def get_v_conv_conts(prev_v=None,
V=None,
invinds=None,
diribcs=None,
Picard=False):
""" get and condense the linearized convection
to be used in a Newton scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u + \
(u \\cdot \\nabla) u_0 - (u_0 \\cdot \\nabla) u_0
or in a Picard scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u
Parameters
----------
prev_v : (N,1) ndarray
convection velocity
V : dolfin.VectorFunctionSpace
FEM space of the velocity
invinds : (N,) ndarray or list
indices of the inner nodes
diribcs : list
of dolfin Dirichlet boundary conditons
Picard : boolean
whether Picard linearization is applied, defaults to `False`
Returns
-------
convc_mat : (N,N) sparse matrix
representing the linearized convection at the inner nodes
rhs_con : (N,1) array
representing :math:`(u_0 \\cdot \\nabla )u_0` at the inner nodes
rhsv_conbc : (N,1) ndarray
representing the boundary conditions
"""
N1, N2, rhs_con = dts.get_convmats(u0_vec=prev_v,
V=V,
invinds=invinds,
diribcs=diribcs)
if Picard:
convc_mat, rhsv_conbc = \
dts.condense_velmatsbybcs(N1, diribcs)
return convc_mat, 0 * rhs_con[invinds, ], rhsv_conbc
else:
convc_mat, rhsv_conbc = \
dts.condense_velmatsbybcs(N1 + N2, diribcs)
return convc_mat, rhs_con[invinds, ], rhsv_conbc
def get_v_conv_conts(prev_v=None, V=None, invinds=None, diribcs=None,
Picard=False):
""" get and condense the linearized convection
to be used in a Newton scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u + \
(u \\cdot \\nabla) u_0 - (u_0 \\cdot \\nabla) u_0
or in a Picard scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u
Parameters
----------
prev_v : (N,1) ndarray
convection velocity
V : dolfin.VectorFunctionSpace
FEM space of the velocity
invinds : (N,) ndarray or list
indices of the inner nodes
diribcs : list
of dolfin Dirichlet boundary conditons
Picard : boolean
whether Picard linearization is applied, defaults to `False`
Returns
-------
convc_mat : (N,N) sparse matrix
representing the linearized convection at the inner nodes
rhs_con : (N,1) array
representing :math:`(u_0 \\cdot \\nabla )u_0` at the inner nodes
rhsv_conbc : (N,1) ndarray
representing the boundary conditions
"""
N1, N2, rhs_con = dts.get_convmats(u0_vec=prev_v,
V=V,
invinds=invinds,
diribcs=diribcs)
if Picard:
convc_mat, rhsv_conbc = \
dts.condense_velmatsbybcs(N1, diribcs)
return convc_mat, 0*rhs_con[invinds, ], rhsv_conbc
else:
convc_mat, rhsv_conbc = \
dts.condense_velmatsbybcs(N1 + N2, diribcs)
return convc_mat, rhs_con[invinds, ], rhsv_conbc
def test_linearized_mat_NSE_form(self):
"""check the conversion: dolfin form <-> numpy arrays
and the linearizations"""
import dolfin_navier_scipy.dolfin_to_sparrays as dts
u = self.fenics_sol_u
u.t = 1.0
ufun = dolfin.project(u, self.V)
uvec = ufun.vector().get_local().reshape(len(ufun.vector()), 1)
N1, N2, fv = dts.get_convmats(u0_dolfun=ufun, V=self.V)
conv = dts.get_convvec(u0_dolfun=ufun, V=self.V)
self.assertTrue(np.allclose(conv, N1 * uvec))
self.assertTrue(np.allclose(conv, N2 * uvec))
def test_linearized_mat_NSE_form(self):
"""check the conversion: dolfin form <-> numpy arrays
and the linearizations"""
import dolfin_navier_scipy.dolfin_to_sparrays as dts
u = self.fenics_sol_u
u.t = 1.0
ufun = dolfin.project(u, self.V)
uvec = ufun.vector().get_local().reshape(len(ufun.vector()), 1)
N1, N2, fv = dts.get_convmats(u0_dolfun=ufun, V=self.V)
conv = dts.get_convvec(u0_dolfun=ufun, V=self.V)
self.assertTrue(np.allclose(conv, N1 * uvec))
self.assertTrue(np.allclose(conv, N2 * uvec))
def get_v_conv_conts(prev_v=None, V=None, invinds=None, diribcs=None,
dbcvals=None, dbcinds=None,
semi_explicit=False,
Picard=False, retparts=False, zerodiribcs=False):
""" get and condense the linearized convection
to be used in a Newton scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u + \
(u \\cdot \\nabla) u_0 - (u_0 \\cdot \\nabla) u_0
or in a Picard scheme
.. math::
(u \\cdot \\nabla) u \\to (u_0 \\cdot \\nabla) u
Parameters
----------
prev_v : (N,1) ndarray
convection velocity
V : dolfin.VectorFunctionSpace
FEM space of the velocity
invinds : (N,) ndarray or list
indices of the inner nodes
diribcs : list
of dolfin Dirichlet boundary conditons
Picard : Boolean
whether Picard linearization is applied, defaults to `False`
semi_explicit: Boolean, optional
whether to return minus the convection vector, and zero convmats
as needed for semi-explicit integration, defaults to `False`
retparts : Boolean, optional
whether to return both components of the matrices
and contributions to the rhs through the boundary conditions,
defaults to `False`
Returns
-------
convc_mat : (N,N) sparse matrix
representing the linearized convection at the inner nodes
rhs_con : (N,1) array
representing :math:`(u_0 \\cdot \\nabla )u_0` at the inner nodes
rhsv_conbc : (N,1) ndarray
representing the boundary conditions
"""
if semi_explicit:
rhs_con = dts.get_convvec(V=V, u0_vec=prev_v, diribcs=diribcs,
dbcinds=dbcinds, dbcvals=dbcvals,
invinds=invinds)
return 0., -rhs_con, 0.
N1, N2, rhs_con = dts.get_convmats(u0_vec=prev_v, V=V, invinds=invinds,
dbcinds=dbcinds, dbcvals=dbcvals,
diribcs=diribcs)
if zerodiribcs:
def _cndnsmts(mat, diribcs, **kw):
return mat[invinds, :][:, invinds], np.zeros((invinds.size, 1))
else:
_cndnsmts = dts.condense_velmatsbybcs
if Picard:
convc_mat, rhsv_conbc = _cndnsmts(N1, velbcs=diribcs,
dbcinds=dbcinds, dbcvals=dbcvals)
# return convc_mat, rhs_con[invinds, ], rhsv_conbc
return convc_mat, None, rhsv_conbc
elif retparts:
picrd_convc_mat, picrd_rhsv_conbc = _cndnsmts(N1, velbcs=diribcs,
dbcinds=dbcinds,
dbcvals=dbcvals)
anti_picrd_convc_mat, anti_picrd_rhsv_conbc = \
_cndnsmts(N2, velbcs=diribcs, dbcinds=dbcinds, dbcvals=dbcvals)
return ((picrd_convc_mat, anti_picrd_convc_mat),
rhs_con[invinds, ],
(picrd_rhsv_conbc, anti_picrd_rhsv_conbc))
else:
convc_mat, rhsv_conbc = _cndnsmts(N1+N2, velbcs=diribcs,
dbcinds=dbcinds, dbcvals=dbcvals)
return convc_mat, rhs_con[invinds, ], rhsv_conbc
def ass_convmat_asmatquad(W=None, invindsw=None):
""" assemble the convection matrix H, so that N(v)v = H[v.v]
note that the boundary conditions have to be treated properly
"""
mesh = W.mesh()
V = dolfin.FunctionSpace(mesh, 'CG', 2)
# this is very specific for V being a 2D VectorFunctionSpace
invindsv = invindsw[::2]/2
v = dolfin.TrialFunction(V)
vt = dolfin.TestFunction(V)
w = dolfin.TrialFunction(W)
wt = dolfin.TestFunction(W)
def _pad_csrmats_wzerorows(smat, wheretoput='before'):
"""add zero rows before/after each row
"""
indpeter = smat.indptr
auxindp = np.c_[indpeter, indpeter].flatten()
if wheretoput == 'after':
smat.indptr = auxindp[1:]
else:
smat.indptr = auxindp[:-1]
smat._shape = (2*smat.shape[0], smat.shape[1])
return smat
def _shuff_mrg_csrmats(xm, ym):
"""shuffle merge csr mats [xxx],[yyy] -> [xyxyxy]
"""
xm.indices = 2*xm.indices
ym.indices = 2*ym.indices + 1
xm._shape = (xm.shape[0], 2*xm.shape[1])
ym._shape = (ym.shape[0], 2*ym.shape[1])
return xm + ym
nklist = []
for i in invindsv:
# for i in range(V.dim()):
# iterate for the columns
bi = dolfin.Function(V)
bvec = np.zeros((V.dim(), ))
bvec[i] = 1
bi.vector()[:] = bvec
nxi = dolfin.assemble(v * bi.dx(0) * vt * dx)
nyi = dolfin.assemble(v * bi.dx(1) * vt * dx)
rows, cols, values = nxi.data()
nxim = sps.csr_matrix((values, cols, rows))
rows, cols, values = nyi.data()
nyim = sps.csr_matrix((values, cols, rows))
nxyim = _shuff_mrg_csrmats(nxim, nyim)
nxyim = nxyim[invindsv, :][:, invindsw]
nyxxim = _pad_csrmats_wzerorows(nxyim.copy(), wheretoput='after')
nyxyim = _pad_csrmats_wzerorows(nxyim.copy(), wheretoput='before')
nklist.extend([nyxxim, nyxyim])
hmat = sps.hstack(nklist, format='csc')
xexp = '(1-x[0])*x[0]*(1-x[1])*x[1]*x[0]*0'
yexp = '(1-x[0])*x[0]*(1-x[1])*x[1]*x[1]+1'
# yexp = 'x[0]*x[0]*x[1]*x[1]'
f = dolfin.Expression((xexp, yexp))
u = dolfin.interpolate(f, W)
uvec = np.atleast_2d(u.vector().array()).T
uvec_gamma = uvec.copy()
uvec_gamma[invindsw] = 0
u_gamma = dolfin.Function(W)
u_gamma.vector().set_local(uvec_gamma)
uvec_i = 0*uvec
uvec_i[invindsw, :] = uvec[invindsw]
u_i = dolfin.Function(W)
u_i.vector().set_local(uvec_i)
# Assemble the 'actual' form
nform = dolfin.assemble(inner(grad(w) * u, wt) * dx)
rows, cols, values = nform.data()
nmat = sps.csr_matrix((values, cols, rows))
nmatrc = nmat[invindsw, :][:, :]
# nmatrccc = nmatrc[:, :][:, invindsw]
# nmatc = nmat[invindsw, :][:, :]
N1, N2, fv = dnsts.get_convmats(u0_dolfun=u_gamma, V=W)
# print np.linalg.norm(nmatc * uvec[invindsw])
print np.linalg.norm(nmatrc * uvec)
print np.linalg.norm(nmatrc * uvec_i + nmatrc * uvec_gamma)
print np.linalg.norm(hmat * np.kron(uvec[invindsw], uvec[invindsw])
+ ((N1+N2)*uvec_i)[invindsw, :] + fv[invindsw, :])
# print np.linalg.norm((hmat * np.kron(uvec, uvec))[invindsw, :])
# print np.linalg.norm(((N1+N2)*uvec)[invindsw, :] + fv[invindsw, :])
print 'consistency tests'
print np.linalg.norm(uvec[invindsw]) - np.linalg.norm(uvec_i)
print np.linalg.norm(uvec - uvec_gamma - uvec_i)