def canonize_and_add_monomials(self, monomials, lower_bound=None):
inadmissibles = KeyOrderedDict()
def push_inadmissible(inad):
inadmissibles.toggle(RevlexBasisMonomial(*inad), 1)
for mon in monomials:
if mon.admissible():
self._add_admissible_monomial(mon)
else:
push_inadmissible(mon)
while inadmissibles:
mon, _ = inadmissibles.remove_max()
if lower_bound is not None and leading_integer_upper_bound(mon) < lower_bound[0]:
continue
for rep in _adem_relation(mon):
if rep.admissible():
if lower_bound is None or rep >= lower_bound:
self._add_admissible_monomial(rep)
else:
push_inadmissible(rep)
def __init__(self, monomials, lower_bound=None):
self._admissibles = KeyOrderedDict()
self.canonize_and_add_monomials(monomials, lower_bound=lower_bound)
class AdmissibleTerm(object):
def __init__(self, monomials, lower_bound=None):
self._admissibles = KeyOrderedDict()
self.canonize_and_add_monomials(monomials, lower_bound=lower_bound)
def __str__(self):
s = ' + '.join(map(str, self._admissibles))
return s if s else '0'
def _add_admissible_monomial(self, monomial):
self._admissibles.toggle(LexBasisMonomial(*monomial), 1)
def __len__(self):
return len(self._admissibles)
def __iter__(self):
return iter(self._admissibles)
def __eq__(self, other):
return self._admissibles == other._admissibles
def __bool__(self):
return bool(self._admissibles)
is_zero = __bool__
def leading_term(self):
if self._admissibles:
k, _ = self._admissibles.peek_max()
return k
else:
raise IndexError('Attempt to examine leading term in zero expression')
# this obviously leaves room for improvement
def canonize_and_add_monomials(self, monomials, lower_bound=None):
inadmissibles = KeyOrderedDict()
def push_inadmissible(inad):
inadmissibles.toggle(RevlexBasisMonomial(*inad), 1)
for mon in monomials:
if mon.admissible():
self._add_admissible_monomial(mon)
else:
push_inadmissible(mon)
while inadmissibles:
mon, _ = inadmissibles.remove_max()
if lower_bound is not None and leading_integer_upper_bound(mon) < lower_bound[0]:
continue
for rep in _adem_relation(mon):
if rep.admissible():
if lower_bound is None or rep >= lower_bound:
self._add_admissible_monomial(rep)
else:
push_inadmissible(rep)
def differential(self, lower_bound=None):
seq = chain.from_iterable(map(_differential, iter(self)))
return AdmissibleTerm(seq, lower_bound=lower_bound)
def __add__(self, other):
new_at = AdmissibleTerm([])
new_at._admissibles = self._admissibles.sym_diff(other._admissibles)
return new_at
def __iadd__(self, other):
self._admissibles = self._admissibles.sym_diff(other._admissibles)
return self
def __mul__(self, other):
terms = (x * y for x, y in product(self, other))
return AdmissibleTerm(terms)
def copy(self):
new_at = AdmissibleTerm([])
new_at._admissibles = self._admissibles.copy()
return new_at
