S0 = mfem.BilinearForm(x0_space)
S0.AddDomainIntegrator(mfem.DiffusionIntegrator(one))
S0.Assemble()
S0.EliminateEssentialBC(ess_bdr)
S0.Finalize()
matB0 = B0.SpMat()
matBhat = Bhat.SpMat()
matSinv = Sinv.SpMat()
matS0 = S0.SpMat()
# 8. Set up the 1x2 block Least Squares DPG operator, B = [B0 Bhat],
# the normal equation operator, A = B^t Sinv B, and
# the normal equation right-hand-size, b = B^t Sinv F.
B = mfem.BlockOperator(offsets_test, offsets)
B.SetBlock(0, 0, matB0)
B.SetBlock(0, 1, matBhat)
A = mfem.RAPOperator(B, matSinv, B)
SinvF = mfem.Vector(s_test)
matSinv.Mult(F,SinvF)
B.MultTranspose(SinvF, b)
# 9. Set up a block-diagonal preconditioner for the 2x2 normal equation
#
# [ S0^{-1} 0 ]
# [ 0 Shat^{-1} ] Shat = (Bhat^T Sinv Bhat)
#
# corresponding to the primal (x0) and interfacial (xhat) unknowns.
mVarf = mfem.BilinearForm(R_space)
bVarf = mfem.MixedBilinearForm(R_space, W_space)
mVarf.AddDomainIntegrator(mfem.VectorFEMassIntegrator(k))
mVarf.Assemble()
mVarf.Finalize()
M = mVarf.SpMat()
bVarf.AddDomainIntegrator(mfem.VectorFEDivergenceIntegrator())
bVarf.Assemble()
bVarf.Finalize()
B = bVarf.SpMat()
B *= -1
BT = mfem.Transpose(B)
darcyOp = mfem.BlockOperator(block_offsets)
darcyOp.SetBlock(0, 0, M)
darcyOp.SetBlock(0, 1, BT)
darcyOp.SetBlock(1, 0, B)
MinvBt = mfem.Transpose(B)
Md = mfem.Vector(M.Height())
M.GetDiag(Md)
for i in range(Md.Size()):
MinvBt.ScaleRow(i, 1 / Md[i])
S = mfem.Mult(B, MinvBt)
invM = mfem.DSmoother(M)
invS = mfem.GSSmoother(S)
invM.iterative_mode = False
invS.iterative_mode = False
from scipy.sparse import csr_matrix
if len(sys.argv) < 2:
import mfem.ser as mfem
elif sys.argv[1] == 'par':
import mfem.par as mfem
smat = csr_matrix([[1,2,3,], [0, 0, 1], [2, 0, 0]])
mmat = mfem.SparseMatrix(smat)
offset1 = mfem.intArray([0, 3, 6])
offset2 = mfem.intArray([0, 3, 6])
print('BlockOperator')
m = mfem.BlockOperator(offset1, offset2)
m.SetBlock(0, 0, mmat)
print(m._offsets[0].ToList())
print(m._offsets[1].ToList())
print(m._linked_op)
print('BlockOperator')
m = mfem.BlockOperator(offset1)
m.SetBlock(0, 1, mmat)
m.SetDiagonalBlock(1, mmat)
print(m._offsets.ToList())
print(m._linked_op)
print('BlockDiagonalPreconditioner')
m = mfem.BlockDiagonalPreconditioner(offset1)
m.SetDiagonalBlock(1, mmat)