def compute_cohomology(self):
cohomology = ModVectorSpace([])
##### Tweak to check dimension before working
if not self.get_cohomology_dim():
self.cohomology = cohomology
self.cohomology_flag = True
return
#####
index_list = self.get_kernel().get_basis()[:]
basis_list = []
for ker_element in index_list:
if not self.in_cohomology_subspace(basis_list, ker_element):
basis_list.append(ker_element)
cohomology.add_basis_element(basis_list)
self.cohomology = cohomology
if (self.get_B().col_count - self.get_B().get_rank()
- self.get_A().get_rank() != len(cohomology.get_basis())):
print "A"
print self.get_A()
print "B"
print self.get_B()
print "rank A"
print self.get_A().get_rank()
print "nullity B"
print self.get_B().col_count - self.get_B().get_rank()
print "basis for cohomology"
for thing in cohomology.get_basis():
print thing
raise TypeError("cohomology basis computation incorrect!")
self.cohomology_flag = True
def compute_image(self):
image = ModVectorSpace([])
for row in self.get_A().get_rref():
if not row.is_zero():
index = row.get_leading_index()
image.add_basis_element([ self.get_A().get_column(index) ])
self.image = image
self.image_flag = True
def __init__(self, B, A):
self.B = B
self.A = A
self.kernel = None
self.kernel_flag = False
self.image = None
self.image_flag = False
self.cohomology = None
self.cohomology_flag = False
self.product = ModVectorSpace([])
# if self.A.rows == []:
# self.A = ModMatrix.null(self.B.get_size()[1], 1)
# elif self.B.rows == []:
# raise TypeError
if self.B.get_size()[1] != self.A.get_size()[0]:
raise TypeError("wrong sizes B: " + str(self.B) + "A: " +
str(self.A))
self.extended_ker_basis = None
self.extended_ker_basis_flag = False
def get_kernel(self):
if not self.get_kernel_flag():
self.kernel = ModVectorSpace(self.get_B().get_kernel_vout())
self.kernel_flag = True
return self.kernel
