim = domain.cmesh.dim

    ax = pc.plot_wireframe(None, domain.cmesh)

    ax = pc.plot_entities(ax, domain.cmesh, 0, 'k')
    ax = pc.label_global_entities(ax, domain.cmesh, 0, 'k', 12)
    ax = pc.label_local_entities(ax, domain.cmesh, 0, 'k', 8)

    ax = pc.plot_entities(ax, domain.cmesh, 1, 'b')
    ax = pc.label_global_entities(ax, domain.cmesh, 1, 'b', 12)
    ax = pc.label_local_entities(ax, domain.cmesh, 1, 'b', 8)

    if dim == 3:
        ax = pc.plot_entities(ax, domain.cmesh, 2, 'g')
        ax = pc.label_global_entities(ax, domain.cmesh, 2, 'g', 12)
        ax = pc.label_local_entities(ax, domain.cmesh, 2, 'g', 8)

    ax = pc.plot_entities(ax, domain.cmesh, dim, 'r')
    ax = pc.label_global_entities(ax, domain.cmesh, dim, 'r', 12)

    pc.plt.show()
Exemple #18
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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)
Exemple #19
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def refine_reference(geometry, level):
    """
    Refine reference element given by `geometry`.

    Notes
    -----
    The error edges must be generated in the order of the connectivity
    of the previous (lower) level.
    """
    from sfepy.fem import Domain
    from sfepy.fem.geometry_element import geometry_data

    gcoors, gconn = geometry.coors, geometry.conn
    if level == 0:
        return gcoors, gconn

    gd = geometry_data[geometry.name]
    conn = nm.array([gd.conn], dtype=nm.int32)
    mat_id = conn[:, 0].copy()
    mat_id[:] = 0

    mesh = Mesh.from_data('aux', gd.coors, None, [conn], [mat_id],
                          [geometry.name])
    domain = Domain('aux', mesh)

    for ii in range(level):
        domain = domain.refine()

    coors = domain.mesh.coors
    conn = domain.mesh.conns[0]

    n_el = conn.shape[0]

    if geometry.name == '2_3':
        aux_conn = conn.reshape((n_el / 4, 4, 3))

        ir = [[0, 1, 2], [2, 2, 3], [3, 3, 0]]
        ic = [[0, 0, 0], [0, 1, 0], [0, 1, 0]]

    elif geometry.name == '2_4':
        aux_conn = conn.reshape((n_el / 4, 4, 4))

        ir = [[0, 0, 1], [1, 1, 2], [2, 2, 3], [3, 3, 0], [0, 0, 2], [3, 3, 1]]
        ic = [[0, 1, 0], [0, 1, 0], [0, 1, 0], [0, 1, 0], [1, 2, 1], [1, 2, 1]]

    elif geometry.name == '3_4':
        aux_conn = conn.reshape((n_el / 8, 8, 4))

        ir = [[0, 0, 1], [1, 1, 2], [2, 0, 0], [3, 1, 1], [3, 2, 2], [3, 0, 0]]
        ic = [[0, 1, 1], [1, 2, 2], [2, 2, 0], [3, 3, 1], [3, 3, 2], [3, 3, 0]]

    elif geometry.name == '3_8':
        aux_conn = conn.reshape((n_el / 8, 8, 8))

        ir = [[0, 0, 1], [1, 1, 2], [2, 2, 3], [3, 0, 0], [0, 0, 2], [0, 0, 1],
              [0, 0, 1], [1, 1, 2], [2, 2, 3], [3, 0, 0], [0, 0, 2], [0, 0, 1],
              [4, 4, 5], [5, 5, 6], [6, 6, 7], [7, 4, 4], [4, 4, 6], [4, 4, 5],
              [0, 0, 4], [1, 1, 5], [2, 2, 6], [3, 3, 7], [0, 0, 4], [1, 1, 5],
              [2, 2, 6], [0, 0, 4], [0, 0, 4]]
        ic = [[0, 1, 0], [0, 1, 0], [0, 1, 0], [0, 3, 0], [1, 2, 1], [3, 2, 1],
              [4, 5, 4], [4, 5, 4], [4, 5, 4], [4, 7, 4], [5, 6, 5], [7, 6, 5],
              [0, 3, 0], [0, 3, 0], [0, 3, 0], [0, 1, 0], [3, 2, 3], [1, 2, 3],
              [0, 4, 0], [0, 4, 0], [0, 4, 0], [0, 4, 0], [1, 5, 3], [1, 5, 3],
              [1, 5, 3], [3, 7, 1], [2, 6, 2]]

    else:
        raise ValueError('unsupported geometry! (%s)' % geometry.name)

    conn = nm.array(conn, dtype=nm.int32)
    error_edges = aux_conn[:, ir, ic]

    return coors, conn, error_edges
Exemple #20
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def save_basis_on_mesh(mesh,
                       options,
                       output_dir,
                       lin,
                       permutations=None,
                       suffix=''):
    if permutations is not None:
        mesh = mesh.copy()
        for ig, conn in enumerate(mesh.conns):
            gel = GeometryElement(mesh.descs[ig])
            perms = gel.get_conn_permutations()[permutations]
            n_el, n_ep = conn.shape
            offsets = nm.arange(n_el) * n_ep

            conn[:] = conn.take(perms + offsets[:, None])

    domain = Domain('domain', mesh)

    omega = domain.create_region('Omega', 'all')
    field = Field.from_args('f',
                            nm.float64,
                            shape=1,
                            region=omega,
                            approx_order=options.max_order,
                            poly_space_base=options.basis)
    var = FieldVariable('u', 'unknown', field, 1)

    if options.plot_dofs:
        import sfepy.postprocess.plot_dofs as pd
        group = domain.groups[0]
        ax = pd.plot_mesh(None, mesh.coors, mesh.conns[0], group.gel.edges)
        ax = pd.plot_global_dofs(ax, field.get_coor(), field.aps[0].econn)
        ax = pd.plot_local_dofs(ax, field.get_coor(), field.aps[0].econn)
        if options.dofs is not None:
            ax = pd.plot_nodes(ax, field.get_coor(), field.aps[0].econn,
                               field.aps[0].interp.poly_spaces['v'].nodes,
                               get_dofs(options.dofs, var.n_dof))
        pd.plt.show()

    output('dofs: %d' % var.n_dof)

    vec = nm.empty(var.n_dof, dtype=var.dtype)
    n_digit, _format = get_print_info(var.n_dof, fill='0')
    name_template = os.path.join(output_dir,
                                 'dof_%s%s.vtk' % (_format, suffix))
    for ip in get_dofs(options.dofs, var.n_dof):
        output('dof %d...' % ip)

        vec.fill(0.0)
        vec[ip] = 1.0

        var.set_data(vec)

        if options.derivative == 0:
            out = var.create_output(vec, linearization=lin)

        else:
            out = create_expression_output('ev_grad.ie.Elements(u)',
                                           'u',
                                           'f', {'f': field},
                                           None,
                                           Variables([var]),
                                           mode='qp',
                                           verbose=False,
                                           min_level=lin.min_level,
                                           max_level=lin.max_level,
                                           eps=lin.eps)

        name = name_template % ip
        ensure_path(name)
        out['u'].mesh.write(name, out=out)

        output('...done (%s)' % name)
Exemple #21
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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)
Exemple #22
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def main():
    parser = OptionParser(usage=usage, version="%prog " + sfepy.__version__)
    parser.add_option("-m",
                      "--mesh",
                      action="store_true",
                      dest="save_mesh",
                      default=True,
                      help="save surface mesh [default: %default]")
    parser.add_option("-n",
                      "--no-surface",
                      action="store_true",
                      dest="no_surface",
                      default=False,
                      help="do not output surface [default: %default]")
    (options, args) = parser.parse_args()

    if (len(args) == 2):
        filename_in = args[0]
        filename_out = args[1]
    else:
        parser.print_help(),
        return

    if (filename_in == '-'):
        file_in = sys.stdin
    else:
        file_in = open(filename_in, "r")

    mesh = Mesh.from_file(filename_in)

    if (filename_in != '-'):
        file_in.close()

    domain = Domain('domain', mesh)
    domain.setup_groups()

    if domain.has_faces():
        domain.fix_element_orientation()
        domain.setup_facets(create_edges=False)

        lst, surf_faces = domain.surface_faces()

        surf_mesh = Mesh.from_surface(surf_faces, mesh)

        if options.save_mesh:
            aux = edit_filename(filename_in, prefix='surf_', new_ext='.mesh')
            surf_mesh.write(aux, io='auto')

        if options.no_surface:
            return

        gr_s = surface_graph(surf_faces, mesh.n_nod)
        ##         import sfepy.base.plotutils as plu
        ##         plu.spy( gr_s )
        ##         plu.pylab.show()

        n_comp, comps = surface_components(gr_s, surf_faces)
        #        print 'components:', n_comp

        ccs, comps = comps, nm.zeros((0, 1), nm.int32)
        for cc in ccs:
            comps = nm.concatenate((comps, cc[:, nm.newaxis]), 0)

        out = nm.concatenate((lst, comps), 1)

        if (filename_out == '-'):
            file_out = sys.stdout
        else:
            file_out = open(filename_out, "w")
        for row in out:
            file_out.write('%d %d %d %d\n' % (row[0], row[1], row[2], row[3]))
        if (filename_out != '-'):
            file_out.close()
Exemple #23
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def smooth_mesh(mesh, n_iter=4, lam=0.6307, mu=-0.6347,
                weights=None, bconstr=True,
                volume_corr=False):
    """
    FE mesh smoothing.

    Based on:

    [1] Steven K. Boyd, Ralph Muller, Smooth surface meshing for automated
    finite element model generation from 3D image data, Journal of
    Biomechanics, Volume 39, Issue 7, 2006, Pages 1287-1295,
    ISSN 0021-9290, 10.1016/j.jbiomech.2005.03.006.
    (http://www.sciencedirect.com/science/article/pii/S0021929005001442)

    Parameters
    ----------
    mesh : mesh
        FE mesh.
    n_iter : integer, optional
        Number of iteration steps.
    lam : float, optional
        Smoothing factor, see [1].
    mu : float, optional
        Unshrinking factor, see [1].
    weights : array, optional
        Edge weights, see [1].
    bconstr: logical, optional
        Boundary constraints, if True only surface smoothing performed.
    volume_corr: logical, optional
        Correct volume after smoothing process.

    Returns
    -------
    coors : array
        Coordinates of mesh nodes.
    """

    def laplacian(coors, weights):

        n_nod = coors.shape[0]
        displ = (weights - sps.identity(n_nod)) * coors

        return displ

    def taubin(coors0, weights, lam, mu, n_iter):

        coors = coors0.copy()

        for ii in range(n_iter):
            displ = laplacian(coors, weights)
            if nm.mod(ii, 2) == 0:
                coors += lam * displ
            else:
                coors += mu * displ

        return coors

    def get_volume(el, nd):
        from sfepy.linalg.utils import dets_fast

        dim = nd.shape[1]
        nnd = el.shape[1]

        etype = '%d_%d' % (dim, nnd)
        if etype == '2_4' or etype == '3_8':
            el = elems_q2t(el)

        nel = el.shape[0]

        #bc = nm.zeros((dim, ), dtype=nm.double)
        mul = 1.0 / factorial(dim)
        if dim == 3:
            mul *= -1.0

        mtx = nm.ones((nel, dim + 1, dim + 1), dtype=nm.double)
        mtx[:,:,:-1] = nd[el,:]
        vols = mul * dets_fast(mtx.copy())
        vol = vols.sum()
        bc = nm.dot(vols, mtx.sum(1)[:,:-1] / nnd)

        bc /= vol

        return vol, bc

    import time

    output('smoothing...')
    tt = time.clock()

    if weights is None:
        n_nod = mesh.n_nod
        domain = Domain('mesh', mesh)
        cmesh = domain.cmesh

        # initiate all vertices as inner - hierarchy = 2
        node_group = nm.ones((n_nod,), dtype=nm.int16) * 2
        # boundary vertices - set hierarchy = 4
        if bconstr:
            # get "vertices of surface"
            facets = cmesh.get_surface_facets()
            f_verts = cmesh.get_incident(0, facets, cmesh.dim - 1)
            node_group[f_verts] = 4

        # generate costs matrix
        e_verts = cmesh.get_conn(1, 0).indices
        fc1, fc2 = e_verts[0::2], e_verts[1::2]
        idxs = nm.where(node_group[fc2] >= node_group[fc1])
        rows1 = fc1[idxs]
        cols1 = fc2[idxs]
        idxs = nm.where(node_group[fc1] >= node_group[fc2])
        rows2 = fc2[idxs]
        cols2 = fc1[idxs]
        crows = nm.concatenate((rows1, rows2))
        ccols = nm.concatenate((cols1, cols2))
        costs = sps.coo_matrix((nm.ones_like(crows), (crows, ccols)),
                               shape=(n_nod, n_nod),
                               dtype=nm.double)

        # generate weights matrix
        idxs = range(n_nod)
        aux = sps.coo_matrix((1.0 / nm.asarray(costs.sum(1)).squeeze(),
                              (idxs, idxs)),
                             shape=(n_nod, n_nod),
                             dtype=nm.double)

        #aux.setdiag(1.0 / costs.sum(1))
        weights = (aux.tocsc() * costs.tocsc()).tocsr()

    coors = taubin(mesh.coors, weights, lam, mu, n_iter)

    output('...done in %.2f s' % (time.clock() - tt))

    if volume_corr:
        output('rescaling...')
        volume0, bc = get_volume(mesh.conns[0], mesh.coors)
        volume, _ = get_volume(mesh.conns[0], coors)

        scale = volume0 / volume
        output('scale factor: %.2f' % scale)

        coors = (coors - bc) * scale + bc

        output('...done in %.2f s' % (time.clock() - tt))

    return coors
Exemple #24
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def smooth_mesh(mesh,
                n_iter=4,
                lam=0.6307,
                mu=-0.6347,
                weights=None,
                bconstr=True,
                volume_corr=False):
    """
    FE mesh smoothing.

    Based on:

    [1] Steven K. Boyd, Ralph Muller, Smooth surface meshing for automated
    finite element model generation from 3D image data, Journal of
    Biomechanics, Volume 39, Issue 7, 2006, Pages 1287-1295,
    ISSN 0021-9290, 10.1016/j.jbiomech.2005.03.006.
    (http://www.sciencedirect.com/science/article/pii/S0021929005001442)

    Parameters
    ----------
    mesh : mesh
        FE mesh.
    n_iter : integer, optional
        Number of iteration steps.
    lam : float, optional
        Smoothing factor, see [1].
    mu : float, optional
        Unshrinking factor, see [1].
    weights : array, optional
        Edge weights, see [1].
    bconstr: logical, optional
        Boundary constraints, if True only surface smoothing performed.
    volume_corr: logical, optional
        Correct volume after smoothing process.

    Returns
    -------
    coors : array
        Coordinates of mesh nodes.
    """
    def laplacian(coors, weights):

        n_nod = coors.shape[0]
        displ = (weights - sps.identity(n_nod)) * coors

        return displ

    def taubin(coors0, weights, lam, mu, n_iter):

        coors = coors0.copy()

        for ii in range(n_iter):
            displ = laplacian(coors, weights)
            if nm.mod(ii, 2) == 0:
                coors += lam * displ
            else:
                coors += mu * displ

        return coors

    def get_volume(el, nd):

        dim = nd.shape[1]
        nnd = el.shape[1]

        etype = '%d_%d' % (dim, nnd)
        if etype == '2_4' or etype == '3_8':
            el = elems_q2t(el)

        vol = 0.0
        bc = nm.zeros((dim, ), dtype=nm.double)
        mtx = nm.ones((dim + 1, dim + 1), dtype=nm.double)
        mul = 1.0 / sc.factorial(dim)
        if dim == 3:
            mul *= -1.0

        for iel in el:
            mtx[:, :-1] = nd[iel, :]
            ve = mul * nm.linalg.det(mtx)
            vol += ve
            bc += ve * mtx.sum(0)[:-1] / nnd

        bc /= vol

        return vol, bc

    domain = Domain('mesh', mesh)

    n_nod = mesh.n_nod
    edges = domain.ed

    if weights is None:
        # initiate all vertices as inner - hierarchy = 2
        node_group = nm.ones((n_nod, ), dtype=nm.int16) * 2
        # boundary vertices - set hierarchy = 4
        if bconstr:
            # get "nodes of surface"
            if domain.fa:  # 3D.
                fa = domain.fa
            else:
                fa = domain.ed

            flag = fa.mark_surface_facets()
            ii = nm.where(flag > 0)[0]
            aux = nm.unique(fa.facets[ii])
            if aux[0] == -1:  # Triangular faces have -1 as 4. point.
                aux = aux[1:]

            node_group[aux] = 4

        # generate costs matrix
        costs = sps.lil_matrix((n_nod, n_nod), dtype=nm.double)
        for ied in range(edges.mtx.shape[0]):
            cc = edges.mtx.getrow(ied).indices[0]
            n1, n2 = edges.facets[cc, :]
            if node_group[n2] >= node_group[n1]:
                costs[n1, n2] = 1.0

            if node_group[n1] >= node_group[n2]:
                costs[n2, n1] = 1.0

        # generate weights matrix
        aux = sps.lil_matrix((n_nod, n_nod), dtype=nm.double)
        aux.setdiag(1.0 / costs.sum(1))
        weights = (aux * costs).tocsr()

    coors = taubin(mesh.coors, weights, lam, mu, n_iter)

    if volume_corr:

        volume0, bc = get_volume(mesh.conns[0], mesh.coors)
        volume, _ = get_volume(mesh.conns[0], coors)

        scale = volume0 / volume

        coors = (coors - bc) * scale + bc

    return coors
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()
Exemple #26
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('-d',
                      '--derivative',
                      metavar='d',
                      type=int,
                      action='store',
                      dest='derivative',
                      default=0,
                      help=help['derivative'])
    parser.add_option('-n',
                      '--max-order',
                      metavar='order',
                      type=int,
                      action='store',
                      dest='max_order',
                      default=2,
                      help=help['max_order'])
    parser.add_option('-g',
                      '--geometry',
                      metavar='name',
                      action='store',
                      dest='geometry',
                      default='2_4',
                      help=help['geometry'])
    parser.add_option('-m',
                      '--mesh',
                      metavar='mesh',
                      action='store',
                      dest='mesh',
                      default=None,
                      help=help['mesh'])
    parser.add_option('',
                      '--permutations',
                      metavar='permutations',
                      action='store',
                      dest='permutations',
                      default=None,
                      help=help['permutations'])
    parser.add_option('',
                      '--dofs',
                      metavar='dofs',
                      action='store',
                      dest='dofs',
                      default=None,
                      help=help['dofs'])
    parser.add_option('-l',
                      '--lin-options',
                      metavar='options',
                      action='store',
                      dest='lin_options',
                      default='min_level=2,max_level=5,eps=1e-3',
                      help=help['lin_options'])
    parser.add_option('',
                      '--plot-dofs',
                      action='store_true',
                      dest='plot_dofs',
                      default=False,
                      help=help['plot_dofs'])
    options, args = parser.parse_args()

    if len(args) == 1:
        output_dir = args[0]
    else:
        parser.print_help(),
        return

    output('polynomial space:', options.basis)
    output('max. order:', options.max_order)

    lin = Struct(kind='adaptive', min_level=2, max_level=5, eps=1e-3)
    for opt in options.lin_options.split(','):
        key, val = opt.split('=')
        setattr(lin, key, eval(val))

    if options.mesh is None:
        dim, n_ep = int(options.geometry[0]), int(options.geometry[2])
        output('reference element geometry:')
        output('  dimension: %d, vertices: %d' % (dim, n_ep))

        gel = GeometryElement(options.geometry)
        gps = PolySpace.any_from_args(None, gel, 1, base=options.basis)
        ps = PolySpace.any_from_args(None,
                                     gel,
                                     options.max_order,
                                     base=options.basis)

        n_digit, _format = get_print_info(ps.n_nod, fill='0')
        name_template = os.path.join(output_dir, 'bf_%s.vtk' % _format)
        for ip in get_dofs(options.dofs, ps.n_nod):
            output('shape function %d...' % ip)

            def eval_dofs(iels, rx):
                if options.derivative == 0:
                    bf = ps.eval_base(rx).squeeze()
                    rvals = bf[None, :, ip:ip + 1]

                else:
                    bfg = ps.eval_base(rx, diff=True)
                    rvals = bfg[None, ..., ip]

                return rvals

            def eval_coors(iels, rx):
                bf = gps.eval_base(rx).squeeze()
                coors = nm.dot(bf, gel.coors)[None, ...]
                return coors

            (level, coors, conn, vdofs,
             mat_ids) = create_output(eval_dofs,
                                      eval_coors,
                                      1,
                                      ps,
                                      min_level=lin.min_level,
                                      max_level=lin.max_level,
                                      eps=lin.eps)
            out = {
                'bf':
                Struct(name='output_data',
                       mode='vertex',
                       data=vdofs,
                       var_name='bf',
                       dofs=None)
            }

            mesh = Mesh.from_data('bf_mesh', coors, None, [conn], [mat_ids],
                                  [options.geometry])

            name = name_template % ip
            mesh.write(name, out=out)

            output('...done (%s)' % name)

    else:
        mesh = Mesh.from_file(options.mesh)
        output('mesh geometry:')
        output('  dimension: %d, vertices: %d, elements: %d' %
               (mesh.dim, mesh.n_nod, mesh.n_el))

        domain = Domain('domain', mesh)

        if options.permutations:
            permutations = [int(ii) for ii in options.permutations.split(',')]
            output('using connectivity permutations:', permutations)
            for group in domain.iter_groups():
                perms = group.gel.get_conn_permutations()[permutations]
                offsets = nm.arange(group.shape.n_el) * group.shape.n_ep

                group.conn[:] = group.conn.take(perms + offsets[:, None])

            domain.setup_facets()

        omega = domain.create_region('Omega', 'all')
        field = Field.from_args('f',
                                nm.float64,
                                shape=1,
                                region=omega,
                                approx_order=options.max_order,
                                poly_space_base=options.basis)
        var = FieldVariable('u', 'unknown', field, 1)

        if options.plot_dofs:
            import sfepy.postprocess.plot_dofs as pd
            group = domain.groups[0]
            ax = pd.plot_mesh(None, mesh.coors, mesh.conns[0], group.gel.edges)
            ax = pd.plot_global_dofs(ax, field.get_coor(), field.aps[0].econn)
            ax = pd.plot_local_dofs(ax, field.get_coor(), field.aps[0].econn)
            if options.dofs is not None:
                ax = pd.plot_nodes(ax, field.get_coor(), field.aps[0].econn,
                                   field.aps[0].interp.poly_spaces['v'].nodes,
                                   get_dofs(options.dofs, var.n_dof))
            pd.plt.show()

        output('dofs: %d' % var.n_dof)

        vec = nm.empty(var.n_dof, dtype=var.dtype)
        n_digit, _format = get_print_info(var.n_dof, fill='0')
        name_template = os.path.join(output_dir, 'dof_%s.vtk' % _format)
        for ip in get_dofs(options.dofs, var.n_dof):
            output('dof %d...' % ip)

            vec.fill(0.0)
            vec[ip] = 1.0

            var.set_data(vec)

            if options.derivative == 0:
                out = var.create_output(vec, linearization=lin)

            else:
                out = create_expression_output('ev_grad.ie.Elements(u)',
                                               'u',
                                               'f', {'f': field},
                                               None,
                                               Variables([var]),
                                               mode='qp',
                                               verbose=False,
                                               min_level=lin.min_level,
                                               max_level=lin.max_level,
                                               eps=lin.eps)

            name = name_template % ip
            out['u'].mesh.write(name, out=out)

            output('...done (%s)' % name)
Exemple #27
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def smooth_mesh(mesh,
                n_iter=4,
                lam=0.6307,
                mu=-0.6347,
                weights=None,
                bconstr=True,
                volume_corr=False):
    """
    FE mesh smoothing.

    Based on:

    [1] Steven K. Boyd, Ralph Muller, Smooth surface meshing for automated
    finite element model generation from 3D image data, Journal of
    Biomechanics, Volume 39, Issue 7, 2006, Pages 1287-1295,
    ISSN 0021-9290, 10.1016/j.jbiomech.2005.03.006.
    (http://www.sciencedirect.com/science/article/pii/S0021929005001442)

    Parameters
    ----------
    mesh : mesh
        FE mesh.
    n_iter : integer, optional
        Number of iteration steps.
    lam : float, optional
        Smoothing factor, see [1].
    mu : float, optional
        Unshrinking factor, see [1].
    weights : array, optional
        Edge weights, see [1].
    bconstr: logical, optional
        Boundary constraints, if True only surface smoothing performed.
    volume_corr: logical, optional
        Correct volume after smoothing process.

    Returns
    -------
    coors : array
        Coordinates of mesh nodes.
    """
    def laplacian(coors, weights):

        n_nod = coors.shape[0]
        displ = (weights - sps.identity(n_nod)) * coors

        return displ

    def taubin(coors0, weights, lam, mu, n_iter):

        coors = coors0.copy()

        for ii in range(n_iter):
            displ = laplacian(coors, weights)
            if nm.mod(ii, 2) == 0:
                coors += lam * displ
            else:
                coors += mu * displ

        return coors

    def dets_fast(a):
        m = a.shape[0]
        n = a.shape[1]
        lapack_routine = lapack_lite.dgetrf
        pivots = nm.zeros((m, n), intc)
        flags = nm.arange(1, n + 1).reshape(1, -1)
        for i in xrange(m):
            tmp = a[i]
            lapack_routine(n, n, tmp, n, pivots[i], 0)
        sign = 1. - 2. * (nm.add.reduce(pivots != flags, axis=1) % 2)
        idx = nm.arange(n)
        d = a[:, idx, idx]
        absd = nm.absolute(d)
        sign *= nm.multiply.reduce(d / absd, axis=1)
        nm.log(absd, absd)
        logdet = nm.add.reduce(absd, axis=-1)

        return sign * nm.exp(logdet)

    def get_volume(el, nd):

        dim = nd.shape[1]
        nnd = el.shape[1]

        etype = '%d_%d' % (dim, nnd)
        if etype == '2_4' or etype == '3_8':
            el = elems_q2t(el)

        nel = el.shape[0]

        #bc = nm.zeros((dim, ), dtype=nm.double)
        mul = 1.0 / factorial(dim)
        if dim == 3:
            mul *= -1.0

        mtx = nm.ones((nel, dim + 1, dim + 1), dtype=nm.double)
        mtx[:, :, :-1] = nd[el, :]
        vols = mul * dets_fast(mtx.copy())  # copy() ???
        vol = vols.sum()
        bc = nm.dot(vols, mtx.sum(1)[:, :-1] / nnd)

        bc /= vol

        return vol, bc

    import time

    output('smoothing...')
    tt = time.clock()

    domain = Domain('mesh', mesh)

    n_nod = mesh.n_nod
    edges = domain.ed

    if weights is None:
        # initiate all vertices as inner - hierarchy = 2
        node_group = nm.ones((n_nod, ), dtype=nm.int16) * 2
        # boundary vertices - set hierarchy = 4
        if bconstr:
            # get "nodes of surface"
            if domain.fa:  # 3D.
                fa = domain.fa
            else:
                fa = domain.ed

            flag = fa.mark_surface_facets()
            ii = nm.where(flag > 0)[0]
            aux = nm.unique(fa.facets[ii])
            if aux[0] == -1:  # Triangular faces have -1 as 4. point.
                aux = aux[1:]

            node_group[aux] = 4

        # generate costs matrix
        mtx_ed = edges.mtx.tocoo()
        _, idxs = nm.unique(mtx_ed.row, return_index=True)
        aux = edges.facets[mtx_ed.col[idxs]]
        fc1 = aux[:, 0]
        fc2 = aux[:, 1]
        idxs = nm.where(node_group[fc2] >= node_group[fc1])
        rows1 = fc1[idxs]
        cols1 = fc2[idxs]
        idxs = nm.where(node_group[fc1] >= node_group[fc2])
        rows2 = fc2[idxs]
        cols2 = fc1[idxs]
        crows = nm.concatenate((rows1, rows2))
        ccols = nm.concatenate((cols1, cols2))
        costs = sps.coo_matrix((nm.ones_like(crows), (crows, ccols)),
                               shape=(n_nod, n_nod),
                               dtype=nm.double)

        # generate weights matrix
        idxs = range(n_nod)
        aux = sps.coo_matrix(
            (1.0 / nm.asarray(costs.sum(1)).squeeze(), (idxs, idxs)),
            shape=(n_nod, n_nod),
            dtype=nm.double)

        #aux.setdiag(1.0 / costs.sum(1))
        weights = (aux.tocsc() * costs.tocsc()).tocsr()

    coors = taubin(mesh.coors, weights, lam, mu, n_iter)

    output('...done in %.2f s' % (time.clock() - tt))

    if volume_corr:
        output('rescaling...')
        volume0, bc = get_volume(mesh.conns[0], mesh.coors)
        volume, _ = get_volume(mesh.conns[0], coors)

        scale = volume0 / volume
        output('scale factor: %.2f' % scale)

        coors = (coors - bc) * scale + bc

        output('...done in %.2f s' % (time.clock() - tt))

    return coors
Exemple #28
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    def test_linearization(self):
        from sfepy.base.base import Struct
        from sfepy.fem import Mesh, Domain, H1NodalVolumeField
        from sfepy import data_dir

        geometries = ['2_3', '2_4', '3_4', '3_8']
        approx_orders = [1, 2]
        funs = [nm.cos, nm.sin, lambda x: x]

        ok = True
        for geometry in geometries:
            name = os.path.join(data_dir,
                                'meshes/elements/%s_1.mesh' % geometry)
            mesh = Mesh.from_file(name)

            domain = Domain('', mesh)
            domain = domain.refine()

            domain.mesh.write(self.join('linearizer-%s-0.mesh' % geometry))

            omega = domain.create_region('Omega', 'all')

            for approx_order in approx_orders:
                for dpn in [1, mesh.dim]:
                    self.report('geometry: %s, approx. order: %d, dpn: %d' %
                                (geometry, approx_order, dpn))

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

                    cc = field.get_coor()
                    dofs = nm.zeros((field.n_nod, dpn), dtype=nm.float64)

                    for ic in range(dpn):
                        dofs[:, ic] = funs[ic](3 * (cc[:, 0] * cc[:, 1]))

                    vmesh, vdofs, levels = field.linearize(dofs,
                                                           min_level=0,
                                                           max_level=3,
                                                           eps=1e-2)
                    level = levels[0]

                    if approx_order == 1:
                        _ok = level == 0

                    else:
                        _ok = level > 0
                    self.report('max. refinement level: %d: %s' % (level, _ok))

                    ok = ok and _ok

                    rdofs = nm.zeros((vmesh.n_nod, dpn), dtype=nm.float64)
                    cc = vmesh.coors
                    for ic in range(dpn):
                        rdofs[:, ic] = funs[ic](3 * (cc[:, 0] * cc[:, 1]))

                    _ok = nm.allclose(rdofs, vdofs, rtol=0.0, atol=0.03)
                    self.report('interpolation: %s' % _ok)
                    ok = ok and _ok

                    out = {
                        'u':
                        Struct(name='output_data',
                               mode='vertex',
                               data=vdofs,
                               var_name='u',
                               dofs=None)
                    }

                    name = self.join('linearizer-%s-%d-%d' %
                                     (geometry, approx_order, dpn))

                    vmesh.write(name + '.mesh')
                    vmesh.write(name + '.vtk', out=out)

        return ok
Exemple #29
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    def from_conf(conf, options):
        mesh = Mesh('mesh_tetra',
                    data_dir + '/meshes/various_formats/small3d.mesh')
        domain = Domain('domain', mesh)

        return Test(conf=conf, options=options, domain=domain)
Exemple #30
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def main():
    parser = OptionParser(usage=usage)
    parser.add_option('-s', '--scale', metavar='scale',
                      action='store', dest='scale',
                      default=None, help=help['scale'])
    parser.add_option('-r', '--refine', metavar='level',
                      action='store', type=int, dest='refine',
                      default=0, help=help['refine'])
    parser.add_option('-f', '--format', metavar='format',
                      action='store', type='string', dest='format',
                      default=None, help=help['format'])
    parser.add_option('-l', '--list', action='store_true',
                      dest='list', help=help['list'])
    (options, args) = parser.parse_args()

    if options.list:
        output_writable_meshes()
        sys.exit(0)

    if len(args) != 2:
        parser.print_help()
        sys.exit(1)

    scale = options.scale
    if scale is not None:
        try:
            try:
                scale = float(scale)
            except ValueError:
                scale = [float(ii) for ii in scale.split(',')]
            scale = nm.array(scale, dtype=nm.float64, ndmin=1)
        except:
            output('bad scale! (%s)' % scale)
            parser.print_help()
            sys.exit(1)

    filename_in, filename_out = args

    mesh = Mesh.from_file(filename_in)

    if scale is not None:
        if len(scale) == 1:
            tr = nm.eye(mesh.dim, dtype=nm.float64) * scale
        elif len(scale) == mesh.dim:
            tr = nm.diag(scale)
        else:
            raise ValueError('bad scale! (%s)' % scale)
        mesh.transform_coors(tr)

    if options.refine > 0:
        domain = Domain(mesh.name, mesh)
        output('initial mesh: %d nodes %d elements'
               % (domain.shape.n_nod, domain.shape.n_el))

        for ii in range(options.refine):
            output('refine %d...' % ii)
            domain = domain.refine()
            output('... %d nodes %d elements'
                   % (domain.shape.n_nod, domain.shape.n_el))

        mesh = domain.mesh

    io = MeshIO.for_format(filename_out, format=options.format,
                           writable=True)

    output('writing %s...' % filename_out)
    mesh.write(filename_out, io=io)
    output('...done')