Example #1
0
def test_example_03():
    set_verbose(False)

    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    from hermes2d.examples.c03 import set_bc

    set_bc(space)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)

    # assemble the stiffness matrix and solve the system
    sln = Solution()
    sys.assemble()
    sys.solve_system(sln)
    assert abs(sln.l2_norm() - 0.25493) < 1e-4
    assert abs(sln.h1_norm() - 0.89534) < 1e-4
Example #2
0
def test_matrix():
    set_verbose(False)

    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)

    # assemble the stiffness matrix and solve the system
    sln = Solution()
    sys.assemble()
    A = sys.get_matrix()
Example #3
0
def test_ScalarView_mpl_unknown():
    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)

    # assemble the stiffness matrix and solve the system
    sys.assemble()
    A = sys.get_matrix()
    b = sys.get_rhs()
    from scipy.sparse.linalg import cg
    x, res = cg(A, b)
    sln = Solution()
    sln.set_fe_solution(space, pss, x)

    view = ScalarView("Solution")
Example #4
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def test_ScalarView_mpl_unknown():
    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)

    # assemble the stiffness matrix and solve the system
    sys.assemble()
    A = sys.get_matrix()
    b = sys.get_rhs()
    from scipy.sparse.linalg import cg

    x, res = cg(A, b)
    sln = Solution()
    sln.set_fe_solution(space, pss, x)

    view = ScalarView("Solution")
Example #5
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def test_plot_mesh2():
    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)

    view = MeshView("Solution")
    view.show(mesh, lib="mpl", method="simple", show=False)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements, plot_nodes=False)
    view.show(mesh, lib="mpl", method="orders", show=False)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements)
Example #6
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def test_plot_mesh2():
    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)

    view = MeshView("Solution")
    view.show(mesh, lib="mpl", method="simple", show=False)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements, plot_nodes=False)
    view.show(mesh, lib="mpl", method="orders", show=False)
    plot_mesh_mpl(mesh.nodes_dict, mesh.elements)
Example #7
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def poisson_solver(rho, prec=0.1):
    """
    Solves the Poisson equation \Nabla^2\phi = \rho.

    prec ... the precision of the solution in percents

    Returns the solution.
    """
    mesh = Mesh()
    mesh.load("square.mesh")
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms_poisson(wf, rho)
    solver = DummySolver()

    # assemble the stiffness matrix and solve the system
    for i in range(10):
        sys = LinSystem(wf, solver)
        sys.set_spaces(space)
        sys.set_pss(pss)

        sln = Solution()
        print "poisson: assembly coarse"
        sys.assemble()
        print "poisson: done"
        sys.solve_system(sln)

        rp = RefSystem(sys)
        rsln = Solution()
        print "poisson: assembly reference"
        rp.assemble()
        print "poisson: done"
        rp.solve_system(rsln)

        hp = H1OrthoHP(space)
        error = hp.calc_error(sln, rsln) * 100
        print "iteration: %d, error: %f" % (i, error)
        if error < prec:
            print "Error less than %f%%, we are done." % prec
            break
        hp.adapt(0.3)
        space.assign_dofs()
    return sln
Example #8
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def main():
    set_verbose(False)
    mesh = Mesh()
    print "Loading mesh..."
    mesh.load(get_GAMM_channel_mesh())
    #mesh.load("domain-quad.mesh")
    #mesh.refine_element(0, 2)
    mesh.refine_element(1, 2)
    mesh.refine_all_elements()
    mesh.refine_all_elements()
    mesh.refine_all_elements()
    mesh.refine_all_elements()

    print "Constructing edges..."
    nodes = mesh.nodes_dict
    edges = Edges(mesh)
    elements = mesh.elements
    print "Done."

    print "Solving..."
    state_on_elements = {}
    for e in mesh.active_elements:
        state_on_elements[e.id] = array([1., 50., 0., 1.e5])
    #print "initial state"
    #print state_on_elements
    tau = 1e-3
    t = 0.
    for i in range(100):
        A, rhs, dof_map = assembly(edges, state_on_elements, tau)
        #print "A:"
        #print A
        #print "rhs:"
        #print rhs
        #stop
        #print "x:"
        x = spsolve(A, rhs)
        #print x
        #print state_on_elements
        state_on_elements = set_fvm_solution(x, dof_map)
        #print state_on_elements
        t += tau
        print "t = ", t
    plot_state(state_on_elements, mesh)
    #print "state_on_elements:"
    #print state_on_elements
    print "Done."
Example #9
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def test_matrix():
    set_verbose(False)

    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)

    # create an H1 space with default shapeset
    space = H1Space(mesh, 1)

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    sys = LinSystem(wf)
    sys.set_spaces(space)

    # assemble the stiffness matrix and solve the system
    sln = Solution()
    sys.assemble()
    A = sys.get_matrix()
Example #10
0
def test_matrix():
    set_verbose(False)

    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)

    # create an H1 space with default shapeset
    space = H1Space(mesh, 1)

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    sys = LinSystem(wf)
    sys.set_spaces(space)

    # assemble the stiffness matrix and solve the system
    sln = Solution()
    sys.assemble()
    A = sys.get_matrix()
Example #11
0
def test_example_02():
    set_verbose(False)

    mesh = Mesh()
    mesh.load(domain_mesh)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)
def poisson_solver(mesh_tuple):
    """
    Poisson solver.

    mesh_tuple ... a tuple of (nodes, elements, boundary, nurbs)
    """
    set_verbose(False)
    mesh = Mesh()
    mesh.create(*mesh_tuple)
    mesh.refine_element(0)
    shapeset = H1Shapeset()
    pss = PrecalcShapeset(shapeset)

    # create an H1 space
    space = H1Space(mesh, shapeset)
    space.set_uniform_order(5)
    space.assign_dofs()

    # initialize the discrete problem
    wf = WeakForm(1)
    set_forms(wf)

    solver = DummySolver()
    sys = LinSystem(wf, solver)
    sys.set_spaces(space)
    sys.set_pss(pss)

    # assemble the stiffness matrix and solve the system
    sys.assemble()
    A = sys.get_matrix()
    b = sys.get_rhs()
    from scipy.sparse.linalg import cg
    x, res = cg(A, b)
    sln = Solution()
    sln.set_fe_solution(space, pss, x)
    return sln
Example #13
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def test_example_11():
    from hermes2d.examples.c11 import set_bc, set_wf_forms, set_hp_forms

    # The following parameters can be changed: In particular, compare hp- and
    # h-adaptivity via the ADAPT_TYPE option, and compare the multi-mesh vs. single-mesh
    # using the MULTI parameter.
    P_INIT = 1  # Initial polynomial degree of all mesh elements.
    MULTI = True  # MULTI = true  ... use multi-mesh,
    # MULTI = false ... use single-mesh.
    # Note: In the single mesh option, the meshes are
    # forced to be geometrically the same but the
    # polynomial degrees can still vary.
    SAME_ORDERS = True  # SAME_ORDERS = true ... when single-mesh is used,
    # this forces the meshes for all components to be
    # identical, including the polynomial degrees of
    # corresponding elements. When multi-mesh is used,
    # this parameter is ignored.
    THRESHOLD = 0.3  # This is a quantitative parameter of the adapt(...) function and
    # it has different meanings for various adaptive strategies (see below).
    STRATEGY = 1  # Adaptive strategy:
    # STRATEGY = 0 ... refine elements until sqrt(THRESHOLD) times total
    #   error is processed. If more elements have similar errors, refine
    #   all to keep the mesh symmetric.
    # STRATEGY = 1 ... refine all elements whose error is larger
    #   than THRESHOLD times maximum element error.
    # STRATEGY = 2 ... refine all elements whose error is larger
    #   than THRESHOLD.
    # More adaptive strategies can be created in adapt_ortho_h1.cpp.
    ADAPT_TYPE = 0  # Type of automatic adaptivity:
    # ADAPT_TYPE = 0 ... adaptive hp-FEM (default),
    # ADAPT_TYPE = 1 ... adaptive h-FEM,
    # ADAPT_TYPE = 2 ... adaptive p-FEM.
    ISO_ONLY = False  # Isotropic refinement flag (concerns quadrilateral elements only).
    # ISO_ONLY = false ... anisotropic refinement of quad elements
    # is allowed (default),
    # ISO_ONLY = true ... only isotropic refinements of quad elements
    # are allowed.
    MESH_REGULARITY = -1  # Maximum allowed level of hanging nodes:
    # MESH_REGULARITY = -1 ... arbitrary level hangning nodes (default),
    # MESH_REGULARITY = 1 ... at most one-level hanging nodes,
    # MESH_REGULARITY = 2 ... at most two-level hanging nodes, etc.
    # Note that regular meshes are not supported, this is due to
    # their notoriously bad performance.
    MAX_ORDER = 10  # Maximum allowed element degree
    ERR_STOP = 0.5  # Stopping criterion for adaptivity (rel. error tolerance between the
    # fine mesh and coarse mesh solution in percent).
    NDOF_STOP = 40000  # Adaptivity process stops when the number of degrees of freedom grows over
    # this limit. This is mainly to prevent h-adaptivity to go on forever.

    # Problem constants
    E = 200e9  # Young modulus for steel: 200 GPa
    nu = 0.3  # Poisson ratio
    lamda = (E * nu) / ((1 + nu) * (1 - 2 * nu))
    mu = E / (2 * (1 + nu))

    # Load the mesh
    xmesh = Mesh()
    ymesh = Mesh()
    xmesh.load(get_bracket_mesh())

    # initial mesh refinements
    xmesh.refine_element(1)
    xmesh.refine_element(4)

    # Create initial mesh for the vertical displacement component,
    # identical to the mesh for the horizontal displacement
    # (bracket.mesh becomes a master mesh)
    ymesh.copy(xmesh)

    # Initialize the shapeset and the cache
    shapeset = H1Shapeset()
    xpss = PrecalcShapeset(shapeset)
    ypss = PrecalcShapeset(shapeset)

    # Create the x displacement space
    xdisp = H1Space(xmesh, shapeset)
    set_bc(xdisp)
    xdisp.set_uniform_order(P_INIT)

    # Create the x displacement space
    ydisp = H1Space(ymesh, shapeset)
    set_bc(ydisp)
    ydisp.set_uniform_order(P_INIT)

    # Enumerate basis functions
    ndofs = xdisp.assign_dofs()
    ydisp.assign_dofs(ndofs)

    # Initialize the weak formulation
    wf = WeakForm(2)
    set_wf_forms(wf)

    # Matrix solver
    solver = DummySolver()

    # adaptivity loop
    it = 1
    done = False
    cpu = 0.0

    x_sln_coarse = Solution()
    y_sln_coarse = Solution()

    x_sln_fine = Solution()
    y_sln_fine = Solution()

    # Calculating the number of degrees of freedom
    ndofs = xdisp.assign_dofs()
    ndofs += ydisp.assign_dofs(ndofs)

    # Solve the coarse mesh problem
    ls = LinSystem(wf, solver)
    ls.set_spaces(xdisp, ydisp)
    ls.set_pss(xpss, ypss)
    ls.assemble()
    ls.solve_system(x_sln_coarse, y_sln_coarse)

    # View the solution -- this can be slow; for illustration only
    stress_coarse = VonMisesFilter(x_sln_coarse, y_sln_coarse, mu, lamda)

    # Solve the fine mesh problem
    rs = RefSystem(ls)
    rs.assemble()
    rs.solve_system(x_sln_fine, y_sln_fine)

    # Calculate element errors and total error estimate
    hp = H1OrthoHP(xdisp, ydisp)
    set_hp_forms(hp)
    err_est = hp.calc_error_2(x_sln_coarse, y_sln_coarse, x_sln_fine, y_sln_fine) * 100

    # Show the fine solution - this is the final result
    stress_fine = VonMisesFilter(x_sln_fine, y_sln_fine, mu, lamda)
Example #14
0
#! /usr/bin/env python

from hermes2d import Mesh, H1Shapeset, PrecalcShapeset, H1Space, \
        BaseView

from hermes2d.forms import set_forms
from hermes2d.examples import get_example_mesh
domain_mesh = get_example_mesh()

mesh = Mesh()
mesh.load(domain_mesh)
mesh.refine_element(0)
shapeset = H1Shapeset()
pss = PrecalcShapeset(shapeset)

# create an H1 space
space = H1Space(mesh, shapeset)
space.set_uniform_order(5)
space.assign_dofs();

bview = BaseView()
bview.show(space)
bview.wait()