def get_edge_image(self,item):
if self.edgeMap.has_key(item):
return self.edgeMap[item]
elif len(item.Composition)>1:
iterator = item.iterComposingMorphisms()
morphi = self.edgeMap[next(iterator)]
if isMorphismZero(morphi):
return GiveZeroMorphism(self.nodeMap[item.source],self.nodeMap[item.target]).equivalenceClass()
for atomic in iterator: #inefficient #it just got even more inefficient
atomicimage = self.edgeMap[atomic]
if isMorphismZero(atomicimage):
return GiveZeroMorphism(self.nodeMap[item.source],self.nodeMap[item.target]).equivalenceClass()
morphi = morphi.compose(atomicimage)
return morphi
elif isinstance(item,Identity):
return getIdentity(self.edgeMap[item.source])
def implement(self):
'''carry out the pushout of the Extension Meta-Diagram'''
#Extend hom to a lift of the extension to the main Diagram
lift = self.hom*self.rule.partialInverse #inefficient
for obj in self.rule.newObjects:
try:
names=[]
for s in obj.namescheme[1]:
obj_item = self.charDiag[s]
if isinstance(obj_item,Object):
names.append(self.hom[self.charDiag[s]].name)
else:#morphism
names.append(self.hom.get_edge_image(self.charDiag[s]).representative.name)
newname=obj.namescheme[0].format(*names)
newobj = Object(self.mainDiag,newname) #try naming according to scheme
except:
try:
newobj=Object(self.mainDiag,self.mainDiag.giveName(mode=newname)) #append a number to name if this failed
except:
newobj = Object(self.mainDiag) #give a generic name if everything fails
latexlist=[]
try:
for s in obj.latexscheme[1]:
try:
try:
latexlist.append(self.hom[self.charDiag[s]].latex)
except:
latexlist.append(self.hom[self.charDiag[s]].name)
except:
try:
latexlist.append(self.hom.edgeMap[self.charDiag.Morphisms[s]].latex)
except:
latexlist.append(self.hom.edgeMap[self.charDiag.Morphisms[s]].name)
newobj.latex=obj.latexscheme[0].format(*latexlist) #set LaTeX display string
except:
newobj.latex=newobj.name
lift.set_node_image(obj,newobj)
for morphi in self.rule.newMorphisms:
source = lift[morphi.source]
target = lift[morphi.target]
if isinstance(morphi,Identity):
newmorphi = getIdentity(source)
elif isMorphismZero(morphi):
newmorphi = GiveZeroMorphism(source,target)
else:
newmorphi = Morphism(source,target) #do not implement nameschemes for morphisms for now
latexlist=[]
try:
for s in morphi.latexscheme[1]:
try:
try:
latexlist.append(self.hom[self.charDiag[s]].latex)
except:
latexlist.append(self.hom[self.charDiag[s]].name)
except:
try:
latexlist.append(self.hom.edgeMap[self.charDiag[s]].representative.latex)
except:
latexlist.append(self.hom.edgeMap[self.charDiag[s]].representative.name)
newmorphi.latex=morphi.latexscheme[0].format(*latexlist) #set LaTeX display string
except:
pass
lift.set_edge_image(morphi,self.mainDiag.CommutativityQuotient.get_edge_image(newmorphi))
#compose characteristic homomorphism of property with lift to get
#characteristic homomorphism in the extended main Diagram
#for commutativity classes, just choose an arbitrary section
for prop in self.rule.newProperties:
prop.push_forward(lift)
def get_edge_image(self,item):
res = Homomorphism.get_edge_image(self,item)
if res is not None:
return res
if isinstance(item,Identity):
return getIdentity(self.edgeMap[item.source])
