Source code for sfepy.discrete.common.mappings

"""
Reference-physical domain mappings.
"""
import numpy as nm

from sfepy.base.base import Struct

[docs]class PhysicalQPs(Struct): """ Physical quadrature points in a region. """ def __init__(self, num=0): Struct.__init__(self, num=num, shape=(0, 0, 0)) self.values = nm.empty(self.shape, dtype=nm.float64)
[docs] def get_shape(self, rshape): """ Get shape from raveled shape. """ n_qp = self.shape[1] if n_qp > 0: if (rshape[0] / n_qp) * n_qp != rshape[0]: raise ValueError('incompatible shapes! (n_qp: %d, %s)' % (n_qp, rshape)) shape = (rshape[0] // n_qp, n_qp) + rshape[1:] else: shape = (rshape[0], 0, 0, 0) return shape
[docs]class Mapping(Struct): """ Base class for mappings. """
[docs] @staticmethod def from_args(region, kind='v'): """ Create mapping from reference to physical entities in a given region, given the integration kind ('v' or 's'). This mapping can be used to compute the physical quadrature points. Parameters ---------- region : Region instance The region defining the entities. kind : 'v' or 's' The kind of the entities: 'v' - cells, 's' - facets. Returns ------- mapping : VolumeMapping or SurfaceMapping instance The requested mapping. """ from sfepy.discrete.fem.domain import FEDomain from sfepy.discrete.iga.domain import IGDomain if isinstance(region.domain, FEDomain): import sfepy.discrete.fem.mappings as mm coors = region.domain.get_mesh_coors() if kind == 's': coors = coors[region.vertices] conn, gel = region.domain.get_conn(ret_gel=True) if kind == 'v': cells = region.get_cells() mapping = mm.VolumeMapping(coors, conn[cells], gel=gel) elif kind == 's': from sfepy.discrete.fem.fe_surface import FESurface aux = FESurface('aux', region, gel.get_surface_entities(), conn) mapping = mm.SurfaceMapping(coors, aux.leconn, gel=gel.surface_facet) elif isinstance(region.domain, IGDomain): import sfepy.discrete.iga.mappings as mm mapping = mm.IGMapping(region.domain, region.cells) else: raise ValueError('unknown domain class! (%s)' % type(region.domain)) return mapping
[docs]def get_physical_qps(region, integral, map_kind=None): """ Get physical quadrature points corresponding to the given region and integral. """ phys_qps = PhysicalQPs() if map_kind is None: map_kind = 'v' if region.can_cells else 's' gmap = Mapping.from_args(region, map_kind) gel = gmap.get_geometry() qp_coors, _ = integral.get_qp(gel.name) qps = gmap.get_physical_qps(qp_coors) n_el, n_qp = qps.shape[0], qps.shape[1] phys_qps.num = n_el * n_qp phys_qps.shape = qps.shape qps.shape = (phys_qps.num, qps.shape[2]) phys_qps.values = qps return phys_qps
[docs]def get_mapping_data(name, field, integral, region=None, integration='volume'): """ General helper function for accessing reference mapping data. Get data attribute `name` from reference mapping corresponding to `field` in `region` in quadrature points of the given `integral` and `integration` type. Parameters ---------- name : str The reference mapping attribute name. field : Field instance The field defining the reference mapping. integral : Integral instance The integral defining quadrature points. region : Region instance, optional If given, use the given region instead of `field` region. integration : one of ('volume', 'surface', 'surface_extra') The integration type. Returns ------- data : array The required data merged for all element groups. Notes ----- Assumes the same element geometry in all element groups of the field! """ data = None if region is None: region = field.region geo, _ = field.get_mapping(region, integral, integration) data = getattr(geo, name) return data
[docs]def get_jacobian(field, integral, region=None, integration='volume'): """ Get the jacobian of reference mapping corresponding to `field`. Parameters ---------- field : Field instance The field defining the reference mapping. integral : Integral instance The integral defining quadrature points. region : Region instance, optional If given, use the given region instead of `field` region. integration : one of ('volume', 'surface', 'surface_extra') The integration type. Returns ------- jac : array The jacobian merged for all element groups. See Also -------- get_mapping_data() Notes ----- Assumes the same element geometry in all element groups of the field! """ jac = get_mapping_data('det', field, integral, region=region, integration=integration) return jac
[docs]def get_normals(field, integral, region): """ Get the normals of element faces in `region`. Parameters ---------- field : Field instance The field defining the reference mapping. integral : Integral instance The integral defining quadrature points. region : Region instance The given of the element faces. Returns ------- normals : array The normals merged for all element groups. See Also -------- get_mapping_data() Notes ----- Assumes the same element geometry in all element groups of the field! """ normals = get_mapping_data('normal', field, integral, region=region, integration='surface') return normals