def _build_endmap(self, consolidate=False):
"""
Builds the map on ends for graph_map. Called when Core is initialized.
"""
alph = self._graph_map.domain()._alphabet
inv_alph = self._inv_graph_map.domain()._alphabet
FA = FreeGroup(alph)
FB = FreeGroup(inv_alph)
for x in self._graph_map.domain().edge_labels():
X = alph.inverse_letter(x)
self._signed_ends[x] = []
self._signed_ends[X] = []
for x in self._inv_graph_map.domain().edge_labels():
X = inv_alph.inverse_letter(x)
inv_image_x = self._inv_graph_map(x)
vp = '' # vanishing path
for a in inv_image_x:
A = alph.inverse_letter(a)
if vp == '' or vp[
-1] != X: # coming from + side, no cancellation
self._signed_ends[a].append(vp + x)
else: # coming from - side, cancels x
self._signed_ends[a].append('-' + vp) # - + vp #
# add to vanishing path
vp = str(FB.reduced_product(str(self._graph_map(A)), vp))
# repeat for inverse, we've added to the vanishing path because we are
# coming from the other side
if vp == '' or vp[
-1] != X: # coming from - side, no cancellation
self._signed_ends[A].append('-' + vp + x) # - + vp + x
else: # coming from + side, cancels x
self._signed_ends[A].append(vp)
if consolidate:
for a in self._signed_ends.keys():
removed_end = True
N = 2 * inv_alph.cardinality(
) # should take into account the actual vertex...
while removed_end:
removed_end = False
prefix = []
for e in self._signed_ends[a]:
prefix.append(e[:-1])
prefix_counts = dict(
(p, prefix.count(p)) for p in set(prefix))
for p in prefix_counts.keys():
p_opp = p[1:] if p[:1] == '-' else '-' + p
removed_ends = []
tails = []
if prefix_counts[p] == N - 1:
removed_end = True
for e in self._signed_ends[a]:
if e[:-1] == p:
removed_ends.append(e)
tails.append(e[-1:])
if p == '' or p == '-':
for aa in inv_alph:
if aa not in tails:
self._signed_ends[a].append(p_opp + aa)
else:
self._signed_ends[a].append(p)
for e in removed_ends:
self._signed_ends[a].remove(e)
if prefix_counts[
p] == N - 2 and p_opp in self._signed_ends[a]:
removed_end = True
for e in self._signed_ends[a]:
if e[:-1] == p:
removed_ends.append(e)
tails.append(e[-1:])
tails.append(inv_alph.inverse_letter(p[-1:]))
for aa in inv_alph:
if aa not in tails:
self._signed_ends[a].append(p_opp + aa)
for e in removed_ends:
self._signed_ends[a].remove(e)
self._signed_ends[a].remove(p_opp)
def _build_endmap(self,consolidate=False):
"""
Builds the map on ends for graph_map. Called when Core is initialized.
"""
alph=self._graph_map.domain()._alphabet
inv_alph=self._inv_graph_map.domain()._alphabet
FA=FreeGroup(alph)
FB=FreeGroup(inv_alph)
for x in self._graph_map.domain().edge_labels():
X=alph.inverse_letter(x)
self._signed_ends[x]=[]
self._signed_ends[X]=[]
for x in self._inv_graph_map.domain().edge_labels():
X=inv_alph.inverse_letter(x)
inv_image_x = self._inv_graph_map(x)
vp='' # vanishing path
for a in inv_image_x:
A=alph.inverse_letter(a)
if vp=='' or vp[-1]!=X: # coming from + side, no cancellation
self._signed_ends[a].append(vp + x)
else: # coming from - side, cancels x
self._signed_ends[a].append('-' + vp) # - + vp #
# add to vanishing path
vp=str(FB.reduced_product(str(self._graph_map(A)),vp))
# repeat for inverse, we've added to the vanishing path because we are
# coming from the other side
if vp=='' or vp[-1]!=X: # coming from - side, no cancellation
self._signed_ends[A].append('-' + vp + x) # - + vp + x
else: # coming from + side, cancels x
self._signed_ends[A].append(vp)
if consolidate:
for a in self._signed_ends.keys():
removed_end=True
N=2*inv_alph.cardinality() # should take into account the actual vertex...
while removed_end:
removed_end=False
prefix=[]
for e in self._signed_ends[a]:
prefix.append(e[:-1])
prefix_counts=dict((p,prefix.count(p)) for p in set(prefix))
for p in prefix_counts.keys():
p_opp = p[1:] if p[:1]=='-' else '-'+p
removed_ends=[]
tails=[]
if prefix_counts[p]==N-1:
removed_end=True
for e in self._signed_ends[a]:
if e[:-1]==p:
removed_ends.append(e)
tails.append(e[-1:])
if p=='' or p=='-':
for aa in inv_alph:
if aa not in tails: self._signed_ends[a].append(p_opp+aa)
else: self._signed_ends[a].append(p)
for e in removed_ends: self._signed_ends[a].remove(e)
if prefix_counts[p]==N-2 and p_opp in self._signed_ends[a]:
removed_end=True
for e in self._signed_ends[a]:
if e[:-1]==p:
removed_ends.append(e)
tails.append(e[-1:])
tails.append(inv_alph.inverse_letter(p[-1:]))
for aa in inv_alph:
if aa not in tails: self._signed_ends[a].append(p_opp+aa)
for e in removed_ends: self._signed_ends[a].remove(e)
self._signed_ends[a].remove(p_opp)
