def _testme():
from scipy.sparse import csc_matrix
from numpy import array
from scipy.linsolve import spdiags, spsolve, use_solver
print "Inverting a sparse linear system:"
print "The sparse matrix (constructed from diagonals):"
a = spdiags([[1, 2, 3, 4, 5], [6, 5, 8, 9, 10]], [0, 1], 5, 5)
b = array([1, 2, 3, 4, 5])
print "Solve: single precision complex:"
use_solver( useUmfpack = False )
a = a.astype('F')
x = spsolve(a, b)
print x
print "Error: ", a*x-b
print "Solve: double precision complex:"
use_solver( useUmfpack = True )
a = a.astype('D')
x = spsolve(a, b)
print x
print "Error: ", a*x-b
print "Solve: double precision:"
a = a.astype('d')
x = spsolve(a, b)
print x
print "Error: ", a*x-b
print "Solve: single precision:"
use_solver( useUmfpack = False )
a = a.astype('f')
x = spsolve(a, b.astype('f'))
print x
print "Error: ", a*x-b
def levenberg_iteration(z, z_p, z_l, x_p, x_l, f_p, f_l, C, lamb):
"""
"""
x = build_zx(x_p, x_l)
J = build_jacobian(z, x_p, x_l, f_p, f_l)
#J = build_jacobian_numeric(z, x_p,x_l,f_p,f_l)
Jsp = J.tocsr()
Csp = C.tocsr()
alpha = Jsp.T.dot(Csp.dot(Jsp))
fy_i = []
for i, f in zip(z_p, f_p):
l1 = matrix([i[0], i[1], i[2]]).T
l2 = f[0](x_p[f[1]], x_p[f[2]])
result = l1 - l2
fy_i += result.T.tolist()[0]
for i, f in zip(z_l, f_l):
l1 = matrix([[i[0]], [i[1]]])
l2 = f[0](x_p[f[1]], x_l[f[2]])
result = l1 - l2
fy_i += result.T.tolist()[0]
fy_i = array(fy_i, dtype=float64).T
beta = Jsp.T.dot(Csp.dot(fy_i))
# Augmented alpha
alpha.setdiag(sparse.extract_diagonal(alpha) * (1 + lamb))
#### sparse solver
return linsolve.spsolve(alpha, beta)
def check_solve_sparse_rhs(self):
"""Solve with UMFPACK: double precision, sparse rhs"""
linsolve.use_solver( useUmfpack = True )
a = self.a.astype('d')
b = csc_matrix( self.b )
x = linsolve.spsolve(a, b)
#print x
#print "Error: ", a*x-b
assert_array_almost_equal(a*x, self.b)
def check_solve_umfpack(self):
"""Solve with UMFPACK: double precision"""
linsolve.use_solver( useUmfpack = True )
a = self.a.astype('d')
b = self.b
x = linsolve.spsolve(a, b)
#print x
#print "Error: ", a*x-b
assert_array_almost_equal(a*x, b)
def check_solve_without_umfpack(self):
"""Solve: single precision"""
linsolve.use_solver( useUmfpack = False )
a = self.a.astype('f')
b = self.b
x = linsolve.spsolve(a, b.astype('f'))
#print x
#print "Error: ", a*x-b
assert_array_almost_equal(a*x, b)
def GetEigSparse(D, e1, e2, w):
w -= dot(w, e1) * e1 / dot(e1, e1)
w -= dot(w, e2) * e2 / dot(e2, e2)
for i in range(3):
w = linsolve.spsolve(D, w)
w -= dot(w, e1) * e1 / dot(e1, e1)
w -= dot(w, e2) * e2 / dot(e2, e2)
w /= dot(w, w)**.5
return w
def GetEigSparse(D, e1, e2, w):
w -= dot(w,e1) * e1 / dot(e1,e1)
w -= dot(w,e2) * e2 / dot(e2,e2)
for i in range(3):
w = linsolve.spsolve(D,w)
w -= dot(w,e1) * e1 / dot(e1,e1)
w -= dot(w,e2) * e2 / dot(e2,e2)
w /= dot(w,w)**.5
return w
def solve(self, rhs):
ij = vstack((self.x_l,self.y_l))
#print "ij", ij
#print "data ", self.data_l
mtx = sparse.coo_matrix((self.data_l,ij))
mtx.tocsr()
ts_solve_s = time()
u_vct = linsolve.spsolve( mtx, rhs )
ts_solve_e = time()
dif_solve = ts_solve_e - ts_solve_s
print "Sparse Solve: %8.2f sec" %dif_solve
return u_vct
def eval( self, e = None ):
if not self.sync_resp_tracing:
self.rtrace_mngr.start_timer()
adap = self.adap
tstepper = self.ts
self.setup()
self.ls_counter = 0
# Measure computation time
self.eval_timer.reset()
# Register the list of variables requrired by the adaptive
# strategy in the time stepper to include their evaluation in
# the corrector-predictor evaluation ts.extend_output_list(
# adap.get_indicator_list() )
#
while self.t_n1 <= self.T.max and not self.user_wants_abort:
self.iter_timer.reset()
if LOGGING_ON:
log.info( '===================================')
log.info('time t_n1 = %f',self.t_n1)
self.ls_counter += 1
self.report_load_step()
self.k = 0
step_flag = 'predictor'
while self.k < self.KMAX:
self.report_iteration()
# Extract the matrix representation of the time t_n1
# stepper for the given time and control variable u
#
self.crpr_timer.reset()
self.K, self.F_int, self.F_ext = tstepper.eval( step_flag,
self.U_k,
self.t_n,
self.t_n1 )
#self.K = sparse.csr_matrix(K_full)
self.crpr_timer.record()
self.rtrace_mngr_timer.reset()
self.rtrace_mngr.record_iter( self.U_k )
self.rtrace_mngr_timer.record()
if adap.ihandler_needed():
adap.ihandler_invoke()
self.d_t *= adap.ihandler_get_scale()
self.t_n1 = self.t_n + self.d_t
step_flag = 'predictor'
self.k = 0
if LOGGING_ON:
log.info( "redo time step" )
continue
self.R_k = self.F_ext - self.F_int
if norm(self.R_k) < self.tolerance: # convergence satisfied
self.n_reset = 0
if LOGGING_ON:
log.info( "time step equilibrated in %d step(s)", self.k )
break # update_switch -> on
self.solv_timer.reset()
#self.d_U = solve(self.K,self.R_k)
#s_solve = linsolve.factorized(self.K)
#self.d_U = s_solve(self.R_k)
self.d_U = linsolve.spsolve(self.K,self.R_k) # DG_k * d_U = r
self.solv_timer.record()
self.U_k += self.d_U
self.k += 1
self.tot_k += 1
self.ttot_k += 1
step_flag = 'corrector'
else: # handling nonconverged step
if LOGGING_ON:
log.info("no convergence reached - refinement in time")
self.n_reset = self.n_reset + 1 # adaptive strategy halving d_t
if self.n_reset > self.RESETMAX: # max number of resets achieved
# Handle this situation with an exception with an
# associated dialog box and concise report of the
# iteration process
#
# @TODO raise the NoConvergence exception
if not self.sync_resp_tracing:
self.rtrace_mngr.stop_timer()
self.rtrace_mngr.timer_tick()
return
self.d_t *= adap.fhandler_get_scale()
self.t_n1 = self.t_n + self.d_t
if LOGGING_ON:
log.info("redo time step with dt = %s", )
continue
self.iter_timer.record()
#self.mem_counter.record()
if self.sync_resp_tracing:
self.rtrace_mngr.timer_tick()
if adap.ehandler_needed(): # explicit adaptations
if adap.ehandler_accept(): # accept equilibrium?
self.accept_time_step() # register the state and response
adap.ehandler_invoke()
else:
self.accept_time_step()
self.d_t *= adap.ehandler_get_scale()
self.t_n = self.t_n1
self.t_n1 = self.t_n + self.d_t
self.T.val = self.t_n1
# Report computation time
#
self.eval_timer.record()
self.eval_timer.report()
if not self.sync_resp_tracing:
self.rtrace_mngr.stop_timer()
self.rtrace_mngr.timer_tick()
return
b = array([12,15,20])
Afull[ix_(a),ix_(a)]=1.
Asp[a,b] = 1.
Bsp = Asp + Asp
#print Asp[ix_(a),ix_(b)]
Asp[2,:] = 3
Bsp = Asp + Asp
#Asp[ix_(a),5]=1.
print "after"
b = arange(1,1001)
Asp = Asp.astype('d')
xsp = linsolve.spsolve(Asp,b)
print xsp
print "finished"
Asp = sparse.dok_matrix((4,4))
Asp[2,:] = 5
Bsp = Asp + Asp
Asp[3,2] = 8
print 'col 2', Asp.getcol(2)
Bsp = Bsp + Asp
print 'Asp'
print Bsp[3,1]
def pde_interval(self, start, end):
""" compute the density evolution for the given interval """
# length of the time interval
U = end - start
# final density matrix for this interval
P_vt = zeros((self.W + 1, U))
# set initial value
if self.debug:
print "W", self.W
print "U", U
print P_vt
P_vt[self.V_reset_index, 0] = 1
for t in xrange(U - 1):
# V_rest as defined by lif
V_rest = self.lif.V_rest(start + t)
# A B and C diagonals of Lambda
A = zeros(self.W - 2)
B = zeros(self.W - 1)
C = zeros(self.W - 2)
# now we go and fill the matrix in
a, b, c, u, w = self.a, self.b, self.c, self.u, self.w
b_array = self.lif.g * (self.V_values[1:-1] / 2 - V_rest)
#here we scrapped the for loop, yes!
#but scrapped readability, no!
A[:] = -(2 * a * u + b_array[:] * w * u)
B[:] = ((4 * a * u) - (2 * c * w**2 * u) + (4 * w**2))
C[:] = -(2 * a * u - b_array[:] * w * u)
self.beta[1:-1] = (2*a*u + b_array[1:]*w*u) * P_vt[3:-1,t] + \
(-4*a*u + 2*c*w**2*u + 4*w**2) * P_vt[2:-2,t] + \
(2*a*u - b_array[:-1]*w*u) * P_vt[1:-3,t]
# now we set the diagonals of the tridiagonal matrix
self.Lambda.setdiag(A, 1)
self.Lambda.setdiag(B)
self.Lambda.setdiag(C, -1)
if self.debug:
print "A :", A
print "B :", B
print "C :", C
print "Lambda: ", self.Lambda.todense()
print "Lambda22: ", Lambda2.todense()
print "beta: ", self.beta
chi = linsolve.spsolve(self.Lambda, self.beta)
if self.debug:
print "chi:", chi
print "sumchi", chi.sum()
P_vt[1:-1, t + 1] = chi[:]
if self.debug: print "P_vt: ", P_vt
return P_vt
def solve(self, rhs):
return linsolve.spsolve( self.mtx, rhs )
QuickJacobian(x, Nb, Links, Tethers, D)
Dsp = sparse.csc_matrix(array(D))
_f = _FiberForce (Nb, x, Xss, Yss, Links, Tethers)
f = F - _f
e3 = 0. * x
z = x - e1 * x[Parts[7][0]] - e2 * x[Parts[7][0]+Nb]
for p in range(2,7):
for i in Parts[p]:
e3[i] = z[i+Nb]
e3[i+Nb] = -z[i]
f -= e3 * dot(f,e3) / dot(e3,e3)
y = linsolve.spsolve(Dsp,f)
y -= e3 * dot(y,e3) / dot(e3,e3)
damp = 1
x += damp * y
subMax = max(list(abs(f)))
print " submax:",subMax, " damp:",damp
f = _FiberForce (Nb, x, Xss, Yss, Links, Tethers)
r = b + dot(dt*A,f) - x
# clf(); plot(r); #&&raw_input("")
MaxRes = max(list(abs(r)))
