def BTdot(self, uin):
"""Compute B^T.uin as a np.array
uin must be a np.array"""
isarray(uin)
u = Function(self.V)
out = u.vector()
for ii, bb in enumerate(self.B):
out += bb*uin[ii]
return out.array()
def apply_noise(self, uin):
"""Apply Gaussian noise to np.array of data.
noisepercent = 0.02 => 2% noise level, i.e.,
|| u - ud || / || ud || = || noise || / || ud || = 0.02"""
isarray(uin)
noisevect = randn(len(uin))
# Get norm of entire random vector:
if self.mycomm == None: normrand = norm(noisevect)
else:
normrand = sqrt(MPI.sum(self.mycomm, norm(noisevect)**2))
noisevect /= normrand
# Get norm of entire vector ud (not just local part):
if self.mycomm == None: normud = norm(uin)
else:
normud = sqrt(MPI.sum(self.mycomm, norm(uin)**2))
noisevect *= self.noisepercent * normud
objnoise_glob = (self.noisepercent * normud)**2
UDnoise = uin + noisevect
return UDnoise, objnoise_glob
def BTdotvec(self, uin, outvect):
""" Compute B^T.uin """
isarray(uin)
outvect.zero()
for ii, bb in enumerate(self.B):
outvect += bb*uin[ii]