Exemplo n.º 1
0
def test_matlib():
    mats = {
        0: Material({
            'H1': 1.0,
            'K39': 1.0
        }, density=1.1),
        1: Material({
            'H1': 0.1,
            'O16': 1.0
        }, density=2.2),
        2: Material({'He4': 42.0}, density=3.3),
        3: Material({'Tm171': 171.0}, density=4.4),
    }
    m = gen_mesh(mats=mats)
    for i, ve in enumerate(mesh_iterate(m.mesh)):
        assert_is(m.mats[i], mats[i])
        assert_equal(
            m.mesh.tag_get_data(m.mesh.tag_get_handle('idx'), ve,
                                flat=True)[0], i)

    m.write_hdf5('test_matlib.h5m')
    shutil.copy('test_matlib.h5m', 'test_matlib2.h5m')
    m2 = Mesh(mesh='test_matlib2.h5m')  # MOAB fails to flush
    for i, mat, ve in m2:
        assert_equal(len(mat.comp), len(mats[i].comp))
        for key in mats[i].iterkeys():
            assert_equal(mat.comp[key], mats[i].comp[key])
        assert_equal(mat.density, mats[i].density)
        assert_equal(m2.idx[i], i)
Exemplo n.º 2
0
def cadis(adj_flux_mesh,
          adj_flux_tag,
          q_mesh,
          q_tag,
          ww_mesh,
          ww_tag,
          q_bias_mesh,
          q_bias_tag,
          beta=5):
    """This function reads PyNE Mesh objects tagged with adjoint fluxes and
    unbiased source densities and outputs PyNE Meshes of weight window lower
    bounds and biased source densities as computed by the Consistant
    Adjoint-Driven Importance Sampling (CADIS) method [1]. Note that values can
    be stored on the same Mesh object, all different Mesh objects, or any
    combination in between. Meshes can be structured or unstructured.
    Note that this function is suitable for Forward Weighted (FW) CADIS as well,
    the only difference being the adjoint source used for the estimation of the
    adjoint flux.

    [1] Haghighat, A. and Wagner, J. C., "Monte Carlo Variance Reduction with
        Deterministic Importance Functions," Progress in Nuclear Energy,
        Vol. 42, No. 1, pp. 25-53, 2003.

    Parameters
    ----------
    adj_flux_mesh : PyNE Mesh object
        The mesh containing the adjoint fluxes.
    adj_flux_tag : string
        The name of the adjoint flux tag on adj_mesh.
    q_mesh : PyNE Mesh object
        The mesh containing the unbiased source density.
    q_tag : string
        The name of the source density tag on q_mesh.
    ww_mesh : PyNE Mesh object
        The mesh to store the output weight window mesh.
    ww_tag : string
        Name of the tag to store output weight window values on ww_mesh.
    q_bias_mesh : PyNE Mesh object
        The mesh to store the output biased source density mesh.
    q_bias_tag : PyNE Mesh object
        Name of the tag to store output weight window values on q_bias_mesh.
    beta : float
        The ratio of the weight window upper bound to the weight window lower
        bound. The default value is 5: the value used in MCNP.
    """

    # find number of energy groups
    e_groups = adj_flux_mesh.get_tag(adj_flux_tag)[list(
        mesh_iterate(adj_flux_mesh.mesh))[0]]
    e_groups = np.atleast_1d(e_groups)
    num_e_groups = len(e_groups)

    # verify source (q) mesh has the same number of energy groups
    q_e_groups = q_mesh.get_tag(q_tag)[list(mesh_iterate(q_mesh.mesh))[0]]
    q_e_groups = np.atleast_1d(q_e_groups)
    num_q_e_groups = len(q_e_groups)

    if num_q_e_groups != num_e_groups:
        raise TypeError("{0} on {1} and {2} on {3} "
                        "must be of the same dimension".format(
                            adj_flux_mesh, adj_flux_tag, q_mesh, q_tag))

    # create volume element (ve) iterators
    adj_ves = mesh_iterate(adj_flux_mesh.mesh)
    q_ves = mesh_iterate(q_mesh.mesh)

    # calculate total source strength
    q_tot = 0
    for q_ve in q_ves:
        q_tot += np.sum(q_mesh.get_tag(q_tag)[q_ve]) \
            * q_mesh.elem_volume(q_ve)

    q_ves.reset()

    # calculate the total response per source particle (R)
    R = 0
    for adj_ve, q_ve in zip(adj_ves, q_ves):
        adj_flux = adj_flux_mesh.get_tag(adj_flux_tag)[adj_ve]
        adj_flux = np.atleast_1d(adj_flux)
        q = q_mesh.get_tag(q_tag)[q_ve]
        q = np.atleast_1d(q)

        vol = adj_flux_mesh.elem_volume(adj_ve)
        for i in range(0, num_e_groups):
            R += adj_flux[i] * q[i] * vol / q_tot

    # generate weight windows and biased source densities using R
    ww_mesh.tag(ww_tag,
                np.zeros(num_e_groups, dtype=float),
                'nat_mesh',
                size=num_e_groups,
                dtype=float)
    tag_ww = ww_mesh.get_tag(ww_tag)
    ww_ves = mesh_iterate(ww_mesh.mesh)
    q_bias_mesh.tag(q_bias_tag,
                    np.zeros(num_e_groups, dtype=float),
                    'nat_mesh',
                    size=num_e_groups,
                    dtype=float)
    tag_q_bias = q_bias_mesh.get_tag(q_bias_tag)
    q_bias_ves = mesh_iterate(q_bias_mesh.mesh)
    # reset previously created iterators
    q_ves.reset()
    adj_ves.reset()

    for adj_ve, q_ve, ww_ve, q_bias_ve in zip(adj_ves, q_ves, ww_ves,
                                              q_bias_ves):
        adj_flux = adj_flux_mesh.get_tag(adj_flux_tag)[adj_ve]
        adj_flux = np.atleast_1d(adj_flux)
        q = q_mesh.get_tag(q_tag)[q_ve]
        q = np.atleast_1d(q)

        tag_q_bias[q_bias_ve] = [
            adj_flux[i] * q[i] / q_tot / R for i in range(num_e_groups)
        ]

        tag_ww[ww_ve] = [
            R / (adj_flux[i] * (beta + 1.) / 2.) if adj_flux[i] != 0.0 else 0.0
            for i in range(num_e_groups)
        ]
Exemplo n.º 3
0
def mesh_to_fluxin(
    flux_mesh,
    flux_tag,
    fluxin="fluxin.out",
    reverse=False,
    sub_voxel=False,
    cell_fracs=None,
    cell_mats=None,
    print_progress=True,
):
    """This function creates an ALARA fluxin file from fluxes tagged on a PyNE
    Mesh object. Fluxes are printed in the order of the flux_mesh.__iter__().

    Parameters
    ----------
    flux_mesh : PyNE Mesh object
        Contains the mesh with fluxes tagged on each volume element.
    flux_tag : string
        The name of the tag of the flux mesh. Flux values for different energy
        groups are assumed to be represented as vector tags.
    fluxin : string
        The name of the ALARA fluxin file to be output.
    reverse : bool
        If true, fluxes will be printed in the reverse order as they appear in
        the flux vector tagged on the mesh.
    sub_voxel: bool, optional
        If true, sub-voxel r2s work flow will be sued. Flux of a voxel will
        be duplicated c times. Where c is the cell numbers of that voxel.
    cell_fracs : structured array, optional
        The output from dagmc.discretize_geom(). A sorted, one dimensional
        array, each entry containing the following fields:

            :idx: int
                The volume element index.
            :cell: int
                The geometry cell number.
            :vol_frac: float
                The volume fraction of the cell withing the mesh ve.
            :rel_error: float
                The relative error associated with the volume fraction.

        The array must be sorted with respect to both idx and cell, with
        cell changing fastest.
    cell_mats : dict, optional
        Maps geometry cell numbers to PyNE Material objects.
        The cell_fracs and cell_mats are used only when sub_voxel=True.
        If sub_voxel=False, neither cell_fracs nor cell_mats will be used.
    print_progress : bool
        Print the progress with progress bar. Set to False to turn off progress.
    """

    tag_flux = flux_mesh.get_tag(flux_tag)

    # find number of e_groups
    e_groups = tag_flux[list(mesh_iterate(flux_mesh.mesh))[0]]
    e_groups = np.atleast_1d(e_groups)
    num_e_groups = len(e_groups)

    # write flux data block by block
    with open(fluxin, "w") as f:
        if not sub_voxel:
            bar = IfBar(
                "Writing alara fluxin",
                max=len(flux_mesh),
                suffix="%(percent).1f%% - %(eta)ds",
                show=print_progress,
            )
            for i, mat, ve in flux_mesh:
                f.write(_output_flux_block(ve, tag_flux, reverse))
                bar.next()
            bar.finish()
        else:
            ves = list(flux_mesh.iter_ve())
            bar = IfBar(
                "Writing alara fluxin",
                max=len(cell_fracs),
                suffix="%(percent).1f%% - %(eta)ds",
                show=print_progress,
            )
            for i, row in enumerate(cell_fracs):
                if len(cell_mats[row["cell"]].comp) != 0:
                    f.write(
                        _output_flux_block(ves[row["idx"]], tag_flux, reverse))
                bar.next()
            bar.finish()
Exemplo n.º 4
0
def mesh_to_fluxin(flux_mesh,
                   flux_tag,
                   fluxin="fluxin.out",
                   reverse=False,
                   sub_voxel=False,
                   cell_fracs=None,
                   cell_mats=None):
    """This function creates an ALARA fluxin file from fluxes tagged on a PyNE
    Mesh object. Fluxes are printed in the order of the flux_mesh.__iter__().

    Parameters
    ----------
    flux_mesh : PyNE Mesh object
        Contains the mesh with fluxes tagged on each volume element.
    flux_tag : string
        The name of the tag of the flux mesh. Flux values for different energy
        groups are assumed to be represented as vector tags.
    fluxin : string
        The name of the ALARA fluxin file to be output.
    reverse : bool
        If true, fluxes will be printed in the reverse order as they appear in
        the flux vector tagged on the mesh.
    sub_voxel: bool, optional
        If true, sub-voxel r2s work flow will be sued. Flux of a voxel will
        be duplicated c times. Where c is the cell numbers of that voxel.
    cell_fracs : structured array, optional
        The output from dagmc.discretize_geom(). A sorted, one dimensional
        array, each entry containing the following fields:

            :idx: int
                The volume element index.
            :cell: int
                The geometry cell number.
            :vol_frac: float
                The volume fraction of the cell withing the mesh ve.
            :rel_error: float
                The relative error associated with the volume fraction.

        The array must be sorted with respect to both idx and cell, with
        cell changing fastest.
    cell_mats : dict, optional
        Maps geometry cell numbers to PyNE Material objects.

        The cell_fracs and cell_mats are used only when sub_voxel=True.
        If sub_voxel=False, neither cell_fracs nor cell_mats will be used.

    """
    tag_flux = flux_mesh.get_tag(flux_tag)

    # find number of e_groups
    e_groups = tag_flux[list(mesh_iterate(flux_mesh.mesh))[0]]
    e_groups = np.atleast_1d(e_groups)
    num_e_groups = len(e_groups)

    # Establish for loop bounds based on if forward or backward printing
    # is requested
    if not reverse:
        start = 0
        stop = num_e_groups
        direction = 1
    else:
        start = num_e_groups - 1
        stop = -1
        direction = -1

    output = u""
    if not sub_voxel:
        for i, mat, ve in flux_mesh:
            # print flux data to file
            output = _output_flux(ve, tag_flux, output, start, stop, direction)
    else:
        ves = list(flux_mesh.iter_ve())
        for row in cell_fracs:
            if len(cell_mats[row['cell']].comp) != 0:
                output = _output_flux(ves[row['idx']], tag_flux, output, start,
                                      stop, direction)

    with open(fluxin, "w") as f:
        f.write(output)