def test_shape_compatibility(self):
use_solver(useUmfpack=True)
A = csc_matrix([[1., 0], [0, 2]])
bs = [
[1, 6],
array([1, 6]),
[[1], [6]],
array([[1], [6]]),
csc_matrix([[1], [6]]),
csr_matrix([[1], [6]]),
dok_matrix([[1], [6]]),
bsr_matrix([[1], [6]]),
array([[1., 2., 3.], [6., 8., 10.]]),
csc_matrix([[1., 2., 3.], [6., 8., 10.]]),
csr_matrix([[1., 2., 3.], [6., 8., 10.]]),
dok_matrix([[1., 2., 3.], [6., 8., 10.]]),
bsr_matrix([[1., 2., 3.], [6., 8., 10.]]),
]
for b in bs:
x = np.linalg.solve(A.toarray(), toarray(b))
for spmattype in [csc_matrix, csr_matrix, dok_matrix, lil_matrix]:
x1 = spsolve(spmattype(A), b, use_umfpack=True)
x2 = spsolve(spmattype(A), b, use_umfpack=False)
# check solution
if x.ndim == 2 and x.shape[1] == 1:
# interprets also these as "vectors"
x = x.ravel()
assert_array_almost_equal(toarray(x1),
x,
err_msg=repr((b, spmattype, 1)))
assert_array_almost_equal(toarray(x2),
x,
err_msg=repr((b, spmattype, 2)))
# dense vs. sparse output ("vectors" are always dense)
if isspmatrix(b) and x.ndim > 1:
assert_(isspmatrix(x1), repr((b, spmattype, 1)))
assert_(isspmatrix(x2), repr((b, spmattype, 2)))
else:
assert_(isinstance(x1, np.ndarray), repr(
(b, spmattype, 1)))
assert_(isinstance(x2, np.ndarray), repr(
(b, spmattype, 2)))
# check output shape
if x.ndim == 1:
# "vector"
assert_equal(x1.shape, (A.shape[1], ))
assert_equal(x2.shape, (A.shape[1], ))
else:
# "matrix"
assert_equal(x1.shape, x.shape)
assert_equal(x2.shape, x.shape)
A = csc_matrix((3, 3))
b = csc_matrix((1, 3))
assert_raises(ValueError, spsolve, A, b)
def fit_model(phi, eps=0.):
assert phi.ndim == 2, 'data has to be two-dimensional'
assert phi.shape[1] > phi.shape[0], 'data samples have to be in columns'
d, nsamples = phi.shape
nij = d**2 - d # number of coupling terms
adata, arow, acol, b = fill_model_matrix(phi)
a = sparse.coo_matrix((adata, (arow, acol)), (nij, nij))
tic('matrix inversion')
if eps > 0:
a2 = np.dot(a.T,
a) + eps * nsamples * sparse.eye(nij, nij, format='coo')
b2 = np.dot(a.todense().T, np.atleast_2d(b).T)
# this sparse multiplication is buggy !!!!, I can't get the shape of b2 to be = (b.size,)
b3 = b2.copy().flatten().T
b3.shape = (b3.size, )
k_vec = dsolve.spsolve(a2.tocsr(), b3)
k_mat = np.zeros((d, d), complex)
k_mat.T[np.where(np.diag(np.ones(d)) - 1)] = k_vec.ravel()
else:
k_vec = dsolve.spsolve(a.tocsr(), b)
k_mat = np.zeros((d, d), complex)
k_mat.T[np.where(np.diag(np.ones(d)) - 1)] = k_vec
toc('matrix inversion')
return k_mat
def fit_model(phi, eps=0.):
assert phi.ndim == 2, 'data has to be two-dimensional'
assert phi.shape[1] > phi.shape[0], 'data samples have to be in columns'
d, nsamples = phi.shape
nij = d**2-d # number of coupling terms
adata, arow, acol, b = fill_model_matrix(phi)
a = sparse.coo_matrix((adata,(arow,acol)), (nij,nij))
tic('matrix inversion')
if eps > 0:
a2 = np.dot(a.T,a) + eps*nsamples*sparse.eye(nij,nij,format='coo')
b2 = np.dot(a.todense().T,np.atleast_2d(b).T)
# this sparse multiplication is buggy !!!!, I can't get the shape of b2 to be = (b.size,)
b3 = b2.copy().flatten().T
b3.shape = (b3.size,)
k_vec = dsolve.spsolve(a2.tocsr(),b3)
k_mat = np.zeros((d,d),complex)
k_mat.T[np.where(np.diag(np.ones(d))-1)] = k_vec.ravel()
else:
k_vec = dsolve.spsolve(a.tocsr(),b)
k_mat = np.zeros((d,d),complex)
k_mat.T[np.where(np.diag(np.ones(d))-1)] = k_vec
toc('matrix inversion')
return k_mat
def test_shape_compatibility(self):
use_solver(useUmfpack=True)
A = csc_matrix([[1., 0], [0, 2]])
bs = [
[1, 6],
array([1, 6]),
[[1], [6]],
array([[1], [6]]),
csc_matrix([[1], [6]]),
csr_matrix([[1], [6]]),
dok_matrix([[1], [6]]),
bsr_matrix([[1], [6]]),
array([[1., 2., 3.], [6., 8., 10.]]),
csc_matrix([[1., 2., 3.], [6., 8., 10.]]),
csr_matrix([[1., 2., 3.], [6., 8., 10.]]),
dok_matrix([[1., 2., 3.], [6., 8., 10.]]),
bsr_matrix([[1., 2., 3.], [6., 8., 10.]]),
]
for b in bs:
x = np.linalg.solve(A.toarray(), toarray(b))
for spmattype in [csc_matrix, csr_matrix, dok_matrix, lil_matrix]:
x1 = spsolve(spmattype(A), b, use_umfpack=True)
x2 = spsolve(spmattype(A), b, use_umfpack=False)
# check solution
if x.ndim == 2 and x.shape[1] == 1:
# interprets also these as "vectors"
x = x.ravel()
assert_array_almost_equal(toarray(x1), x, err_msg=repr((b, spmattype, 1)))
assert_array_almost_equal(toarray(x2), x, err_msg=repr((b, spmattype, 2)))
# dense vs. sparse output ("vectors" are always dense)
if isspmatrix(b) and x.ndim > 1:
assert_(isspmatrix(x1), repr((b, spmattype, 1)))
assert_(isspmatrix(x2), repr((b, spmattype, 2)))
else:
assert_(isinstance(x1, np.ndarray), repr((b, spmattype, 1)))
assert_(isinstance(x2, np.ndarray), repr((b, spmattype, 2)))
# check output shape
if x.ndim == 1:
# "vector"
assert_equal(x1.shape, (A.shape[1],))
assert_equal(x2.shape, (A.shape[1],))
else:
# "matrix"
assert_equal(x1.shape, x.shape)
assert_equal(x2.shape, x.shape)
A = csc_matrix((3, 3))
b = csc_matrix((1, 3))
assert_raises(ValueError, spsolve, A, b)
def test_dtype_cast(self):
A_real = scipy.sparse.csr_matrix([[1, 2, 0], [0, 0, 3], [4, 0, 5]])
A_complex = scipy.sparse.csr_matrix([[1, 2, 0], [0, 0, 3],
[4, 0, 5 + 1j]])
b_real = np.array([1, 1, 1])
b_complex = np.array([1, 1, 1]) + 1j * np.array([1, 1, 1])
x = spsolve(A_real, b_real)
assert_(np.issubdtype(x.dtype, np.floating))
x = spsolve(A_real, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_real)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
def n_springs(N, mu, f_vec):
"""
Compute the ratio $u_N/f_0$ for a chain
of $N$ springs. The range of frequencies
is given by $[f_{\min}, f_{\max}]$. $\mu$ is
the ratio of masses $\mu = m_2/m_1$.
"""
nfreq = len(f_vec)
uf_ratio = np.zeros(nfreq)
force = np.zeros(2 * N + 1)
force[0] = -1.0
for k, freq in enumerate(f_vec):
d_main = np.zeros(2 * N + 1)
d_main[1:-1:2] = -2. + mu * freq**2
d_main[2:-1:2] = -2. + freq**2
d_main[0] = -1.0 + freq**2
d_main[-1] = -1.0 + freq**2
d_low = np.ones(2 * N + 1)
data = [d_low, d_main, d_low]
diags = [-1, 0, 1]
A = sparse.spdiags(data, diags, 2 * N + 1, 2 * N + 1, format='csc')
x = dsolve.spsolve(A, force)
uf_ratio[k] = x[-1]
return uf_ratio
def Solve(self,fext,spcs):
if ( self.Kmat==None ):
print 'Kmat not set in FeSolver'
return
n=np.shape(self.Kmat)[0]
tr=0.0
for i in xrange(n):
tr += self.Kmat[i,i]
beta=tr/(1.0*n)
#nspc=len(spcs)
Kreac=self.Kmat.diagonal()
kappa = self.penfact*beta
for ispc in spcs:
ii = ispc.gid
iv = ispc.dval
for jj in xrange(n):
fext[jj] = fext[jj] - self.Kmat[jj,ii]*iv
for ispc in spcs:
ii = ispc.gid
self.Kmat[ii,ii] = kappa
fext[ii] = kappa*ispc.dval
self.Kmat=self.Kmat.tocsr()
d = dsolve.spsolve(self.Kmat, fext, use_umfpack=True)
for ii in xrange(n):
self.Kmat[ii,ii] = Kreac[ii]
freac = self.Kmat.dot(d)
return [d,freac]
def fesolve2(Kmat,fext,ispc,vspc=None): n=np.shape(Kmat)[0] tr=0.0 for i in xrange(n): tr += Kmat[i,i] beta=tr/(1.0*n) nspc=len(ispc) Kreac=Kmat[ispc,:].tocsr() if vspc==None: vspc=np.zeros((nspc,1)) else: # inhomogenious bc for i in xrange(nspc): ii = ispc[i] iv = vspc[i] for jj in xrange(Kmat.shape[0]): fext[jj] = fext[jj] - Kmat[jj,ii]*iv for i in xrange(nspc): ii = ispc[i] for jj in xrange(n): if ( not(Kmat[ii,jj]==0) ): Kmat[ii,jj] = 0.0 if ( not(Kmat[jj,ii]==0) ): Kmat[jj,ii] = 0.0 Kmat[ii,ii] = beta fext[ii] = beta*vspc[i] Kmat=Kmat.tocsr() d = dsolve.spsolve(Kmat, fext, use_umfpack=True) freac = Kreac.dot(d) return [d,freac]
def n_springs(N, mu, f_vec):
"""
Compute the ratio $u_N/f_0$ for a chain
of $N$ springs. The range of frequencies
is given by $[f_{\min}, f_{\max}]$. $\mu$ is
the ratio of masses $\mu = m_2/m_1$.
"""
nfreq = len(f_vec)
uf_ratio = np.zeros(nfreq)
force = np.zeros(2*N + 1)
force[0] = -1.0
for k, freq in enumerate(f_vec):
d_main = np.zeros(2*N + 1)
d_main[1:-1:2] = -2. + mu*freq**2
d_main[2:-1:2] = -2. + freq**2
d_main[0] = -1.0 + freq**2
d_main[-1] = -1.0 + freq**2
d_low = np.ones(2*N + 1)
data = [d_low, d_main, d_low]
diags = [-1,0,1]
A = sparse.spdiags(data, diags, 2*N+1, 2*N+1, format='csc')
x = dsolve.spsolve(A, force)
uf_ratio[k] = x[-1]
return uf_ratio
def step_elliptical_1d(dx, W, alpha, beta, gamma, left_boundary_condition,
left_boundary_condition_value, right_boundary_condition,
right_boundary_condition_value):
#
# Solves 1D elliptical equation on staggered grid
# (W(x) u_x)_x - alpha(x) u + gamma(x)*u_x = beta(x)
#
def boundary_modifier(x, val):
return {'Dirichlet': [val, 0, val], 'vonNeuman': [-val, val, -val]}[x]
N_intervals = np.size(alpha) - 1
val = np.mean(np.abs(2 * W + dx**2.0 * alpha - gamma * dx))
left_modifier = boundary_modifier(left_boundary_condition, val)
right_modifier = boundary_modifier(right_boundary_condition, val)
rhs = dx * dx * beta
rhs[0] = left_modifier[2] * left_boundary_condition_value
rhs[np.size(rhs) - 1] = right_modifier[2] * right_boundary_condition_value
A = csc_matrix(
spdiags([
np.hstack((W[0:N_intervals - 1], right_modifier[1], 0)),
np.hstack(
(left_modifier[0], -(W[0:N_intervals - 1] + W[1:N_intervals] +
alpha[1:N_intervals] * dx * dx) -
(gamma[1:N_intervals] + gamma[0:N_intervals - 1]) / 2.0 * dx,
right_modifier[0])),
np.hstack(
(0, left_modifier[1], W[1:N_intervals] +
(gamma[1:N_intervals] + gamma[0:N_intervals - 1]) / 2.0 * dx))
], [-1, 0, 1], N_intervals + 1, N_intervals + 1))
u = dsolve.spsolve(A, rhs, use_umfpack=True)
return u
def step_diffusion_1d(dt, dx, phi, sourceTerm, D, left_boundary_condition,
left_boundary_condition_value, right_boundary_condition,
right_boundary_condition_value):
#
# Solves 1D diffusion on staggered grid; give the midpotins only, not the artificial points outside the boundary, they are specified by the given boundary condition.
# Input values are dt, dx, phi (solution in the previous time-step) on the nodes, source term on the nodes, diffusion coefficient vector on midpoints (size N+1)
# Boundary conditions can be vonNeuman or Dirichlet
#
def boundary_modifier(x, dx):
return {'Dirichlet': [1, 0, 1], 'vonNeuman': [1, -1, dx]}[x]
N_intervals = np.size(phi) - 1
rhs = -dx * dx * (phi / dt + sourceTerm)
left_modifier = boundary_modifier(left_boundary_condition, dt)
right_modifier = boundary_modifier(right_boundary_condition, dt)
if left_boundary_condition == 'vonNeuman':
rhs[0] = -left_modifier[2] * left_boundary_condition_value
elif left_boundary_condition == 'Dirichlet':
rhs[0] = left_modifier[2] * left_boundary_condition_value
rhs[-1] = right_modifier[2] * right_boundary_condition_value
A = csc_matrix(
spdiags([
np.hstack((D[0:N_intervals - 1], right_modifier[1], 0)),
np.hstack(
(left_modifier[0],
-(D[0:N_intervals - 1] + D[1:N_intervals] + dx * dx / dt),
right_modifier[0])),
np.hstack((0, left_modifier[1], D[1:N_intervals]))
], [-1, 0, 1], N_intervals + 1, N_intervals + 1))
phi = dsolve.spsolve(A, rhs, use_umfpack=True)
return phi
def Solve(self, fext, spcs):
if (self.Kmat == None):
print 'Kmat not set in FeSolver'
return
n = np.shape(self.Kmat)[0]
tr = 0.0
for i in xrange(n):
tr += self.Kmat[i, i]
beta = tr / (1.0 * n)
#nspc=len(spcs)
Kreac = self.Kmat.diagonal()
kappa = self.penfact * beta
for ispc in spcs:
ii = ispc.gid
iv = ispc.dval
for jj in xrange(n):
fext[jj] = fext[jj] - self.Kmat[jj, ii] * iv
for ispc in spcs:
ii = ispc.gid
self.Kmat[ii, ii] = kappa
fext[ii] = kappa * ispc.dval
self.Kmat = self.Kmat.tocsr()
d = dsolve.spsolve(self.Kmat, fext, use_umfpack=True)
for ii in xrange(n):
self.Kmat[ii, ii] = Kreac[ii]
freac = self.Kmat.dot(d)
return [d, freac]
def fesolve2(Kmat, fext, ispc, vspc=None):
n = np.shape(Kmat)[0]
tr = 0.0
for i in xrange(n):
tr += Kmat[i, i]
beta = tr / (1.0 * n)
nspc = len(ispc)
Kreac = Kmat[ispc, :].tocsr()
if vspc == None:
vspc = np.zeros((nspc, 1))
else: # inhomogenious bc
for i in xrange(nspc):
ii = ispc[i]
iv = vspc[i]
for jj in xrange(Kmat.shape[0]):
fext[jj] = fext[jj] - Kmat[jj, ii] * iv
for i in xrange(nspc):
ii = ispc[i]
for jj in xrange(n):
if (not (Kmat[ii, jj] == 0)):
Kmat[ii, jj] = 0.0
if (not (Kmat[jj, ii] == 0)):
Kmat[jj, ii] = 0.0
Kmat[ii, ii] = beta
fext[ii] = beta * vspc[i]
Kmat = Kmat.tocsr()
d = dsolve.spsolve(Kmat, fext, use_umfpack=True)
freac = Kreac.dot(d)
return [d, freac]
def test_singular(self):
A = csc_matrix((5,5), dtype='d')
b = array([1, 2, 3, 4, 5],dtype='d')
with suppress_warnings() as sup:
sup.filter(MatrixRankWarning, "Matrix is exactly singular")
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
def test_singular(self):
A = csc_matrix((5, 5), dtype='d')
b = array([1, 2, 3, 4, 5], dtype='d')
with suppress_warnings() as sup:
sup.filter(MatrixRankWarning, "Matrix is exactly singular")
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
def solve(self):
self.populate_matrix_6th_order() if self.uniform else self.populate_matrix()
self.populate_vector()
self.apply_boundary_conditions()
self.mtx = sparse.csr_matrix(self.mtx)
self.mtx = self.mtx.astype(np.float64)
self.U = dsolve.spsolve(self.mtx, np.array(self.vec), use_umfpack=True)
def test_singular(self):
with warnings.catch_warnings():
warnings.simplefilter("ignore", category=MatrixRankWarning)
A = csc_matrix((5,5), dtype='d')
b = array([1, 2, 3, 4, 5],dtype='d')
x = spsolve(A, b, use_umfpack=False)
assert_(not np.isfinite(x).any())
def test_singular(self):
with warnings.catch_warnings():
warnings.simplefilter("ignore", category=MatrixRankWarning)
A = csc_matrix((5,5), dtype='d')
b = array([1, 2, 3, 4, 5],dtype='d')
x = spsolve(A, b, use_umfpack=False)
assert_(not np.isfinite(x).any())
def test_sparsity_preservation(self):
ident = csc_matrix([[1, 0, 0], [0, 1, 0], [0, 0, 1]])
b = csc_matrix([[0, 1], [1, 0], [0, 0]])
x = spsolve(ident, b)
assert_equal(ident.nnz, 3)
assert_equal(b.nnz, 2)
assert_equal(x.nnz, 2)
assert_allclose(x.A, b.A, atol=1e-12, rtol=1e-12)
def test_dtype_cast(self):
A_real = scipy.sparse.csr_matrix([[1, 2, 0],
[0, 0, 3],
[4, 0, 5]])
A_complex = scipy.sparse.csr_matrix([[1, 2, 0],
[0, 0, 3],
[4, 0, 5 + 1j]])
b_real = np.array([1,1,1])
b_complex = np.array([1,1,1]) + 1j*np.array([1,1,1])
x = spsolve(A_real, b_real)
assert_(np.issubdtype(x.dtype, np.floating))
x = spsolve(A_real, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_real)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
def test_bmatrix_smoketest(self):
Adense = array([[0., 1., 1.], [1., 0., 1.], [0., 0., 1.]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3, 4)
Bdense = As.dot(x)
Bs = csc_matrix(Bdense)
x2 = spsolve(As, Bs)
assert_array_almost_equal(x, x2.todense())
def test_bvector_smoketest(self):
Adense = array([[0., 1., 1.], [1., 0., 1.], [0., 0., 1.]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3)
b = As * x
x2 = spsolve(As, b)
assert_array_almost_equal(x, x2)
def start_solving_newton(self):
""" Starts solving the problem.
"""
self.mesh.output_vtk_mesh(self.model_name + "0",
[self.current_pressure,
self.mesh.get_cell_domain_all()],
["pressure", "domain"])
self.time_step_output(0., 0)
m_multipliers = np.ones(self.mesh.get_number_of_cells(), dtype=np.dtype('d'))
for time_step in range(1,self.number_of_time_steps+1):
current_time = time_step*self.delta_t
print(time_step)
print("\n")
for i in range(100):
rhs_current = np.zeros(self.mfd.get_number_of_dof(), dtype=np.dtype('d'))
rhs_current += self.rhs_mfd
for cell_index in range(self.mesh.get_number_of_cells()):
density = -self.ref_pressure
density += self.current_pressure[cell_index]
density *= self.compressibility
density += 1.
density *= self.ref_density
# We multiply by the inverse of \frac{\rho}{\mu}
m_multipliers[cell_index] = self.viscosity/density
c_entry = self.compressibility
c_entry *= self.porosities[cell_index]
c_entry /= self.delta_t
c_entry *= self.mesh.get_cell_volume(cell_index)
rhs_current[self.mfd.flux_dof+
cell_index] += c_entry*self.current_pressure[cell_index]
self.lhs_coo.data[self.c_start+cell_index] = c_entry
for [index, cell_index] in enumerate(self.rate_wells):
rhs_current[self.mfd.flux_dof+cell_index] += \
self.rate_wells_rate[index]
self.mfd.update_m(self.lhs_coo.data[:self.m_x_coo_length], m_multipliers)
solution = dsolve.spsolve(self.lhs_coo.tocsr(), rhs_current)
print(np.linalg.norm(self.current_pressure-solution[self.mfd.flux_dof:]))
self.current_pressure = solution[self.mfd.flux_dof:]
self.current_velocity = solution[:self.mfd.flux_dof]
if time_step%self.output_frequency == 0:
self.mesh.output_vtk_mesh(self.model_name+str(time_step),
[self.current_pressure,
self.mesh.get_cell_domain_all()],
["pressure", "domain"])
self.time_step_output(current_time, time_step)
def test_bvector_smoketest(self):
Adense = matrix([[0.0, 1.0, 1.0], [1.0, 0.0, 1.0], [0.0, 0.0, 1.0]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3)
b = As * x
x2 = spsolve(As, b)
assert_array_almost_equal(x, x2)
def test_bmatrix_smoketest(self):
Adense = matrix([[0.0, 1.0, 1.0], [1.0, 0.0, 1.0], [0.0, 0.0, 1.0]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3, 4)
Bdense = As.dot(x)
Bs = csc_matrix(Bdense)
x2 = spsolve(As, Bs)
assert_array_almost_equal(x, x2.todense())
def start_solving_newton(self):
""" Starts solving the problem.
"""
self.mesh.output_vtk_mesh(self.model_name + "0",
[self.current_pressure,
self.mesh.get_cell_domain_all()],
["pressure", "domain"])
self.time_step_output(0., 0)
m_multipliers = np.ones(self.mesh.get_number_of_cells(), dtype=np.dtype('d'))
for time_step in range(1,self.number_of_time_steps+1):
current_time = time_step*self.delta_t
print(time_step)
print("\n")
for i in range(100):
rhs_current = np.zeros(self.mfd.get_number_of_dof(), dtype=np.dtype('d'))
rhs_current += self.rhs_mfd
for cell_index in range(self.mesh.get_number_of_cells()):
density = -self.ref_pressure
density += self.current_pressure[cell_index]
density *= self.compressibility
density += 1.
density *= self.ref_density
# We multiply by the inverse of \frac{\rho}{\mu}
m_multipliers[cell_index] = self.viscosity/density
c_entry = self.compressibility
c_entry *= self.porosities[cell_index]
c_entry /= self.delta_t
c_entry *= self.mesh.get_cell_volume(cell_index)
rhs_current[self.mfd.flux_dof+
cell_index] += c_entry*self.current_pressure[cell_index]
self.lhs_coo.data[self.c_start+cell_index] = c_entry
for [index, cell_index] in enumerate(self.rate_wells):
rhs_current[self.mfd.flux_dof+cell_index] += \
self.rate_wells_rate[index]
self.mfd.update_m(self.lhs_coo.data[:self.m_x_coo_length], m_multipliers)
solution = dsolve.spsolve(self.lhs_coo.tocsr(), rhs_current)
print(np.linalg.norm(self.current_pressure-solution[self.mfd.flux_dof:]))
self.current_pressure = solution[self.mfd.flux_dof:]
self.current_velocity = solution[:self.mfd.flux_dof]
if time_step%self.output_frequency == 0:
self.mesh.output_vtk_mesh(self.model_name+str(time_step),
[self.current_pressure,
self.mesh.get_cell_domain_all()],
["pressure", "domain"])
self.time_step_output(current_time, time_step)
def FDM_implicit(self,
bc0=[-1.5, 2., -.5, 0.],
bcn=[1.5, -2., .5, 0.],
lowerbound=0):
"""
Calculate one step of the implicit Finite Elements Method for Fick's
second law equation.
Parameters
----------
bc0 : array_like
Parameters for the boundary condition at the 0-th node
bcn : array_like
Parameters for the boundary condition at the n-th node
At the 0-th node, the correspondent linear equation is given by
bc0[0]*c[0] + bc0[1]*c[1] + bc0[1]*c[2] = bc0[3].
At the n-th node, the correspondent linear equation is given by
bcn[0]*c[-1] + bcn[1]*c[-2] + bcn[2]*c[-3] = bcn[3].
Dirichlet boundary condition is given by bc0/bcn = (1.,0.,0.,c_i).
Neumann boundary condition (flux = 0) can be defined either by
bc0 (bcn) = [1.5,-2.,.5,0.] or bc0 (bcn) = [1.,-1.,0.,0.]
"""
self.get_r()
self.get_g()
dia1_, dia1 = np.zeros(self.n), np.zeros(self.n)
dia2_, dia2 = np.zeros(self.n), np.zeros(self.n)
dia0 = 1. + 2. * self.r
dia1_[:-1], dia1[1:] = -(self.r[1:] - self.g[1:]), -(self.r[:-1] +
self.g[:-1])
self._b[:] = self.c
# First row of the matrix. Determines the boundary condition at i=0
dia0[0], dia1[1], dia2[2] = bc0[0], bc0[1], bc0[2]
# Determines the boundary condition at i=0
self._b[0] = bc0[3]
# Last row of the matrix. Determines the boundary condition at i=n
dia0[-1], dia1_[-2], dia2_[-3] = bcn[0], bcn[1], bcn[2]
# Determines the boundary condition at i=n
self._b[-1] = bcn[3]
mtx = spdiags([dia2_, dia1_, dia0, dia1, dia2], [-2, -1, 0, 1, 2],
self.n, self.n)
A = csc_matrix(mtx, dtype=np.float64)
# Solve the linear system A*c = b
self._c = dsolve.spsolve(A, self._b, use_umfpack=True)
if self._c[0] < lowerbound or self._c[-1] < lowerbound:
return True
self.c[:] = self._c
def tick_fem_sparse(self,dt):
"""
tick Finite Element Model simulation by dt hours using sparse stiffness matrix
"""
# initialise stiffness matrix
self.stiffness=sparse.lil_matrix((self.numnodes*self.NUMDOF,self.numnodes*self.NUMDOF))
#self.stiffness=numpy.zeros((self.numnodes*self.NUMDOF,self.numnodes*self.NUMDOF))
# for each wall, add a component to the stiffness matrix
for wall in self.walls:
L=wall.get_length()
Ra = self.FEM_E*self.FEM_S/L/dt
Rf = self.FEM_E*self.FEM_I/(L**3)/dt
M =numpy.array(((Ra , 0 , 0 , -Ra , 0 , 0 ),
(0 , Rf*12 , -Rf*6*L , 0 , -Rf*12 , -Rf*6*L ),
(0 , -Rf*6*L , Rf*4*L**2 , 0 , Rf*6*L , Rf*2*L**2 ),
(-Ra , 0 , 0 , Ra , 0 , 0 ),
(0 , -Rf*12 , Rf*6*L , 0 , Rf*12 , Rf*6*L ),
(0 , -Rf*6*L , Rf*2*L**2 , 0 , Rf*6*L , Rf*4*L**2 )))
# rotate from local coord frame to global
theta=wall.get_angle()
c=wall.get_cosine() #math.cos(theta)
s=wall.get_sine() #math.sin(theta)
R=numpy.array(((c,-s,0),
(s,c,0),
(0,0,1)))
R=numpy.hstack((R,R))
R=numpy.vstack((R,R))
MR=R*M*R.transpose()
# add component to stiffness matrix
self.stiffness[wall.node0.id*3:wall.node0.id*3+3,wall.node0.id*3:wall.node0.id*3+3]+=sparse.lil_matrix(MR[0:3,0:3])
self.stiffness[wall.node1.id*3:wall.node1.id*3+3,wall.node1.id*3:wall.node1.id*3+3]+=sparse.lil_matrix(MR[3:6,3:6])
self.stiffness[wall.node0.id*3:wall.node0.id*3+3,wall.node1.id*3:wall.node1.id*3+3]+=sparse.lil_matrix(MR[0:3,3:6])
self.stiffness[wall.node1.id*3:wall.node1.id*3+3,wall.node0.id*3:wall.node0.id*3+3]+=sparse.lil_matrix(MR[3:6,0:3])
#print_mat(self.stiffness)
# apply turgor force
self.nodeforcearray=numpy.zeros(self.nodeforcearray.shape)
for cell in self.cells.values():
cell.apply_turgor(0.01)
#self.cells.values()[0].apply_turgor(0.001)
# solve for displacement (find d in S.d=f)
# fixing first node
f=self.nodeforcearray[3:]
s=self.stiffness[3:,3:]
#d=linalg.solve(s,f)
d=linsolve.spsolve(s.tocsr(),f)
self.nodedisparray[3:]+=d.reshape(d.shape[0],1)
def ResoLpl(f22D,N,M):
global dx
global dy
global LAP2
f2 = f22D.reshape(N*M)
T = spsolve(LAP2,f2) # Solving the linear system
u2D=T.reshape(N,M)
return u2D
def ResoLpl(f22D, N, M):
global dx
global dy
global LAP2
f2 = f22D.reshape(N * M)
T = spsolve(LAP2, f2) # Solving the linear system
u2D = T.reshape(N, M)
return u2D
def solveHJB(mu1, mu2, sigma, lambda1, lambda2, Kb, Ks, rho, T):
Ny = 1000
Nt = 200
beta = 1e7
tol = 1e-8
psell = []
pbuy = []
h = 1.0/Ny
dt = T*1.0/Nt
y = np.array([h*i for i in range(Ny+1)])
v = np.array([np.log(1-Ks) for i in range(Ny+1)])
vnew = [1 for i in range(Ny+1)]
c2 = 0.5*np.array([((mu1-mu2)*x*(1-x)/sigma)**2 for x in y])/h/h
c1 = (-(lambda1+lambda2)*y+lambda2)/h
c0 = 0
f0= (mu1-mu2)*y+(mu2-rho-sigma**2/2)
left = -c2+c1*(c1<0)
middle = 1/dt+2*c2+np.abs(c1)-c0;
right = -c2-c1*(c1>0)
for t in range(int(T/dt)):
counter = 0
vn = v
while True:
counter = counter+1
Indi1 = beta*(v-(np.log(1+Kb))>0);
Indi2 = beta*((np.log(1-Ks))-v>0);
b = vn/dt+(np.log(1+Kb))*Indi1+(np.log(1-Ks))*Indi2+f0;
A = scipy.sparse.spdiags(np.array([right, middle+Indi1+Indi2, left]),[-1,0,1],Ny+1,Ny+1).T
b[0] = A[0,0]*np.log(1-Ks)
A[0,1] = 0
b[Ny] = A[Ny,Ny]*np.log(1+Kb)
A[Ny,Ny-1]=0
vnew = dsolve.spsolve(A,b,use_umfpack=False)
if (np.linalg.norm(vnew-v)*1.0/np.linalg.norm(v))<tol:
break
v = vnew
uu = vnew
temp = np.where(uu-(np.log(1+Kb))>=0)[0]
pbuy.append(y[temp[0]])
temp = np.where(uu-(np.log(1-Ks))<=0)[0]
psell.append(y[temp[len(temp)-1]])
return [pbuy[Nt-1], psell[Nt-1]]
def solve_linear_system(self, A=None, use_Wendland_compsupp=True, regularisation=None, save_Gram_rows=[False,None],
verbose=False):
"""
Solves the linear system defined by generalised interpolation problem
:param A: Interpolation matrix
:param use_Wendland_compsupp: When A is not given and the kernel is Wendland kernel, use the
compact support to speed up population of interpolation matrix.
:param save_Gram_rows: Option to save Gram matrix row-by-row - 2nd list element is for path
(currently only for gram_Wendland())
:return: solution vector stored in self.coefficients
"""
#TODO: Implement save_Gram_rows for other gram functions
if regularisation!=None:
self.regularisation=regularisation
# Check the Data list is not empty
data_empty = True
for data_object in self.data_points:
if data_object.numpoints > 0: data_empty = False
if data_empty == True:
print("ERROR: Cannot solve linear system - no data points")
exit(1)
self._check_for_empty_Data()
if A==None:
if verbose: print('making Gram matrix')
if use_Wendland_compsupp==False or not isinstance(self.K, Wendland):
if verbose: print('using gram')
self.gram = gram(self)
else:
if verbose: print('using gram_Wendland')
self.gram = gram_Wendland(self, save_rows=save_Gram_rows)
if verbose: print('finished making Gram matrix')
else:
self._check_gram(A)
self.gram = A
#if self.regularisation != 0:
# print('Adding regularisation: ', self.regularisation)
# self.gram = self.gram + (self.regularisation * sparse.identity(self.gram.shape[0]))
if verbose: print('solving linear system')
self.beta = np.array([])
for data_object in self.data_points:
#self.dim = data_object.points.shape[0]
self.beta = np.hstack((self.beta, data_object.targets))
if sparse.issparse(self.gram):
if not isinstance(self.gram, sparse.csr.csr_matrix):
self.gram = sparse.csr_matrix(self.gram)
self.coefficients = spsolve(self.gram + (self.regularisation * sparse.identity(self.gram.shape[0])), self.beta)
else:
self.coefficients = np.linalg.solve(self.gram + (self.regularisation * sparse.identity(self.gram.shape[0])), self.beta)
if verbose: print('finished linear system')
def test_sparsity_preservation(self):
ident = csc_matrix([
[1, 0, 0],
[0, 1, 0],
[0, 0, 1]])
b = csc_matrix([
[0, 1],
[1, 0],
[0, 0]])
x = spsolve(ident, b)
assert_equal(ident.nnz, 3)
assert_equal(b.nnz, 2)
assert_equal(x.nnz, 2)
assert_allclose(x.A, b.A, atol=1e-12, rtol=1e-12)
def solvePoissonProblem_sparse(mesh, densityValues):
"""
Solve a Poisson problem on the mesh, using sparse matrix operations.
This will be nearly identical to the dense method.
The results should be stored on the vertices in a variable named 'solutionVal'.
densityValues is a dictionary mapping {vertex ==> value} that specifies any
densities. The density is implicitly zero at every vertex not in this dictionary.
Note: Be sure to look at the notes on the github wiki about sparse matrix
computation in Python.
When you run this program with 'python Assignment3.py part2 path/to/your/mesh.obj',
you will get to click on vertices to specify density conditions. See the
assignment document for more details.
"""
index_map = enumerateVertices(mesh)
L = buildLaplaceMatrix_sparse(mesh, index_map)
M = buildMassMatrix_dense(mesh, index_map) #M <= 2D
rho = np.zeros((len(mesh.verts)), float)
for key in densityValues:
#index_val = index_map[key]
print 'key dual area = ', key.dualArea
rho[index_map[key]] = densityValues[key] #*key.dualArea
# convert to sparse matrix (CSR method)
#Lsparse = csr_matrix(L)
#iL = np.linalg.inv(L)
#sol_vec = np.dot(iL,rho)
#sol_vec = np.linalg.solve(L, rho)
#sol_vec = linsolve.spsolve(L, rho)
#sol_vec = linsolve.spsolve(L, np.dot(M,rho) )
#sol_vec = dsolve.spsolve(L, rho, use_umfpack=False)
sol_vec = dsolve.spsolve(L, np.dot(M, rho), use_umfpack=True)
for vert in mesh.verts:
key = index_map[vert]
#print 'TLM sol_vec = ',sol_vec[key]
vert.solutionVal = sol_vec[key]
if rho[key]:
vert.densityVal = rho[key]
else:
vert.densityVal = 0.
return
def computeCoExactComponent(self, omega):
print 'system 2, Beta'
#solve system 2 for delta Beta
# page 117-118-119
# scipy.linalg.lu
print 'build LHS...'
t0 = time.time()
LHS = self.d1.dot(self.ihodge1)
#ss = np.shape(LHS)[0]
LHS = csc_matrix(LHS)
LHS = LHS.dot(self.d1T)
#LHS = LHS + 1.e-8 * csc_matrix(np.identity(ss,float))
#
tSolve = time.time() - t0
print("...sparse Beta LHS build completed.")
print("Beta LHS build took {:.5f} seconds.".format(tSolve))
print 'build RHS...'
t0 = time.time()
#RHS = np.matmul(d1,omega)
RHS = self.d1.dot(omega)
tSolve = time.time() - t0
print("...sparse Beta RHS completed.")
print("Beta RHS build took {:.5f} seconds.".format(tSolve))
print 'solve'
Beta = dsolve.spsolve(LHS, RHS, use_umfpack=True)
#LU decomposition:
#DLU = scipy.sparse.linalg.splu(LHS)
#Beta = DLU.solve(RHS)
# print 'solve complete, transform'
# Beta = np.dot(ihodge2,Beta)
# print 'transform complete, Beta complete'
#
# store exact, coexact, harmonic components on the mesh edges.
print 'decomposition field to mesh'
#now pull back to a 1 form using the codifferential *d*
# *d* Beta => *d0*
#Beta = np.dot(hodge0,np.dot(d0,
# np.dot(hodge2,Beta)))
# the easy way:
Beta = self.d1T.dot(Beta)
print 'solve complete, transform Beta'
Beta = np.dot(self.ihodge1, Beta)
print 'transform complete, Beta complete'
return Beta
def test_singular_gh_3312(self):
# "Bad" test case that leads SuperLU to call LAPACK with invalid
# arguments. Check that it fails moderately gracefully.
ij = np.array([(17, 0), (17, 6), (17, 12), (10, 13)], dtype=np.int32)
v = np.array([0.284213, 0.94933781, 0.15767017, 0.38797296])
A = csc_matrix((v, ij.T), shape=(20, 20))
b = np.arange(20)
try:
# should either raise a runtimeerror or return value
# appropriate for singular input
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
except RuntimeError:
pass
def test_singular_gh_3312(self):
# "Bad" test case that leads SuperLU to call LAPACK with invalid
# arguments. Check that it fails moderately gracefully.
ij = np.array([(17, 0), (17, 6), (17, 12), (10, 13)], dtype=np.int32)
v = np.array([0.284213, 0.94933781, 0.15767017, 0.38797296])
A = csc_matrix((v, ij.T), shape=(20, 20))
b = np.arange(20)
try:
# should either raise a runtimeerror or return value
# appropriate for singular input
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
except RuntimeError:
pass
def test_example_comparison(self):
row = array([0, 0, 1, 2, 2, 2])
col = array([0, 2, 2, 0, 1, 2])
data = array([1, 2, 3, -4, 5, 6])
sM = csr_matrix((data, (row, col)), shape=(3, 3), dtype=float)
M = sM.todense()
row = array([0, 0, 1, 1, 0, 0])
col = array([0, 2, 1, 1, 0, 0])
data = array([1, 1, 1, 1, 1, 1])
sN = csr_matrix((data, (row, col)), shape=(3, 3), dtype=float)
N = sN.todense()
sX = spsolve(sM, sN)
X = scipy.linalg.solve(M, N)
assert_array_almost_equal(X, sX.todense())
def test_twodiags(self):
A = spdiags([[1, 2, 3, 4, 5], [6, 5, 8, 9, 10]], [0, 1], 5, 5)
b = array([1, 2, 3, 4, 5])
# condition number of A
cond_A = norm(A.todense(), 2) * norm(inv(A.todense()), 2)
for t in ['f', 'd', 'F', 'D']:
eps = finfo(t).eps # floating point epsilon
b = b.astype(t)
for format in ['csc', 'csr']:
Asp = A.astype(t).asformat(format)
x = spsolve(Asp, b)
assert_(norm(b - Asp * x) < 10 * cond_A * eps)
def test_example_comparison(self):
row = array([0,0,1,2,2,2])
col = array([0,2,2,0,1,2])
data = array([1,2,3,-4,5,6])
sM = csr_matrix((data,(row,col)), shape=(3,3), dtype=float)
M = sM.todense()
row = array([0,0,1,1,0,0])
col = array([0,2,1,1,0,0])
data = array([1,1,1,1,1,1])
sN = csr_matrix((data, (row,col)), shape=(3,3), dtype=float)
N = sN.todense()
sX = spsolve(sM, sN)
X = scipy.linalg.solve(M, N)
assert_array_almost_equal(X, sX.todense())
def test_twodiags(self):
A = spdiags([[1, 2, 3, 4, 5], [6, 5, 8, 9, 10]], [0, 1], 5, 5)
b = array([1, 2, 3, 4, 5])
# condition number of A
cond_A = norm(A.todense(),2) * norm(inv(A.todense()),2)
for t in ['f','d','F','D']:
eps = finfo(t).eps # floating point epsilon
b = b.astype(t)
for format in ['csc','csr']:
Asp = A.astype(t).asformat(format)
x = spsolve(Asp,b)
assert_(norm(b - Asp*x) < 10 * cond_A * eps)
def test_example_comparison(self):
with warnings.catch_warnings():
warnings.simplefilter("ignore", category=SparseEfficiencyWarning)
row = array([0,0,1,2,2,2])
col = array([0,2,2,0,1,2])
data = array([1,2,3,-4,5,6])
sM = csr_matrix((data,(row,col)), shape=(3,3), dtype=float)
M = sM.todense()
row = array([0,0,1,1,0,0])
col = array([0,2,1,1,0,0])
data = array([1,1,1,1,1,1])
sN = csr_matrix((data, (row,col)), shape=(3,3), dtype=float)
N = sN.todense()
sX = spsolve(sM, sN)
X = scipy.linalg.solve(M, N)
assert_array_almost_equal(X, sX.todense())
def SchurPCD2(Mass,L,F, backend):
Mass = Mass.sparray()
F = F.sparray()
L = L.sparray()
X = np.empty_like(Mass.todense())
print X.shape
Mass = Mass+ 1e-4*sp.identity(Mass.shape[0])
Mass = Mass.toarray()
print np.array(Mass[:,0]).T
for i in range(X.shape[1]):
print Mass[i,:].T
X[i,:] = spsolve(F,Mass[:,i]) # print Schur.todense()
Schur = L*X
print Schur.diagonal()
if backend == "PETSc":
return PETSc.Mat().createAIJ(size=Schur.transpose().shape,csr=(Schur.transpose().indptr, Schur.transpose().indices, Schur.transpose().data))
else:
return Schur.transpose()
def test_example_comparison(self):
with warnings.catch_warnings():
warnings.simplefilter("ignore", category=SparseEfficiencyWarning)
row = array([0, 0, 1, 2, 2, 2])
col = array([0, 2, 2, 0, 1, 2])
data = array([1, 2, 3, -4, 5, 6])
sM = csr_matrix((data, (row, col)), shape=(3, 3), dtype=float)
M = sM.todense()
row = array([0, 0, 1, 1, 0, 0])
col = array([0, 2, 1, 1, 0, 0])
data = array([1, 1, 1, 1, 1, 1])
sN = csr_matrix((data, (row, col)), shape=(3, 3), dtype=float)
N = sN.todense()
sX = spsolve(sM, sN)
X = scipy.linalg.solve(M, N)
assert_array_almost_equal(X, sX.todense())
def solve(self):
'''
Solve the PDE.
'''
maxiter = 50
trace = True
for iter in xrange(0, maxiter):
self.state.clearFunJac()
self.calcFunJac()
self.state.assembleJac()
flagConv, err = self.checkConv()
if trace:
print iter, err
if flagConv:
break
dx = np.negative(dsolve.spsolve(self.state.J, self.state.b))
self.state.dx = self.dampStep(dx)
self.state.x = np.add(self.state.x, self.state.dx)
def solve(self):
'''
Solve the PDE.
'''
maxiter=50
trace = True
for iter in xrange(0,maxiter):
self.state.clearFunJac()
self.calcFunJac()
self.state.assembleJac()
flagConv, err = self.checkConv()
if trace:
print iter, err
if flagConv:
break
dx = np.negative(dsolve.spsolve(self.state.J, self.state.b))
self.state.dx = self.dampStep(dx)
self.state.x = np.add(self.state.x, self.state.dx)
def update_pressure(self):
""" Updates the pressure equation explicitly
"""
m_multipliers = np.ones(self.mesh.get_number_of_cells())
rhs_current = np.zeros(self.mfd.get_number_of_dof())
rhs_current += self.rhs_mfd
for cell_index in range(self.mesh.get_number_of_cells()):
density = -self.ref_pressure
density += self.current_pressure[cell_index]
density *= self.compressibility
density += 1.
density *= self.ref_density
# We multiply by the inverse of \frac{\rho}{\mu}
m_multipliers[cell_index] = self.viscosity/density
c_entry = self.compressibility
c_entry *= self.porosities[cell_index]
c_entry /= self.delta_t
c_entry *= self.mesh.get_cell_volume(cell_index)
rhs_current[self.mesh.get_number_of_faces()+
cell_index] += c_entry*self.current_pressure[cell_index]
self.lhs_coo.data[self.c_start+cell_index] = c_entry
for [index, cell_index] in enumerate(self.rate_wells):
rhs_current[self.mesh.get_number_of_faces()+cell_index] += \
self.rate_wells_rate[index]
self.mfd.update_m(self.lhs_coo.data[:self.m_x_coo_length], m_multipliers)
solution = dsolve.spsolve(self.lhs_coo.tocsr(), rhs_current)
self.prev_pressure = self.current_pressure
self.current_pressure = solution[self.mesh.get_number_of_faces():]
self.current_velocity = solution[:self.mesh.get_number_of_faces()]
def update_pressure(self):
""" Updates the pressure equation explicitly
"""
m_multipliers = np.ones(self.mesh.get_number_of_cells())
rhs_current = np.zeros(self.mfd.get_number_of_dof())
rhs_current += self.rhs_mfd
for cell_index in range(self.mesh.get_number_of_cells()):
density = -self.ref_pressure
density += self.current_pressure[cell_index]
density *= self.compressibility
density += 1.
density *= self.ref_density
# We multiply by the inverse of \frac{\rho}{\mu}
m_multipliers[cell_index] = self.viscosity / density
c_entry = self.compressibility
c_entry *= self.porosities[cell_index]
c_entry /= self.delta_t
c_entry *= self.mesh.get_cell_volume(cell_index)
rhs_current[
self.mesh.get_number_of_faces() +
cell_index] += c_entry * self.current_pressure[cell_index]
self.lhs_coo.data[self.c_start + cell_index] = c_entry
for [index, cell_index] in enumerate(self.rate_wells):
rhs_current[self.mesh.get_number_of_faces()+cell_index] += \
self.rate_wells_rate[index]
self.mfd.update_m(self.lhs_coo.data[:self.m_x_coo_length],
m_multipliers)
solution = dsolve.spsolve(self.lhs_coo.tocsr(), rhs_current)
self.prev_pressure = self.current_pressure
self.current_pressure = solution[self.mesh.get_number_of_faces():]
self.current_velocity = solution[:self.mesh.get_number_of_faces()]
def SchurPCD2(Mass, L, F, backend):
Mass = Mass.sparray()
F = F.sparray()
L = L.sparray()
X = np.empty_like(Mass.todense())
print X.shape
Mass = Mass + 1e-4 * sp.identity(Mass.shape[0])
Mass = Mass.toarray()
print np.array(Mass[:, 0]).T
for i in range(X.shape[1]):
print Mass[i, :].T
X[i, :] = spsolve(F, Mass[:, i]) # print Schur.todense()
Schur = L * X
print Schur.diagonal()
if backend == "PETSc":
return PETSc.Mat().createAIJ(size=Schur.transpose().shape,
csr=(Schur.transpose().indptr,
Schur.transpose().indices,
Schur.transpose().data))
else:
return Schur.transpose()
def solveDiffusion(nx, ny, inputd):
# Create the DA and setup the problem
if inputd.kspType == 'sd':
U = 0.0
self = 0.0
[M, R, row, col, val] = build_A(inputd, self)
tic = PETSc.Log().getTime()
U = dsolve.spsolve(M, R, use_umfpack=True) #Direct solver
toc = PETSc.Log().getTime()
its = 1.0
rnorm = np.linalg.norm(M * U - R)
pde = 0.0
else:
da = PETSc.DA().create([nx, ny],
stencil_width=1,
boundary_type=('ghosted', 'ghosted'))
pde = diffusion2D(da)
pde.setupSolver(inputd)
print "Solving using", pde.solver_name
#Now solve
tic = PETSc.Log().getTime()
pde.solve(pde.b, pde.x)
toc = PETSc.Log().getTime()
its = pde.ksp.getIterationNumber()
rnorm = pde.ksp.getResidualNorm()
M = 0.0
U = M
# output performance/convergence information
time = toc - tic
timePerGrid = time / nx / ny
#rnorm = np.linalg.norm(M*U-R)
print "Nx Ny its ||r||_2 ElapsedTime (s) Elapsed Time/N_tot"
print nx, ny, its, rnorm, time, timePerGrid
return pde, time, timePerGrid, its, rnorm, U, M
def n_springs(N, f_vec):
"""
Compute the ratio $u_N/f_0$ for a chain
of $N$ springs. The range of frequencies
is given by $[f_{\min}, f_{\max}]$.
"""
nfreq = len(f_vec)
uf_ratio = np.zeros(nfreq)
for k, freq in enumerate(f_vec):
d_main = -2.0 * np.ones(N) + freq**2
d_main[0] = -1.0 + freq**2
d_main[-1] = -1.0 + freq**2
d_low = np.ones(N)
data = [d_low, d_main, d_low]
diags = [-1, 0, 1]
A = sparse.spdiags(data, diags, N, N, format='csc')
force = np.zeros(N)
force[0] = -1.0
x = dsolve.spsolve(A, force)
uf_ratio[k] = x[-1]
return uf_ratio
def test_new_gram(self):
self._check_for_empty_Data()
start = time.time()
print('making sparse gram')
self.sparse_gram = gram_Wendland_sparse(self, self.io.dir + '/Gram matrix') #only for COPAN Interpolant objects
print('finished sparse gram')
end_sparse = time.time()
print('making Gram with gram() function')
self.gram = gram(self)
print('finished gram')
end_gram = time.time()
print('making Gram with gram_Wendland function')
self.gram_Wendland = gram_Wendland(self)
print('finished gram_Wendland')
end_gram_Wendland = time.time()
print('Time for sparse: ', end_sparse - start)
print('Time for gram: ', end_gram - end_sparse)
print('Time for gram_Wendland: ', end_gram_Wendland - end_gram)
print('type(self.sparse_gram) = ', type(self.sparse_gram))
print('Difference in norm between gram and sparse_gram: ',
np.linalg.norm(self.gram - self.sparse_gram.toarray()))
print('Difference in norm between gram_Wendland and sparse_gram: ',
np.linalg.norm(self.gram_Wendland - self.sparse_gram.toarray()))
for data_object in self.data_points:
#self.dim = data_object.points.shape[0]
self.beta = np.hstack((self.beta, data_object.targets))
self.coefficients = np.linalg.solve(self.gram_Wendland, self.beta)
self.coefficients2 = spsolve(self.sparse_gram, self.beta)
print('Difference in coeffs between gram_Wendland and sparse_gram: ', np.linalg.norm(self.coefficients -
self.coefficients2))
def update_state(self):
Ah = self.Ah
J = self.J
self.calculate_f()
b = self.to1d(self.F)
u = dsolve.spsolve(Ah, b)
z = np.empty([J + 2, J + 2])
for i in range(0, J + 2):
for j in range(0, J + 2):
n = j + J * (i - 1) # Going from two indices to one
if i == 0 or i == J + 1:
z[i, j] = 0.0
if j == 0 or j == J + 1:
z[i, j] = 0.0
if i > 0 and j > 0 and i < J + 1 and j < J + 1:
z[i,
j] = u[n - 1] # elements of u are numbered starting at 0
self.state = z
def n_springs(N, f_vec):
"""
Compute the ratio $u_N/f_0$ for a chain
of $N$ springs. The range of frequencies
is given by $[f_{\min}, f_{\max}]$.
"""
nfreq = len(f_vec)
uf_ratio = np.zeros(nfreq)
for k, freq in enumerate(f_vec):
d_main = -2.0*np.ones(N) + freq**2
d_main[0] = -1.0 + freq**2
d_main[-1] = -1.0 + freq**2
d_low = np.ones(N)
data = [d_low, d_main, d_low]
diags = [-1,0,1]
A = sparse.spdiags(data, diags, N, N, format='csc')
force = np.zeros(N)
force[0] = -1.0
x = dsolve.spsolve(A, force)
uf_ratio[k] = x[-1]
return uf_ratio
def test_ndarray_support(self):
A = array([[1., 2.], [2., 0.]])
x = array([[1., 1.], [0.5, -0.5]])
b = array([[2., 0.], [2., 2.]])
assert_array_almost_equal(x, spsolve(A, b))
def SolPhaseField(FemInf,MatInf,MacroInf):
Node_xy = FemInf.Node_xy
Elem = FemInf.Elem
Hmax = FemInf.Hmax
GcI = MatInf.GcI
Lc = MatInf.Lc
Nnode = FemInf.Nnode
Nelem = FemInf.Nelem
NPE = FemInf.Npoint # Node Number per element
NGP = FemInf.Ngauss # Number of Gauss Point per element
w,r,s,t = QuadraturePoint()
Kg_irow = np.zeros((6*6*Nelem,),dtype = np.int)
Kg_icol = np.zeros((6*6*Nelem,),dtype = np.int)
Kg_V = np.zeros((6*6*Nelem,),dtype = np.float)
K_g_index = 0
Fn = np.zeros((Nnode),dtype=np.float)
for ielement in range(Nelem):
Node_xy_e = np.zeros((6,2),dtype=np.float)
for inode in range(NPE):
Node_xy_e[inode,:] = Node_xy[Elem[ielement,inode+1]-1,1:3]
Eldof = np.zeros((NPE,),dtype=np.int)
for inode in range(NPE):
Eldof[inode] = Elem[ielement,inode+1]-1
K1_e = np.zeros((6,6),dtype=np.float)
K2_e = np.zeros((6,6),dtype=np.float)
Fn_e = np.zeros((6,),dtype=np.float)
for igauss in range(NGP):
dNdr = np.array([[4.*r[igauss]-1., 0., -3.+4.*(r[igauss]+s[igauss]),
4.*s[igauss], -4.*s[igauss], 4.-8.*r[igauss]- 4.*s[igauss]],
[ 0., 4.*s[igauss]-1., -3.+4.*(r[igauss]+s[igauss]),
4.*r[igauss], 4.-4.*r[igauss]- 8.*s[igauss], -4.*r[igauss]]],dtype=np.float)
J = np.dot(dNdr,Node_xy_e)
detJ = J[0,0]*J[1,1]-J[1,0]*J[0,1]
invJ = np.array([[ J[1,1], -1.*J[0,1]],
[-1.*J[1,0], J[0,0]]])/detJ
dNdx = np.dot(invJ,dNdr)
Bs_e = dNdx
Ns_e = np.matrix([(2.*r[igauss]-1.)*r[igauss], (2.*s[igauss]-1.)*s[igauss], (2.*t[igauss]-1.)*t[igauss],
4.*r[igauss]*s[igauss], 4.*s[igauss]*t[igauss], 4.*t[igauss]*r[igauss]])
K1_e = K1_e + w[igauss]*detJ*(Ns_e.T*Ns_e)*(Hmax[ielement,igauss]+GcI/4./Lc)
Ndx=np.matrix(Bs_e[0,:])
Ndy=np.matrix(Bs_e[1,:])
K2_e = K2_e + w[igauss]*detJ*(Ndx.T*Ndx+Ndy.T*Ndy)*GcI*Lc
Fn_e = Fn_e + w[igauss]*detJ*1.*Hmax[ielement,igauss]*Ns_e
for i in range(6):
Fn[Eldof[i]] = Fn[Eldof[i]] + Fn_e[0,i]
for j in range(6):
Kg_irow[K_g_index] = Eldof[i]
Kg_icol[K_g_index] = Eldof[j]
Kg_V [K_g_index] = K1_e[i,j] + K2_e[i,j]
K_g_index = K_g_index + 1
K_g = sparse.coo_matrix((Kg_V,(Kg_irow,Kg_icol)),shape=(Nnode,Nnode))
K_g = K_g.tocsc()
Phase = dsolve.spsolve(K_g,Fn,use_umfpack=True)
FemInf.Phase = Phase
return FemInf
def update_pressure(self, time_step):
""" Solve the pressure system for p_o. self.current_p_o and
self.current_u_t are considered the pressure and velocity
at time n, and routine computes these quantities for time
n+1.
"""
# po_k, ut_k are the current newton iteration approximations
# to pressure and velocity.
po_k = np.array(self.current_p_o)
ut_k = np.array(self.current_u_t)
newton_residual = 100.
newton_step = 0
while abs(newton_residual > self.newton_threshold):
current_total_mobility = self.water_mobility(self.current_s_w, po_k)
current_total_mobility += self.oil_mobility(self.current_s_w, po_k)
current_total_mobility = 1./current_total_mobility
current_c_matrix = self.ref_density_water*self.current_s_w
current_c_matrix *= self.compressibility_water
current_c_matrix += self.ref_density_oil*(self.compressibility_oil
*(1.-self.current_s_w))
current_c_matrix *= self.porosities
current_c_matrix *= \
self.mesh.cell_volume[:self.mesh.get_number_of_cells()]
current_c_matrix /= self.delta_t
self.mfd.update_m(self.lhs_coo.data[:self.m_x_coo_length],
current_total_mobility)
for (cell_index, pressure_pi) in zip(self.pressure_wells,
self.pressure_wells_pi):
current_c_matrix[cell_index] += \
pressure_pi*1./current_total_mobility[cell_index]
self.lhs_coo.data[self.c_start:self.c_end] = current_c_matrix
lhs = self.lhs_coo.tocsr()
## J(x_n)(x_{n+1}-x_n) = -F(x_n)
## This line applies F(x_n)
ut_k_po_k_combo = np.concatenate((ut_k, po_k))
rhs = -self.mfd.build_rhs()
rhs += lhs.dot(ut_k_po_k_combo)
f2sum_l = np.ones(self.mesh.get_number_of_cells())
f2sum_l *= self.ref_density_water*self.current_s_w
f2sum_l *= self.porosities/self.delta_t
f2sum_l *= self.mesh.cell_volume[:self.mesh.get_number_of_cells()]
f2sum2_l = np.ones(self.mesh.get_number_of_cells())
f2sum2_l *= self.ref_density_oil
f2sum2_l *= 1.-self.current_s_w
f2sum2_l *= self.porosities/self.delta_t
f2sum2_l *= self.mesh.cell_volume[:self.mesh.get_number_of_cells()]
f2sum3_l = np.zeros(self.mesh.get_number_of_cells())
f2sum3_l += self.ref_density_water*(1.+self.compressibility_water*
(self.current_p_o))
f2sum3_l *= self.current_s_w
f2sum3_l += self.ref_density_oil*\
(1+self.compressibility_oil*self.current_p_o)*\
(1.-self.current_s_w)
f2sum3_l *= self.porosities/self.delta_t
f2sum3_l *= self.mesh.cell_volume[:self.mesh.get_number_of_cells()]
rhs[self.mfd.flux_dof:] += f2sum_l
rhs[self.mfd.flux_dof:] += f2sum2_l
rhs[self.mfd.flux_dof:] -= f2sum3_l
for (well_index, cell_index) in enumerate(self.rate_wells):
rhs[cell_index+self.mfd.flux_dof] += \
-self.get_well_rate_water(well_index)
rhs[cell_index+self.mfd.flux_dof] += \
-self.get_well_rate_oil(well_index)
for (cell_index, bhp, pressure_pi) in zip(self.pressure_wells,
self.pressure_wells_bhp,
self.pressure_wells_pi):
rhs[cell_index+self.mfd.flux_dof] -= \
pressure_pi*bhp*1./current_total_mobility[cell_index]
newton_residual = np.linalg.norm(rhs)/float(len(rhs))
if newton_residual > self.newton_threshold:
if self.solver == 0:
self.newton_solution = dsolve.spsolve(lhs, -rhs)
delta_po_k = self.newton_solution[self.mfd.flux_dof:]
delta_ut_k = self.newton_solution[:self.mfd.flux_dof]
if self.solver == 1:
self.mfd.update_m(self.m_coo.data, current_total_mobility)
m_csr = self.m_coo.tocsr()
self.m_petsc.createAIJWithArrays(size=m_csr.shape,
csr=(m_csr.indptr,
m_csr.indices,
m_csr.data))
self.m_petsc.setUp()
self.m_petsc.assemblyBegin()
self.m_petsc.assemblyEnd()
self.c_coo.data = current_c_matrix
c_csr = self.c_coo.tocsr()
self.c_petsc.createAIJWithArrays(
size=(self.mesh.get_number_of_cells(),
self.mesh.get_number_of_cells()),
csr=(c_csr.indptr,
c_csr.indices,
c_csr.data))
self.c_petsc.setUp()
self.c_petsc.assemblyBegin()
self.c_petsc.assemblyEnd()
m_diag = m_csr.diagonal()
m_diag = 1./m_diag
m_diag = sparse.csr_matrix((m_diag,
(list(range(self.mfd.flux_dof)),
list(range(self.mfd.flux_dof)))))
pc_matrix = -self.div_csr.dot(m_diag.dot(self.div_t_csr))
pc_matrix += c_csr
pc_matrix.sort_indices()
self.pc_petsc = PETSc.Mat()
self.pc_petsc.create(PETSc.COMM_WORLD)
self.pc_petsc.createAIJWithArrays(
size=(self.mesh.get_number_of_cells(),
self.mesh.get_number_of_cells()),
csr=(pc_matrix.indptr,
pc_matrix.indices,
pc_matrix.data))
self.pc_petsc.assemblyBegin()
self.pc_petsc.assemblyEnd()
self.schur_mat.set_c(self.c_petsc)
self.schur_mat.update_solver()
x, y = self.c_petsc.getVecs()
df1, f1 = self.m_petsc.getVecs()
f1.setArray(rhs[:self.mfd.flux_dof])
self.schur_mat.ksp.solve(f1, df1)
df1 = self.div_coo.dot(df1)
temp1, temp2 = self.c_petsc.getVecs()
temp1.setArray(np.ones(self.mesh.get_number_of_cells()))
self.schur_mat.mult(None, temp1, temp2)
x.setArray(df1-rhs[self.mfd.flux_dof:])
self.ksp.setOperators(self.schur_petsc, self.pc_petsc)
self.ksp.solve(x, y)
if newton_step == 1:
self.last_solution = np.array(y.getArray())
delta_po_k = y
f1_minvp, delta_ut_k = self.m_petsc.getVecs()
f1_minvp.setArray(-rhs[:self.mfd.flux_dof]-
self.div_t_coo.dot(y.getArray()))
self.schur_mat.ksp.solve(f1_minvp, delta_ut_k)
delta_po_k = delta_po_k.getArray()
delta_ut_k = delta_ut_k.getArray()
po_k += delta_po_k
ut_k += delta_ut_k
print("\t\t", newton_step, newton_residual)
newton_step += 1
if newton_step > self.newton_step_max:
1/0
self.previous_p_o = np.array(self.current_p_o)
self.previous_u_t = np.array(self.current_u_t)
self.current_p_o = po_k
self.current_u_t = ut_k
def fischer_newton(A, b, x, max_iter=0, tol_rel=0.00001, tol_abs=np.finfo(np.float64).eps*10, solver='perturbation', profile=True):
"""
Copyright 2012, Michael Andersen, DIKU, michael (at) diku (dot) dk
"""
# Human readable dictionary of exit messages
msg = {1 : 'preprocessing', # flag = 1
2 : 'iterating', # flag = 2
3 : 'relative', # flag = 3
4 : 'absolute', # flag = 4
5 : 'stagnation', # flag = 5
6 : 'local minima', # flag = 6
7 : 'nondescent', # flag = 7
8 : 'maxlimit', # flag = 8
}
# We use N as a reference for the usage of asserts throughout the
# program. We assume that everything is column vector of shape
# (N,1) if not the asserts will catch them.
N = np.size(b)
flag = 1
assert x.shape == (N,1), 'x0 is not a column vector, it has shape: ' + repr(x.shape)
assert A.shape == (N,N), 'A is not a square matrix, it has shape: ' + repr(A.shape)
assert b.shape == (N,1), 'b is not a column vector, it has shape: ' + repr(b.shape)
if max_iter == 0:
max_iter = np.floor(N/2.0)
# Ensure sane values
max_iter = max(max_iter,1)
# Rest of the value should be sane
##### Magic constants #####
h = 1e-7
alpha = 0.5
beta = 0.001
gamma = 1e-28
eps = np.finfo(np.float64).eps
rho = np.finfo(np.float64).eps
gmres_tol = 10*eps
##### Warm start of FN using Blocked Gauss-Seidel from PyAMG #####
warm_start = False
max_warm_iterate = 5
max_bgs_iterate = 5
if warm_start:
x = fischer_warm_start(A, x, b, max_warm_iterate, max_bgs_iterate)
##### Values needed file iterating #####
convergence = np.zeros(max_iter+1)
# Should use np.infty.
err = 1e20
iterate = 1
flag = 2
grad_steps = 0
grad_steps_max = max_iter
use_grad_steps = True
while iterate <= max_iter:
alpha = 0.5
take_grad_step = False
y = np.dot(A,x) + b
assert y.shape == (N,1), 'y is not a column vector, it has shape: ' + repr(y.shape)
assert np.all(np.isreal(y)), 'y is not real'
# Calculate the fischer function value
phi = fischer(y,x)
assert phi.shape == (N,1), 'phi is not a column vector, it has shape: ' + repr(phi.shape)
assert np.all(np.isreal(phi)), 'phi is not real'
old_err = err
# Calculate merit value, error
err = 0.5*np.dot(phi.T,phi)
assert err.shape == (1,1), 'err is not a scalar, it has shape: ' + repr(err.shape)
assert np.isreal(err), 'err is not real'
if profile:
convergence[iterate-1] = err
if grad_steps > grad_steps_max:
# Should we break or should we just stop using grad steps?
use_grad_steps = False
# flag = 10 # Number of grad steps exceeded.
# break
##### Test the stopping criterias used #####
rel_err = np.abs(err-old_err)/np.abs(old_err)
if rel_err < tol_rel:
if use_grad_steps:
take_grad_step = True
elif rel_err < eps:
flag = 3
break
if err < tol_abs:
flag = 4
break
##### Solving the Newton system
dx = np.zeros((N,1))
# Bitmask of True/False values where the conditions are
# satisfied, that is where phi and x are near
# singular/singular.
S = np.logical_and(np.abs(phi) < gamma, np.abs(x) < gamma)
# Bitmask of nonsingular values
I = np.logical_not(S)
idx = np.where(I)
restart = min(np.size(A,0), 10) # Number of iterates done
# before Restart for GMRES
# should restart
if 'random' == str.lower(solver): # Works on full system
# Initialize as sparse, otherwise indexing will not work.
J = sps.lil_matrix((N,N))
dx = sps.lil_matrix((N,1))
q = np.random.rand(N,1) / np.sqrt(2) - 1.0
p = np.random.rand(N,1) / np.sqrt(2) - 1.0
q[I] = (y[I]/((y[I]**2+x[I]**2)**(0.5)))-1
p[I] = (x[I]/((y[I]**2+x[I]**2)**(0.5)))-1
J[idx[0],idx[0]] = np.diag(p[I])*np.identity(A[idx].shape[0]) + np.dot(np.diag(q[I]),A[idx[0],:][:,idx[0]])
J = J.toarray()
# Call GMRES (This is very slow, might consider another
# approach)
dx[idx] = gmres(J[idx[0],:][:,idx[0]], (-phi[idx]), tol=gmres_tol, restart=restart)[0].reshape(idx[0].size,1)
dx = dx.toarray()
dx = dx.reshape(-1,1)
assert dx.shape == (N,1), 'dx is not a column vector, it has shape: ' + repr(dx.shape)
assert np.all(np.isreal(dx)), 'dx is not real'
##### Available methods from scipy #####
# bicg(A, b[, x0, tol, maxiter, xtype, M, ...]) Use BIConjugate Gradient iteration to solve A x = b
# bicgstab(A, b[, x0, tol, maxiter, xtype, M, ...]) Use BIConjugate Gradient STABilized iteration to solve A x = b
# cg(A, b[, x0, tol, maxiter, xtype, M, callback]) Use Conjugate Gradient iteration to solve A x = b
# cgs(A, b[, x0, tol, maxiter, xtype, M, callback]) Use Conjugate Gradient Squared iteration to solve A x = b
# gmres(A, b[, x0, tol, restart, maxiter, ...]) Use Generalized Minimal RESidual iteration to solve A x = b.
# lgmres(A, b[, x0, tol, maxiter, M, ...]) Solve a matrix equation using the LGMRES algorithm.
# minres(A, b[, x0, shift, tol, maxiter, ...]) Use MINimum RESidual iteration to solve Ax=b
# qmr(A, b[, x0, tol, maxiter, xtype, M1, M2, ...]) Use Quasi-Minimal Residual iteration to solve A x = b
elif 'perturbation' == str.lower(solver): # Works on full system
px = np.zeros(x.shape)
px[:] = x # Copy x
assert px.shape == (N,1), 'px is not a column vector, it has shape: ' + repr(px.shape)
assert np.all( np.isreal(px) ), 'px is not real'
direction = np.zeros(x.shape)
direction[:] = np.sign(x)
direction[ direction == 0 ] = 1
px[S] = gamma * direction[S]
p = np.zeros(px.shape)
p = (px / (np.sqrt(np.power(y,2) + np.power(px,2))))-1
assert p.shape == (N,1), 'p is not a column vector, it has shape: ' + repr(p.shape)
assert np.all(np.isreal(p)), 'p is not real'
q = np.zeros(y.shape)
q = (y / (np.sqrt(np.power(y,2) + np.power(px,2)))) - 1
assert q.shape == (N,1), 'q is not a column vector, it has shape: ' + repr(q.shape)
assert np.all(np.isreal(q)), 'q is not reeal'
J = np.dot(np.diag(p[:,0]),np.identity(N)) + np.dot(np.diag(q[:,0]),A)
assert J.shape == (N,N), 'J is not a square matrix, it has shape: ' + repr(J.shape)
assert np.all(np.isreal(J)), 'J is not real'
# Reciprocal conditioning number of J
rcond = 1/np.linalg.cond(J)
if np.isnan(rcond):
rcond = np.nan_to_num(rcond)
# Check conditioning of J, if bad use pinv to solve the system.
if rcond < 2*eps:
if np.any(np.isnan(J)):
print "J contains nan"
if np.any(np.isnan(phi)):
print "phi contains nan"
try:
dx = np.dot(spl.pinv(J), (-phi))
except Exception:
print repr(dir(Exception))
dx = np.dot(spl.pinv2(J), (-phi))
else:
J = sps.csc_matrix(J)
dx = dsolve.spsolve(J, (-phi), use_umfpack=True)
dx = dx.reshape(dx.size,1)
J = J.toarray()
assert dx.shape == (N,1), 'dx is not a column vector, it has shape: ' + repr(dx.shape)
assert np.all(np.isreal(dx)), 'dx is not real'
elif 'zero' == str.lower(solver):
J = sps.lil_matrix((N,N))
dx = sps.lil_matrix((N,1))
q = (y[I]/((y[I]**2+x[I]**2)**(0.5)))-1
p = (x[I]/((y[I]**2+x[I]**2)**(0.5)))-1
J[idx[0],idx[0]] = np.diag(p)*np.identity(A[idx].shape[0]) + np.dot(np.diag(q),A[idx[0],:][:,idx[0]])
J = J.toarray()
# Call GMRES (This is very slow, might consider another
# approach)
dx[idx] = gmres(J[idx[0],:][:,idx[0]], (-phi[idx]), tol=gmres_tol, restart=restart)[0].reshape(idx[0].size,1)
dx = dx.toarray()
dx = dx.reshape(-1,1)
assert dx.shape == (N,1), 'dx is not a column vector, it has shape: ' + repr(dx.shape)
elif 'approximation' == str.lower(solver):
### THIS IS NOT WORKING YET ###
J = sps.lil_matrix((N,N))
dx = sps.lil_matrix((N,1))
q = np.zeros(x.shape)
p = np.zeros(x.shape)
q[I] = y[I]/((y[I]**2+x[I]**2)**(0.5))-1
p[I] = x[I]/((y[I]**2+x[I]**2)**(0.5))-1
J[idx[0],idx[0]] = np.diag(p[I])*np.identity(A[idx].shape[0]) + np.dot(np.diag(q[I]),A[idx[0],:][:,idx[0]])
# Call GMRES, how do we handle a function handle for gmres?
fun = lambda dx: (fischer(np.dot(A[idx[0],:][:,idx[0]],(x[I]+dx[I]*h)) + b[I],x[I] + dx[I]*h) - phi[I]) / h
LO = LinearOperator((N,1), matvec = fun)
dx[idx] = gmres(LO, -phi[I], tol=gmres_tol, restart=restart)
# dx[idx] = gmres(fun, -phi[I], tol=1e-20, restart=restart)
else:
sys.stderr.write('Unknown solver method for Newton subsystem')
nabla_phi = np.dot(phi.T, J)
# We could use nabla_phi = nabla_phi.reshape(nabla_phi.size,
# 1) instead this creates a column vector no matter what.
nabla_phi = nabla_phi.T
assert nabla_phi.shape == (N,1), 'nabla_phi is not a column vector, it has shape: ' + repr(nabla_phi.shape)
assert np.all(np.isreal(nabla_phi)), 'nabla_phi is not real'
# Perform gradient descent step if take_grad_step is defined
if take_grad_step:
alpha = 0.9
dx = -nabla_phi
grad_steps += 1
# Tests whether the search direction is below machine
# precision.
if np.max(np.abs(dx)) < eps:
flag = 5
# If enabled and the relative change in error is low, use
# a gradient descent step
if take_grad_step:
dx = -nabla_phi
grad_steps += 1
print "*** Search direction below machine precision at iterate " + repr(iterate) + ", choosing gradient as search direction."
else:
break
# Test whether we are stuck in a local minima
if np.linalg.norm(nabla_phi) < tol_abs:
flag = 6
break
# Test whether our direction is a sufficient descent direction
if np.dot(nabla_phi.T,dx) > -rho*(np.dot(dx.T, dx)):
# Otherwise we should try gradient direction instead.
if use_grad_steps:
dx = -nabla_phi
grad_steps += 1
print "*** Non descend direction at iterate " + repr(iterate) + ", choosing gradient as search direction."
else:
flag = 7
break
##### Armijo backtracking combined with a projected line-search #####
tau = 1.0
f_0 = err
grad_f = beta*np.dot(nabla_phi.T,dx)
x_k = x[:]
assert x_k.shape == (N,1), 'x_k is not a column vector, it has shape: ' + repr(x_k)
assert np.all(np.isreal(x_k)), 'x_k is not real'
# Perform line search
while True:
x_k = np.maximum(0, x + dx*tau)
assert x_k.shape == (N,1), 'x_k is not a column vector, it has shape: ' + repr(x_k.shape)
assert np.all(np.isreal(x_k)), 'x_k is not real'
y_k = np.dot(A,x_k)+b
assert y_k.shape == (N,1), 'y_k is not a column vector, it has shape: ' + repr(y_k.shape)
assert np.all(np.isreal(y_k)), 'y_k is not real'
phi_k = fischer(y_k,x_k)
assert phi_k.shape == (N,1), 'phi_k is not a column vector, it has shape: ' + repr(phi_k.shape)
assert np.all(np.isreal(phi_k)), 'phi_k is not real'
f_k = 0.5*(np.dot(phi_k.T,phi_k))
# Test Armijo condition for sufficient decrease
if f_k <= f_0 + tau*grad_f:
break
# Test whether the stepsize has become too small
if tau*tau < gamma:
break
tau *= alpha
# Update iterate with result from line search.
x = x_k
assert x.shape == (N,1), 'x is not a column vector, it has shape: ' + repr(x.shape)
assert np.all(np.isreal(x)), 'x is not real.'
# Increment iterate
iterate +=1
if iterate >= max_iter:
iterate -= 1
flag = 8
print "No grad steps: " + repr(grad_steps)
return (x, err, iterate, flag, convergence[:iterate], msg[flag])
def test_singular(self):
A = csc_matrix((5, 5), dtype='d')
b = array([1, 2, 3, 4, 5], dtype='d')
x = spsolve(A, b, use_umfpack=False)
def test_ndarray_support(self):
A = array([[1., 2.], [2., 0.]])
x = array([[1., 1.], [0.5, -0.5]])
b = array([[2., 0.], [2., 2.]])
assert_array_almost_equal(x, spsolve(A, b))
