def _build_orientation_map(n_fp):
"""
The keys are binary masks of the lexicographical ordering of facet
vertices. A bit i set to one means `v[i] < v[i+1]`.
The values are `[original_order, permutation, orientation]`, where
`permutation` can be used to sort facet vertices lexicographically,
and `orientation` is the order of the first vertex + 1 times the
sign. Hence `permuted_facet = facet[permutation]`.
"""
indices = range(n_fp)
cmps = [(i1, i2) for i2 in indices for i1 in indices[:i2]]
powers = [2**ii for ii in range(len(cmps))]
ori_map = {}
for indx in permutations(indices):
key = 0
sign = 1
for ip, power in enumerate(powers):
i1, i2 = cmps[ip]
less = (indx[i1] < indx[i2])
key += power * less
if not less:
sign *= -1
isort = nm.argsort(indx)
ori_map[key] = [indx, isort, sign * (indx[0] + 1)]
return ori_map, cmps, powers
def build_orientation_map(n_fp):
"""
The keys are binary masks of the lexicographical ordering of facet
vertices. A bit i set to one means `v[i] < v[i+1]`.
The values are `[original_order, permutation]`, where `permutation` can be
used to sort facet vertices lexicographically. Hence `permuted_facet =
facet[permutation]`.
"""
from sfepy.linalg import permutations
indices = list(range(n_fp))
cmps = [(i1, i2) for i2 in indices for i1 in indices[:i2]]
powers = [2**ii for ii in range(len(cmps))]
ori_map = {}
for indx in permutations(indices):
key = 0
sign = 1
for ip, power in enumerate(powers):
i1, i2 = cmps[ip]
less = (indx[i1] < indx[i2])
key += power * less
if not less:
sign *= -1
isort = nm.argsort(indx)
ori_map[key] = [indx, isort]
return ori_map, cmps, powers
def _build_orientation_map(n_fp):
"""
The keys are binary masks of the lexicographical ordering of facet
vertices. A bit i set to one means `v[i] < v[i+1]`.
The values are `[original_order, permutation, orientation]`, where
`permutation` can be used to sort facet vertices lexicographically,
and `orientation` is the order of the first vertex + 1 times the
sign. Hence `permuted_facet = facet[permutation]`.
"""
indices = range(n_fp)
cmps = [(i1, i2) for i2 in indices for i1 in indices[:i2]]
powers = [2 ** ii for ii in range(len(cmps))]
ori_map = {}
for indx in permutations(indices):
key = 0
sign = 1
for ip, power in enumerate(powers):
i1, i2 = cmps[ip]
less = indx[i1] < indx[i2]
key += power * less
if not less:
sign *= -1
isort = nm.argsort(indx)
ori_map[key] = [indx, isort, sign * (indx[0] + 1)]
return ori_map, cmps, powers