def test_fullPatch(self): NWorldCoarse = np.array([3,3]) NCoarseElement = np.array([2,2]) world = World(NWorldCoarse, NCoarseElement) k = 3 patchT = [Patch(world, k, TInd) for TInd in range(world.NtCoarse)] basisCorrectorsListT = [[np.zeros(world.NpFine), np.zeros(world.NpFine), np.zeros(world.NpFine), np.zeros(world.NpFine)] for i in range(world.NtCoarse)] # Set first and last corrector to constant 1 and 2 basisCorrectorsListT[0][0][:] = 1 basisCorrectorsListT[-1][-1][:] = 2 basisCorrectors = pglod.assembleBasisCorrectors(world, patchT, basisCorrectorsListT) self.assertTrue(np.allclose(basisCorrectors.todense()[:,0], 1)) self.assertTrue(np.allclose(basisCorrectors.todense()[:,-1], 2))
def test_smallPatch(self): NWorldCoarse = np.array([3,3]) NCoarseElement = np.array([2,2]) world = World(NWorldCoarse, NCoarseElement) k = 0 patchT = [Patch(world, k, TInd) for TInd in range(world.NtCoarse)] basisCorrectorsListT = [[np.zeros(patchT[0].NpFine), np.zeros(patchT[0].NpFine), np.zeros(patchT[0].NpFine), np.zeros(patchT[0].NpFine)] for i in range(world.NtCoarse)] # Set first and last corrector to constant 1 and 2 basisCorrectorsListT[0][0][:] = 1 basisCorrectorsListT[-1][-1][:] = 2 basisCorrectors = pglod.assembleBasisCorrectors(world, patchT, basisCorrectorsListT) firstBasisCorrectorShouldBe = np.array([1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]) lastBasisCorrectorShouldBe = np.array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 0, 0, 0, 0, 2, 2, 2, 0, 0, 0, 0, 2, 2, 2]) self.assertTrue(np.allclose(basisCorrectors.todense()[:,0].squeeze(), firstBasisCorrectorShouldBe)) self.assertTrue(np.allclose(basisCorrectors.todense()[:,-1].squeeze(), lastBasisCorrectorShouldBe))
print() print('computing real right hand side correctors', end='', flush=True) patchT, correctorRhsT, RmsiT, cetaTPrimeT = zip(*map(real_computeRmsi, range(world.NtCoarse))) print() KFull = pglod.assembleMsStiffnessMatrix(world, patchT, KmsijT) RFull = pglod.assemblePatchFunction(world, patchT, RmsiT) MFull = fem.assemblePatchMatrix(world.NWorldFine, world.MLocFine) Rf = pglod.assemblePatchFunction(world, patchT, correctorRhsT) basis = fem.assembleProlongationMatrix(world.NWorldCoarse, world.NCoarseElement) bFull = basis.T * MFull * f_trans - RFull basisCorrectors = pglod.assembleBasisCorrectors(world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors uFull, _ = pglod.solve(world, KFull, bFull, boundaryConditions) uLodFine = modifiedBasis * uFull uLodFine += Rf u_best_LOD = uLodFine energy_norm = np.sqrt(np.dot(u_best_LOD, AFine_trans * u_best_LOD)) energy_error = np.sqrt(np.dot((uFineFull_trans - u_best_LOD), AFine_trans * (uFineFull_trans - u_best_LOD))) print("Energy norm {}, error {}, rel. error {}".format(energy_norm, energy_error, energy_error/energy_norm)) # Use mapper to distribute computations (mapper could be the 'map' built-in or e.g. an ipyparallel map)
def Monte_Carlo_simulation(): print('Computing Monte Carlo step') global aFine_ref global aFine_trans global aFine_pert global k global KmsijT global correctorsListT aFine_ref = aFine_ref_shaped.flatten() psi, cq1 = create_psi_function() # plt.figure('domain mapping') # plt.plot(np.arange(0, fine + 1), cq1[0, :], label='$id(x) - \psi(x)$') # plt.plot(np.arange(0, fine), ref_array * 0.01) # plt.title('Domain mapping') # plt.legend() xpFine_pert = psi.evaluate(xpFine) xpFine_ref = psi.inverse_evaluate(xpFine) xtFine_pert = psi.evaluate(xtFine) xtFine_ref = psi.inverse_evaluate(xtFine) aFine_pert = func.evaluateDQ0(NFine, aFine_ref, xtFine_ref) aBack_ref = func.evaluateDQ0(NFine, aFine_pert, xtFine_pert) print('Psi is invertible if this is zero: {}'.format( np.linalg.norm(aBack_ref - aFine_ref))) every_psi_was_valid.append(np.linalg.norm(aBack_ref - aFine_ref)) #aFine_trans is the transformed perturbed reference coefficient aFine_trans = np.einsum('tji, t, tkj, t -> tik', psi.Jinv(xtFine), aFine_ref, psi.Jinv(xtFine), psi.detJ(xtFine)) f_pert = np.ones(np.prod(NFine + 1)) f_ref = func.evaluateCQ1(NFine, f_pert, xpFine_pert) f_trans = np.einsum('t, t -> t', f_ref, psi.detJ(xpFine)) uFineFull_pert, AFine_pert, MFine = femsolver.solveFine( world, aFine_pert, f_pert, None, boundaryConditions) uFineFull_trans, AFine_trans, _ = femsolver.solveFine( world, aFine_trans, f_trans, None, boundaryConditions) uFineFull_trans_pert = func.evaluateCQ1(NFine, uFineFull_trans, xpFine_ref) energy_norm = np.sqrt(np.dot(uFineFull_pert, AFine_pert * uFineFull_pert)) energy_error = np.sqrt( np.dot((uFineFull_trans_pert - uFineFull_pert), AFine_pert * (uFineFull_trans_pert - uFineFull_pert))) print("Energy norm {}, error {}, rel. error {}".format( energy_norm, energy_error, energy_error / energy_norm)) Aeye = np.tile(np.eye(2), [np.prod(NFine), 1, 1]) aFine_ref = np.einsum('tji, t-> tji', Aeye, aFine_ref) print('compute domain mapping error indicators') epsFine, epsCoarse = zip(*map(computeIndicators, range(world.NtCoarse))) print('apply tolerance') Elements_to_be_updated = [] TOL = 0.1 for i in range(world.NtCoarse): if epsFine[i] >= TOL: Elements_to_be_updated.append(i) print('.... to be updated for domain mapping: {}%'.format( np.size(Elements_to_be_updated) / np.size(epsFine) * 100)) print('update correctors') if np.size(Elements_to_be_updated) == 0: correctorsListTNew, KmsijTNew = correctorsListT, KmsijT else: patchT_irrelevant, correctorsListTNew, KmsijTNew, csiTNew = zip( *map(UpdateCorrectors, Elements_to_be_updated)) KmsijT_list = list(KmsijT) correctorsListT_list = list(correctorsListT) i = 0 for T in Elements_to_be_updated: KmsijT_list[T] = KmsijTNew[i] correctorsListT_list[T] = correctorsListTNew[i] i += 1 KmsijT = tuple(KmsijT_list) correctorsListT = tuple(correctorsListT_list) print('solve the system') KFull = pglod.assembleMsStiffnessMatrix(world, patchT, KmsijT) MFull = fem.assemblePatchMatrix(NFine, world.MLocFine) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) basisCorrectors = pglod.assembleBasisCorrectors(world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors bFull = MFull * f_trans bFull = basis.T * bFull uFull, _ = pglod.solve(world, KFull, bFull, boundaryConditions) uLodFine = modifiedBasis * uFull uLodFine_METHOD = uLodFine newErrorFine = np.sqrt( np.dot(uLodFine - uFineFull_trans, AFine_trans * (uLodFine - uFineFull_trans))) print('Method error: {}'.format(newErrorFine)) print('update all correctors') patchT_irrelevant, correctorsListT, KmsijT, csiTNew = zip( *map(UpdateCorrectors, range(world.NtCoarse))) print('solve the system') KFull = pglod.assembleMsStiffnessMatrix(world, patchT, KmsijT) MFull = fem.assemblePatchMatrix(NFine, world.MLocFine) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) basisCorrectors = pglod.assembleBasisCorrectors(world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors bFull = MFull * f_trans bFull = basis.T * bFull uFull, _ = pglod.solve(world, KFull, bFull, boundaryConditions) uLodFine = modifiedBasis * uFull newErrorFine = np.sqrt( np.dot(uLodFine - uFineFull_trans, AFine_trans * (uLodFine - uFineFull_trans))) print('Exact LOD error: {}'.format(newErrorFine)) return uLodFine_METHOD, uLodFine, uFineFull_pert, MFine
def test_1d_core(mapper): # Example from Peterseim, Variational Multiscale Stabilization and the Exponential Decay of correctors, p. 2 # Two modifications: A with minus and u(here) = 1/4*u(paper). NFine = np.array([3200]) NpFine = np.prod(NFine + 1) NList = [10, 20, 40, 80, 160] epsilon = 1. / 320 k = 2 pi = np.pi xt = util.tCoordinates(NFine).flatten() xp = util.pCoordinates(NFine).flatten() aFine = (2 - np.cos(2 * pi * xt / epsilon))**(-1) uSol = 4 * (xp - xp**2) - 4 * epsilon * ( 1 / (4 * pi) * np.sin(2 * pi * xp / epsilon) - 1 / (2 * pi) * xp * np.sin(2 * pi * xp / epsilon) - epsilon / (4 * pi**2) * np.cos(2 * pi * xp / epsilon) + epsilon / (4 * pi**2)) uSol = uSol / 4 previousErrorCoarse = np.inf previousErrorFine = np.inf for N in NList: NWorldCoarse = np.array([N]) NCoarseElement = NFine // NWorldCoarse boundaryConditions = np.array([[0, 0]]) world = World(NWorldCoarse, NCoarseElement, boundaryConditions) xpCoarse = util.pCoordinates(NWorldCoarse).flatten() def computeKmsij(TInd): patch = Patch(world, k, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) correctorsList = lod.computeBasisCorrectors( patch, IPatch, aPatch) csi = lod.computeBasisCoarseQuantities( patch, correctorsList, aPatch) return patch, correctorsList, csi.Kmsij # Use mapper to distribute computations (mapper could be the 'map' built-in or e.g. an ipyparallel map) patchT, correctorsListT, KmsijT = zip( *mapper(computeKmsij, range(world.NtCoarse))) KFull = pglod.assembleMsStiffnessMatrix(world, patchT, KmsijT) MFull = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) free = util.interiorpIndexMap(NWorldCoarse) f = np.ones(world.NpCoarse) bFull = MFull * f KFree = KFull[free][:, free] bFree = bFull[free] xFree = sparse.linalg.spsolve(KFree, bFree) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) basisCorrectors = pglod.assembleBasisCorrectors( world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors xFull = np.zeros(world.NpCoarse) xFull[free] = xFree uLodCoarse = basis * xFull uLodFine = modifiedBasis * xFull AFine = fem.assemblePatchMatrix(NFine, world.ALocFine, aFine) MFine = fem.assemblePatchMatrix(NFine, world.MLocFine) newErrorCoarse = np.sqrt( np.dot(uSol - uLodCoarse, MFine * (uSol - uLodCoarse))) newErrorFine = np.sqrt( np.dot(uSol - uLodFine, AFine * (uSol - uLodFine))) self.assertTrue(newErrorCoarse < previousErrorCoarse) self.assertTrue(newErrorFine < previousErrorFine)
def helmholtz_nonlinear_adaptive(mapper, fineLvl, coarseLvl, maxit): fineExp = fineLvl NFine = np.array([2**fineLvl, 2**fineLvl]) NpFine = np.prod(NFine + 1) N = 2**coarseLvl tolList = [2.0, 1.0, 0.5, 0.25, 0.125, 0.0625, 0.] ell = 2 # localization parameter k = 15. # wavenumber maxit_Fine = 200 xt = util.tCoordinates(NFine) xp = util.pCoordinates(NFine) # multiscale coefficients on the scale NFine-2 np.random.seed(444) sizeK = np.size(xt[:, 0]) nFine = NFine[0] # determine domain D_eps = supp(1-n) = supp(1-A) (all equal for the moment) indicesIn = (xt[:, 0] > 0.15) & (xt[:, 0] < 0.85) & (xt[:, 1] > 0.15) & ( xt[:, 1] < 0.85) indicesInEps = (xt[:, 0] > 0.15) & (xt[:, 0] < 0.85) & ( xt[:, 1] > 0.15) & (xt[:, 1] < 0.85) # coefficients aFine = np.ones(xt.shape[0]) cn = .05 # lower bound on n Cn = 1. # upper bound on n nEpsPro = coeffi(xt[:, 0], xt[:, 1], fineLvl) k2Fine = k**2 * np.ones(xt.shape[0]) k2Fine[indicesIn] = k**2 * ((Cn - cn) * nEpsPro[indicesIn] + cn) kFine = k * np.ones(xt.shape[0]) Ceps = 0.3 # upper bound on eps (lower bound is 0) epsEpsPro = np.ones(sizeK) epsFine = np.zeros(xt.shape[0]) epsFine[indicesInEps] = Ceps * epsEpsPro[indicesInEps] # 0 OR Ceps plotC = np.ones(sizeK) plotC[indicesIn] = nEpsPro[indicesIn] drawCoefficient(NFine, plotC) xC = xp[:, 0] yC = xp[:, 1] # define right-hand side and boundary condition def funcF(x, y): res = 100 * np.ones(x.shape, dtype='complex128') return res f = funcF(xC, yC) # reference solution uSol = np.zeros(NpFine, dtype='complex128') # boundary conditions boundaryConditions = np.array([[1, 1], [1, 1]]) worldFine = World(NFine, np.array([1, 1]), boundaryConditions) # fine matrices BdFineFEM = fem.assemblePatchBoundaryMatrix( NFine, fem.localBoundaryMassMatrixGetter(NFine)) MFineFEM = fem.assemblePatchMatrix(NFine, fem.localMassMatrix(NFine)) KFineFEM = fem.assemblePatchMatrix( NFine, fem.localStiffnessMatrix(NFine)) # , aFine) kBdFine = fem.assemblePatchBoundaryMatrix( NFine, fem.localBoundaryMassMatrixGetter(NFine), kFine) KFine = fem.assemblePatchMatrix(NFine, fem.localStiffnessMatrix(NFine), aFine) print('***computing reference solution***') uOldFine = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit_Fine): print('-- itFine = %d' % it) knonlinUpreFine = np.abs(uOldFine) knonlinUFine = func.evaluateCQ1(NFine, knonlinUpreFine, xt) k2FineUfine = np.copy(k2Fine) k2FineUfine[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinUFine[indicesInEps]**2 ) # full coefficient, including nonlinearity k2MFine = fem.assemblePatchMatrix( NFine, fem.localMassMatrix(NFine), k2FineUfine) # weighted mass matrix, updated in every iteration nodesFine = np.arange(worldFine.NpFine) fixFine = util.boundarypIndexMap(NFine, boundaryConditions == 0) freeFine = np.setdiff1d(nodesFine, fixFine) # right-hand side fhQuad = MFineFEM * f # fine system lhsh = KFine[freeFine][:, freeFine] - k2MFine[ freeFine][:, freeFine] + 1j * kBdFine[freeFine][:, freeFine] rhsh = fhQuad[freeFine] xFreeFine = sparse.linalg.spsolve(lhsh, rhsh) xFullFine = np.zeros(worldFine.NpFine, dtype='complex128') xFullFine[freeFine] = xFreeFine uOldFine = np.copy(xFullFine) # residual - used as stopping criterion knonlinU = np.abs(uOldFine) knonlinUFineIt = func.evaluateCQ1(NFine, knonlinU, xt) k2FineUfineIt = np.copy(k2Fine) k2FineUfineIt[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinUFineIt[indicesInEps]**2 ) # update full coefficient, including nonlinearity k2MFineIt = fem.assemblePatchMatrix(NFine, fem.localMassMatrix(NFine), k2FineUfineIt) Ares = KFine - k2MFineIt + 1j * kBdFine residual = np.linalg.norm(Ares * xFullFine - fhQuad) / np.linalg.norm( Ares * xFullFine) print('---- residual = %.4e' % residual) if residual < 1e-12: break # stopping criterion uSol = xFullFine # final fine reference solution print('***reference solution computed***\n') counter = 0 # for figures print('***computing multiscale approximations***') relErrEnergy = np.zeros([len(tolList), maxit]) for tol in tolList: counter += 1 print('H = %.4e, tol = %.4e' % (1. / N, tol)) NWorldCoarse = np.array([N, N]) NCoarseElement = NFine // NWorldCoarse world = World(NWorldCoarse, NCoarseElement, boundaryConditions) NpCoarse = np.prod(NWorldCoarse + 1) uOldUps = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit): print('-- it = %d:' % it) knonlinUpre = np.abs(uOldUps) knonlinU = func.evaluateCQ1(NFine, knonlinUpre, xt) k2FineU = np.copy(k2Fine) k2FineU[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinU[indicesInEps]**2) print('---- starting computation of correctors') def computeLocalContribution(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def computeIndicators(TInd): k2FineUPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineU) k2FineUOldPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineUOld) E_vh = lod.computeErrorIndicatorCoarse_helmholtz( patchT[TInd], muTPrime[TInd], k2FineUOldPatch, k2FineUPatch) return E_vh def UpdateCorrectors(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def UpdateElements(tol, E, Kmsij_old, Mmsij_old, Bdmsij_old, correctors_old, mu_old): print('---- apply tolerance') Elements_to_be_updated = [] for (i, eps) in E.items(): if eps > tol * k**2: Elements_to_be_updated.append(i) if len(E) > 0: print( '---- percentage of non-zero element correctors to be updated: %.4f' % (100 * np.size(Elements_to_be_updated) / len(E)), flush=True) print( '---- total percentage of element correctors to be updated: %.4f' % (100 * np.size(Elements_to_be_updated) / len(mu_old)), flush=True) print('---- update local contributions') KmsijT_list = list(np.copy(Kmsij_old)) MmsijT_list = list(np.copy(Mmsij_old)) BdmsijT_list = list(np.copy(Bdmsij_old)) muT_list = np.copy(mu_old) for T in np.setdiff1d(range(world.NtCoarse), Elements_to_be_updated): patch = Patch(world, ell, T) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctors_old[T], aPatch, kPatch, k2Patch) KmsijT_list[T] = csi.Kmsij MmsijT_list[T] = csi.Mmsij BdmsijT_list[T] = csi.Bdmsij muT_list[T] = csi.muTPrime if np.size(Elements_to_be_updated) != 0: #print('---- update correctors') patchT_irrelevant, correctorsListTNew, KmsijTNew, MmsijTNew, BdmsijTNew, muTPrimeNew = zip( *mapper(UpdateCorrectors, Elements_to_be_updated)) #print('---- update correctorsList') correctorsListT_list = list(np.copy(correctors_old)) i = 0 for T in Elements_to_be_updated: KmsijT_list[T] = KmsijTNew[i] correctorsListT_list[T] = correctorsListTNew[i] MmsijT_list[T] = MmsijTNew[i] BdmsijT_list[T] = BdmsijTNew[i] muT_list[T] = muTPrimeNew[i] i += 1 KmsijT = tuple(KmsijT_list) correctorsListT = tuple(correctorsListT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime else: KmsijT = tuple(KmsijT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctors_old, KmsijT, MmsijT, BdmsijT, muTPrime if it == 0: patchT, correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = zip( *mapper(computeLocalContribution, range(world.NtCoarse))) else: E_vh = list(mapper(computeIndicators, range(world.NtCoarse))) print( '---- maximal value error estimator for basis correctors {}' .format(np.max(E_vh))) E = {i: E_vh[i] for i in range(np.size(E_vh)) if E_vh[i] > 0} # loop over elements with possible recomputation of correctors correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = UpdateElements( tol, E, KmsijT, MmsijT, BdmsijT, correctorsListT, muTPrime) # tol scaled by maximal error indicator print('---- finished computation of correctors') KLOD = pglod.assembleMsStiffnessMatrix( world, patchT, KmsijT) # ms stiffness matrix k2MLOD = pglod.assembleMsStiffnessMatrix(world, patchT, MmsijT) # ms mass matrix kBdLOD = pglod.assembleMsStiffnessMatrix( world, patchT, BdmsijT) # ms boundary matrix MFEM = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) BdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse)) print('---- coarse matrices assembled') nodes = np.arange(world.NpCoarse) fix = util.boundarypIndexMap(NWorldCoarse, boundaryConditions == 0) free = np.setdiff1d(nodes, fix) assert (nodes.all() == free.all()) # compute global interpolation matrix patchGlobal = Patch(world, NFine[0] + 2, 0) IH = interp.L2ProjectionPatchMatrix(patchGlobal, boundaryConditions) assert (IH.shape[0] == NpCoarse) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) fHQuad = basis.T * MFineFEM * f print('---- solving coarse system') # coarse system lhsH = KLOD[free][:, free] - k2MLOD[ free][:, free] + 1j * kBdLOD[free][:, free] rhsH = fHQuad[free] xFree = sparse.linalg.spsolve(lhsH, rhsH) basisCorrectors = pglod.assembleBasisCorrectors( world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors xFull = np.zeros(world.NpCoarse, dtype='complex128') xFull[free] = xFree uLodCoarse = basis * xFull uLodFine = modifiedBasis * xFull uOldUps = np.copy(uLodFine) k2FineUOld = np.copy(k2FineU) Err = np.sqrt( np.dot((uSol - uLodFine).conj(), KFineFEM * (uSol - uLodFine)) + k**2 * np.dot((uSol - uLodFine).conj(), MFineFEM * (uSol - uLodFine))) ErrEnergy = Err / np.sqrt( np.dot((uSol).conj(), KFineFEM * (uSol)) + k**2 * np.dot((uSol).conj(), MFineFEM * (uSol))) print('---- ', np.abs(ErrEnergy), '\n***********************************************') # save errors in arrays relErrEnergy[counter - 1, it] = ErrEnergy print('\n') its = np.arange(1, maxit + 1) plt.figure(1) plt.title( 'Relative energy errors w.r.t iterations for different tolerances - Ex 3' ) plt.plot(its, relErrEnergy[0, :], 'x--', color='black', label='tol = 2') plt.plot(its, relErrEnergy[1, :], 'x-', color='blue', label='tol = 1') plt.plot(its, relErrEnergy[2, :], 'x-', color='green', label='tol = 0.5') plt.plot(its, relErrEnergy[3, :], 'x-', color='orange', label='tol = 0.25') plt.plot(its, relErrEnergy[4, :], 'x-', color='red', label='tol = 0.125') plt.plot(its, relErrEnergy[5, :], 'x-', color='magenta', label='tol = 0.0625') plt.plot(its, relErrEnergy[6, :], 'x--', color='black', label='tol = 0') plt.yscale('log') plt.legend() plt.show()
def StartAlgorithm(self): assert (self.init) # only start the algorithm once # in case not every element is affected, the percentage would be missleading. eps_size = np.size(self.E_vh) self.E_vh = { i: self.E_vh[i] for i in range(np.size(self.E_vh)) if self.E_vh[i] > 0 } full_percentage = len(self.E_vh) / eps_size world = self.world print('starting algorithm ...... ') TOLt = [] to_be_updatedT = [] energy_errorT = [] rel_energy_errorT = [] tmp_errorT = [] offset = [] TOL = 100 # not relevant for i in range(len(self.E_vh) + 1): if self.init: pass else: offset = self.UpdateNextElement(offset, Printing=False) if self.init: to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated) pass else: to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated * full_percentage) KFull = pglod.assembleMsStiffnessMatrix(world, self.patchT, self.KmsijT) RFull = pglod.assemblePatchFunction(world, self.patchT, self.RmsijT) Rf = pglod.assemblePatchFunction(world, self.patchT, self.correctorsRhsT) basis = fem.assembleProlongationMatrix(world.NWorldCoarse, world.NCoarseElement) bFull = basis.T * self.MFull * self.f_trans - RFull basisCorrectors = pglod.assembleBasisCorrectors( world, self.patchT, self.correctorsListT) modifiedBasis = basis - basisCorrectors uFull, _ = pglod.solve(world, KFull, bFull, self.boundaryConditions) uLodFine = modifiedBasis * uFull uLodFine += Rf uFineFull_trans_LOD = uLodFine if self.init: uFineFull_trans_LOD_old = uLodFine energy_norm = np.sqrt( np.dot(uFineFull_trans_LOD, self.AFine_trans * uFineFull_trans_LOD)) # tmp_error tmp_energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - uFineFull_trans_LOD_old), self.AFine_trans * (uFineFull_trans_LOD - uFineFull_trans_LOD_old))) # actual error if self.compare_with_best_LOD: energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - self.u_best_LOD), self.AFine_trans * (uFineFull_trans_LOD - self.u_best_LOD))) else: energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - self.uFineFull_trans), self.AFine_trans * (uFineFull_trans_LOD - self.uFineFull_trans))) uFineFull_trans_LOD_old = uFineFull_trans_LOD if self.init: self.init = 0 print( ' step({:3d}/{}) T: {} updates: {:7.3f}%, energy error: {:f}, tmp_error: {:f}, relative energy error: {:f}' .format(i, len(self.E_vh), ' - ', to_be_updated * full_percentage, energy_error, tmp_energy_error, energy_error / energy_norm)) else: print( ' step({:3d}/{}) T: {:3d} updates: {:7.3f}%, energy error: {:f}, tmp_error: {:f}, relative energy error: {:f}' .format(i, len(self.E_vh), offset[-1], to_be_updated * full_percentage, energy_error, tmp_energy_error, energy_error / energy_norm)) rel_energy_errorT.append(energy_error / energy_norm) energy_errorT.append(energy_error) tmp_errorT.append(tmp_energy_error) return to_be_updatedT, energy_errorT, tmp_errorT, rel_energy_errorT, TOLt, uFineFull_trans_LOD
def StartAlgorithm(self): assert (self.init) # only start the algorithm once # in case not every element is affected, the percentage would be missleading. eps_size = np.size(self.E_vh) self.E_vh = { i: self.E_vh[i] for i in range(np.size(self.E_vh)) if self.E_vh[i] > 0 } list = [v for v in self.E_vh.values()] list.append(0) tols = np.sort(list)[::-1] eps_size_f = np.size(self.E_vh) self.E_f = { i: self.E_f[i] for i in range(np.size(self.E_f)) if self.E_f[i] > 0 } list_f = [v for v in self.E_f.values()] list_f.append(0) tols_f = np.sort(list)[::-1] # make sure we only update one element all the time for i in range(1, np.size(tols)): if tols[i] == tols[i - 1]: tols[i] -= 1e-7 for i in range(1, np.size(tols_f)): if tols_f[i] == tols_f[i - 1]: tols_f[i] -= 1e-7 full_percentage = len(self.E_vh) / eps_size full_percentage_f = len(self.E_f) / eps_size_f world = self.world print('starting algorithm ...... ') TOLt = [] to_be_updatedT = [] energy_errorT = [] rel_energy_errorT = [] tmp_errorT = [] offset = [] TOL = 100 # not relevant for i in range(np.size(tols)): if TOL == 0: pass else: TOL = tols[i] TOLt.append(TOL) offset = self.UpdateNextElement(TOL, offset, Printing=False) if self.init: to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated) pass else: to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated * full_percentage) KFull = pglod.assembleMsStiffnessMatrix(world, self.patchT, self.KmsijT) RFull = pglod.assemblePatchFunction(world, self.patchT, self.RmsijT) Rf = pglod.assemblePatchFunction(world, self.patchT, self.correctorsRhsT) basis = fem.assembleProlongationMatrix(world.NWorldCoarse, world.NCoarseElement) bFull = basis.T * self.MFull * self.f_trans - RFull basisCorrectors = pglod.assembleBasisCorrectors( world, self.patchT, self.correctorsListT) modifiedBasis = basis - basisCorrectors uFull, _ = pglod.solve(world, KFull, bFull, self.boundaryConditions) uLodFine = modifiedBasis * uFull uLodFine += Rf uFineFull_trans_LOD = uLodFine if self.init: self.init = 0 uFineFull_trans_LOD_old = uLodFine energy_norm = np.sqrt( np.dot(uFineFull_trans_LOD, self.AFine_trans * uFineFull_trans_LOD)) # tmp_error tmp_energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - uFineFull_trans_LOD_old), self.AFine_trans * (uFineFull_trans_LOD - uFineFull_trans_LOD_old))) # actual error if self.compare_with_best_LOD: energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - self.u_best_LOD), self.AFine_trans * (uFineFull_trans_LOD - self.u_best_LOD))) else: energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - self.uFineFull_trans), self.AFine_trans * (uFineFull_trans_LOD - self.uFineFull_trans))) uFineFull_trans_LOD_old = uFineFull_trans_LOD print( ' step({:3d}/{}) TOL: {:f}, updates: {:7.3f}%, energy error: {:f}, tmp_error: {:f}, relative energy error: {:f}' .format(i, np.size(tols), TOL, to_be_updated * full_percentage, energy_error, tmp_energy_error, energy_error / energy_norm)) rel_energy_errorT.append(energy_error / energy_norm) energy_errorT.append(energy_error) tmp_errorT.append(tmp_energy_error) if TOL == 0: # stop now break return to_be_updatedT, energy_errorT, tmp_errorT, rel_energy_errorT, TOLt, uFineFull_trans_LOD
def StartAlgorithm(self): assert (self.init) # only start the algorithm once # in case not every element is affected, the percentage would be missleading. eps_size = np.size(self.E_vh) self.E_vh = { i: self.E_vh[i] for i in range(np.size(self.E_vh)) if self.E_vh[i] > 0 } full_percentage = len(self.E_vh) / eps_size world = self.world print('starting algorithm ...... ') TOL = self.StartingTolerance TOLt = [] to_be_updatedT = [] energy_errorT = [] rel_energy_errorT = [] tmp_errorT = [] offset = [] continue_computing = 1 while continue_computing: TOLt.append(TOL) offset, computed = self.UpdateElements(TOL, offset, Printing=False) if computed: pass else: if self.init: pass else: to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated * full_percentage) energy_errorT.append(energy_error) tmp_errorT.append(old_tmp_energy_error) if np.size(offset) / len(self.E_vh) == 1: print(' every corrector has been updated') continue_computing = 0 continue else: print(' skipping TOL {}'.format(TOL)) TOL *= 3 / 4. continue to_be_updated = np.size(offset) / len(self.E_vh) * 100 to_be_updatedT.append(to_be_updated * full_percentage) KFull = pglod.assembleMsStiffnessMatrix(world, self.patchT, self.KmsijT) RFull = pglod.assemblePatchFunction(world, self.patchT, self.RmsijT) Rf = pglod.assemblePatchFunction(world, self.patchT, self.correctorsRhsT) basis = fem.assembleProlongationMatrix(world.NWorldCoarse, world.NCoarseElement) bFull = basis.T * self.MFull * self.f_trans - RFull basisCorrectors = pglod.assembleBasisCorrectors( world, self.patchT, self.correctorsListT) modifiedBasis = basis - basisCorrectors uFull, _ = pglod.solve(world, KFull, bFull, self.boundaryConditions) uLodFine = modifiedBasis * uFull uLodFine += Rf uFineFull_trans_LOD = uLodFine if self.init: uFineFull_trans_LOD_old = uLodFine self.init = 0 energy_norm = np.sqrt( np.dot(uFineFull_trans_LOD, self.AFine_trans * uFineFull_trans_LOD)) # tmp_error tmp_energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - uFineFull_trans_LOD_old), self.AFine_trans * (uFineFull_trans_LOD - uFineFull_trans_LOD_old))) old_tmp_energy_error = tmp_energy_error # actual error energy_error = np.sqrt( np.dot((uFineFull_trans_LOD - self.uFineFull_trans), self.AFine_trans * (uFineFull_trans_LOD - self.uFineFull_trans))) uFineFull_trans_LOD_old = uFineFull_trans_LOD print( ' TOL: {:f}, updates: {:7.3f}%, energy error: {:f}, tmp_error: {:f}, relative energy error: {:f}' .format(TOL, to_be_updated * full_percentage, energy_error, tmp_energy_error, energy_error / energy_norm)) rel_energy_errorT.append(energy_error / energy_norm) energy_errorT.append(energy_error) tmp_errorT.append(tmp_energy_error) if tmp_energy_error > 1e-5: TOL *= 3 / 4. else: if int(np.size(offset) / len(self.E_vh)) == 1: if computed: print(' stop computing') continue_computing = 0 return to_be_updatedT, energy_errorT, tmp_errorT, rel_energy_errorT, TOLt, uFineFull_trans_LOD
def helmholtz_nonlinear_adaptive(mapper, fineLvl, maxCoarseLvl, maxit): NFine = np.array([2**fineLvl, 2**fineLvl]) NpFine = np.prod(NFine + 1) NList = 2**np.arange(1, maxCoarseLvl + 1) ell = 2 # localization parameter k = 30. # wavenumber maxit_Fine = 250 tol = 0.5 # coupled to maximal error indicator xt = util.tCoordinates(NFine) xp = util.pCoordinates(NFine) # multiscale coefficients on the scale NFine-2 np.random.seed(123) sizeK = np.size(xt[:, 0]) nFine = NFine[0] # determine domain D_eps = supp(1-n) = supp(1-A) (all equal for this experiment) indicesIn = (xt[:, 0] > 0.25) & (xt[:, 0] < 0.75) & (xt[:, 1] > 0.25) & ( xt[:, 1] < 0.75) indicesInEps = (xt[:, 0] > 0.25) & (xt[:, 0] < 0.75) & ( xt[:, 1] > 0.25) & (xt[:, 1] < 0.75) # coefficients cA = .2 # lower bound on A CA = 1. # upper bound on A aEps = np.random.uniform(0, 1, sizeK // 16) aEpsPro = np.zeros(sizeK) for i in range((nFine) // 4): aEpsPro[4 * i * (nFine):4 * (i + 1) * (nFine)] = np.tile( np.repeat(aEps[i * (nFine) // 4:(i + 1) * (nFine) // 4], 4), 4) aFine = np.ones(xt.shape[0]) aFine[indicesIn] = (CA - cA) * aEpsPro[indicesIn] + cA cn = 1. # lower bound on n Cn = 1. # upper bound on n nEps = np.random.uniform(0, 1, sizeK // 16) nEpsPro = np.zeros(sizeK) for i in range((nFine) // 4): nEpsPro[4 * i * (nFine):4 * (i + 1) * (nFine)] = np.tile( np.repeat(nEps[i * (nFine) // 4:(i + 1) * (nFine) // 4], 4), 4) k2Fine = k**2 * np.ones(xt.shape[0]) k2Fine[indicesIn] = k**2 * ((Cn - cn) * nEpsPro[indicesIn] + cn) kFine = k * np.ones(xt.shape[0]) Ceps = .85 # upper bound on eps (lower bound is 0) lvl = 4 epsEps = np.random.randint(2, size=(sizeK // lvl**2)) epsEpsPro = np.zeros(sizeK) for i in range((nFine) // lvl): epsEpsPro[lvl * i * (nFine):lvl * (i + 1) * (nFine)] = np.tile( np.repeat(epsEps[i * (nFine) // lvl:(i + 1) * (nFine) // lvl], lvl), lvl) epsFine = np.zeros(xt.shape[0]) epsFine[indicesInEps] = Ceps * epsEpsPro[indicesInEps] # 0 OR Ceps drawCoefficient(NFine, epsFine) xC = xp[:, 0] yC = xp[:, 1] fact = 100. mult = .8 a = .5 b = .25 k2 = 30. # define right-hand side and boundary condition def funcF(x, y): res = mult * (-np.exp(-1.j * k2 * (a * x - b)) * (2 * a**2 * fact**2 * np.sinh(fact * (a * x - b))**2 / (np.cosh(fact * (a * x - b)) + 1)**3 - a**2 * fact**2 * np.cosh(fact * (a * x - b)) / (np.cosh(fact * (a * x - b)) + 1)**2) + a**2 * k2**2 * np.exp(-1.j * k2 * (a * x - b)) / (np.cosh(fact * (a * x - b)) + 1) - 2.j * a**2 * fact * k2 * np.exp(-1.j * k2 * (a * x - b)) * np.sinh(fact * (a * x - b)) / (np.cosh(fact * (a * x - b)) + 1)**2 - k**2 * np.exp(-1.j * k2 * (a * x - b)) / (np.cosh(fact * (a * x - b)) + 1)) return res f = funcF(xC, yC) g = np.zeros(NpFine, dtype='complex128') # bottom boundary g[0:(NFine[0] + 1)] = mult * 1.j * k * 1. / (np.cosh(fact * (a * xC[0:(NFine[0] + 1)] - b)) + 1) * np.exp( -1.j * k2 * (a * xC[0:(NFine[0] + 1)] - b)) # top boundary g[(NpFine - NFine[0] - 1):] = mult * 1.j * k * 1. / (np.cosh(fact * (a * xC[ (NpFine - NFine[0] - 1):NpFine] - b)) + 1) * np.exp( -1.j * k2 * (a * xC[(NpFine - NFine[0] - 1):NpFine] - b)) # left boundary g[0:(NpFine - NFine[0]):( NFine[0] + 1)] = mult * 1.j * k * np.ones_like(yC[0:(NpFine - NFine[0]):( NFine[0] + 1)]) / (np.cosh(fact * (a * 0 - b)) + 1) * np.exp( -1.j * k2 * (a * 0 - b)) + mult * np.ones_like( yC[0:(NpFine - NFine[0]):(NFine[0] + 1)]) * ( a * 1.j * k2 * np.exp(-1.j * k2 * (a * 0 - b)) / (np.cosh((a * 0 - b) * fact) + 1) + a * fact * np.sinh( (a * 0 - b) * fact) * np.exp(-1.j * k2 * (a * 0 - b)) / (np.cosh((a * 0 - b) * fact) + 1)**2) # right boundary g[NFine[0]:NpFine:( NFine[0] + 1)] = mult * 1.j * k * np.ones_like(yC[NFine[0]:NpFine:( NFine[0] + 1)]) / (np.cosh(fact * (a * 1. - b)) + 1) * np.exp( -1.j * k2 * (a * 1. - b)) - mult * np.ones_like( yC[NFine[0]:NpFine:(NFine[0] + 1)]) * ( a * 1.j * k2 * np.exp(-1.j * k2 * (a * 1. - b)) / (np.cosh( (a * 1. - b) * fact) + 1) + a * fact * np.sinh( (a * 1. - b) * fact) * np.exp(-1.j * k2 * (a * 1. - b)) / (np.cosh((a * 1. - b) * fact) + 1)**2) # reference solution uSol = np.zeros(NpFine, dtype='complex128') # boundary conditions boundaryConditions = np.array([[1, 1], [1, 1]]) # Robin boundary worldFine = World(NFine, np.array([1, 1]), boundaryConditions) # fine matrices BdFineFEM = fem.assemblePatchBoundaryMatrix( NFine, fem.localBoundaryMassMatrixGetter(NFine)) MFineFEM = fem.assemblePatchMatrix(NFine, fem.localMassMatrix(NFine)) KFineFEM = fem.assemblePatchMatrix(NFine, fem.localStiffnessMatrix(NFine)) kBdFine = fem.assemblePatchBoundaryMatrix( NFine, fem.localBoundaryMassMatrixGetter(NFine), kFine) KFine = fem.assemblePatchMatrix(NFine, fem.localStiffnessMatrix(NFine), aFine) # incident beam uInc = mult / (np.cosh(fact * (a * xC - b)) + 1) * np.exp(-1.j * k2 * (a * xC - b)) print('***computing reference solution***') uOldFine = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit_Fine): print('-- itFine = %d' % it) knonlinUpreFine = np.abs(uOldFine) knonlinUFine = func.evaluateCQ1(NFine, knonlinUpreFine, xt) k2FineUfine = np.copy(k2Fine) k2FineUfine[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinUFine[indicesInEps]**2 ) # full coefficient, including nonlinearity k2MFine = fem.assemblePatchMatrix( NFine, fem.localMassMatrix(NFine), k2FineUfine) # weighted mass matrix, updated in every iteration nodesFine = np.arange(worldFine.NpFine) fixFine = util.boundarypIndexMap(NFine, boundaryConditions == 0) freeFine = np.setdiff1d(nodesFine, fixFine) # right-hand side (including boundary condition) fhQuad = MFineFEM * f + BdFineFEM * g # fine system lhsh = KFine[freeFine][:, freeFine] - k2MFine[ freeFine][:, freeFine] + 1j * kBdFine[freeFine][:, freeFine] rhsh = fhQuad[freeFine] xFreeFine = sparse.linalg.spsolve(lhsh, rhsh) xFullFine = np.zeros(worldFine.NpFine, dtype='complex128') xFullFine[freeFine] = xFreeFine uOldFine = np.copy(xFullFine) # residual - used as stopping criterion knonlinU = np.abs(uOldFine) knonlinUFineIt = func.evaluateCQ1(NFine, knonlinU, xt) k2FineUfineIt = np.copy(k2Fine) k2FineUfineIt[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinUFineIt[indicesInEps]**2 ) # update full coefficient, including nonlinearity k2MFineIt = fem.assemblePatchMatrix(NFine, fem.localMassMatrix(NFine), k2FineUfineIt) Ares = KFine - k2MFineIt + 1j * kBdFine residual = np.linalg.norm(Ares * xFullFine - fhQuad) / np.linalg.norm( Ares * xFullFine) print('---- residual = %.4e' % residual) if residual < 1e-12: break # stopping criterion uSol = xFullFine # final fine reference solution print('***reference solution computed***\n') ###################################################################################### print('***computing multiscale approximations***') relErrEnergy = np.zeros([len(NList), maxit]) counter = 0 for N in NList: counter += 1 print('H = %.4e' % (1. / N)) NWorldCoarse = np.array([N, N]) NCoarseElement = NFine // NWorldCoarse world = World(NWorldCoarse, NCoarseElement, boundaryConditions) NpCoarse = np.prod(NWorldCoarse + 1) uOldUps = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit): print('-- it = %d:' % it) knonlinUpre = np.abs(uOldUps) knonlinU = func.evaluateCQ1(NFine, knonlinUpre, xt) k2FineU = np.copy(k2Fine) k2FineU[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinU[indicesInEps]**2) print('---- starting computation of correctors') def computeLocalContribution(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def computeIndicators(TInd): k2FineUPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineU) k2FineUOldPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineUOld) E_vh = lod.computeErrorIndicatorCoarse_helmholtz( patchT[TInd], muTPrime[TInd], k2FineUOldPatch, k2FineUPatch) return E_vh def UpdateCorrectors(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def UpdateElements(tol, E, Kmsij_old, Mmsij_old, Bdmsij_old, correctors_old, mu_old): print('---- apply tolerance') Elements_to_be_updated = [] for (i, eps) in E.items(): if eps > tol: Elements_to_be_updated.append(i) if len(E) > 0: print( '---- total percentage of element correctors to be updated: %.4f' % (100 * np.size(Elements_to_be_updated) / len(mu_old)), flush=True) print('---- update local contributions') KmsijT_list = list(np.copy(Kmsij_old)) MmsijT_list = list(np.copy(Mmsij_old)) BdmsijT_list = list(np.copy(Bdmsij_old)) muT_list = np.copy(mu_old) for T in np.setdiff1d(range(world.NtCoarse), Elements_to_be_updated): patch = Patch(world, ell, T) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctors_old[T], aPatch, kPatch, k2Patch) KmsijT_list[T] = csi.Kmsij MmsijT_list[T] = csi.Mmsij BdmsijT_list[T] = csi.Bdmsij muT_list[T] = csi.muTPrime if np.size(Elements_to_be_updated) != 0: #print('---- update correctors') patchT_irrelevant, correctorsListTNew, KmsijTNew, MmsijTNew, BdmsijTNew, muTPrimeNew = zip( *mapper(UpdateCorrectors, Elements_to_be_updated)) #print('---- update correctorsList') correctorsListT_list = list(np.copy(correctors_old)) i = 0 for T in Elements_to_be_updated: KmsijT_list[T] = KmsijTNew[i] correctorsListT_list[T] = correctorsListTNew[i] MmsijT_list[T] = MmsijTNew[i] BdmsijT_list[T] = BdmsijTNew[i] muT_list[T] = muTPrimeNew[i] i += 1 KmsijT = tuple(KmsijT_list) correctorsListT = tuple(correctorsListT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime else: KmsijT = tuple(KmsijT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctors_old, KmsijT, MmsijT, BdmsijT, muTPrime if it == 0: patchT, correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = zip( *mapper(computeLocalContribution, range(world.NtCoarse))) else: E_vh = list(mapper(computeIndicators, range(world.NtCoarse))) print( '---- maximal value error estimator for basis correctors {}' .format(np.max(E_vh))) E = {i: E_vh[i] for i in range(np.size(E_vh)) if E_vh[i] > 0} # loop over elements with possible recomputation of correctors correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = UpdateElements( tol * np.max(E_vh), E, KmsijT, MmsijT, BdmsijT, correctorsListT, muTPrime) # tol scaled by maximal error indicator print('---- finished computation of correctors') KLOD = pglod.assembleMsStiffnessMatrix( world, patchT, KmsijT) # ms stiffness matrix k2MLOD = pglod.assembleMsStiffnessMatrix(world, patchT, MmsijT) # ms mass matrix kBdLOD = pglod.assembleMsStiffnessMatrix( world, patchT, BdmsijT) # ms boundary matrix MFEM = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) BdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse)) print('---- coarse matrices assembled') nodes = np.arange(world.NpCoarse) fix = util.boundarypIndexMap(NWorldCoarse, boundaryConditions == 0) free = np.setdiff1d(nodes, fix) assert (nodes.all() == free.all()) # compute global interpolation matrix patchGlobal = Patch(world, NFine[0] + 2, 0) IH = interp.L2ProjectionPatchMatrix(patchGlobal, boundaryConditions) assert (IH.shape[0] == NpCoarse) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) fHQuad = basis.T * MFineFEM * f + basis.T * BdFineFEM * g print('---- solving coarse system') # coarse system lhsH = KLOD[free][:, free] - k2MLOD[ free][:, free] + 1j * kBdLOD[free][:, free] rhsH = fHQuad[free] xFree = sparse.linalg.spsolve(lhsH, rhsH) basisCorrectors = pglod.assembleBasisCorrectors( world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors xFull = np.zeros(world.NpCoarse, dtype='complex128') xFull[free] = xFree uLodCoarse = basis * xFull uLodFine = modifiedBasis * xFull uOldUps = np.copy(uLodFine) k2FineUOld = np.copy(k2FineU) # visualization if it == maxit - 1 and N == 2**4: grid = uLodFine.reshape(NFine + 1, order='C') plt.figure(2) plt.title('LOD_ad, Hlvl=4 - Ex 2') plt.imshow(grid.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() grid2 = uSol.reshape(NFine + 1, order='C') plt.figure(1) plt.title('reference solution - Ex 2') plt.imshow(grid2.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() grid3 = uInc.reshape(NFine + 1, order='C') plt.figure(6) plt.title('incident beam - Ex 2') plt.imshow(grid3.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() Err = np.sqrt( np.dot((uSol - uLodFine).conj(), KFineFEM * (uSol - uLodFine)) + k**2 * np.dot((uSol - uLodFine).conj(), MFineFEM * (uSol - uLodFine))) ErrEnergy = Err / np.sqrt( np.dot((uSol).conj(), KFineFEM * (uSol)) + k**2 * np.dot((uSol).conj(), MFineFEM * (uSol))) print('---- ', np.abs(ErrEnergy), '\n***********************************************') # save errors in arrays relErrEnergy[counter - 1, it] = ErrEnergy print('\n') ###################################################################################### print( '***computing multiscale approximations without updates of correctors***' ) relErrEnergyNoUpdate = np.zeros([len(NList), maxit]) counter = 0 for N in NList: counter += 1 print('H = %.4e' % (1. / N)) NWorldCoarse = np.array([N, N]) NCoarseElement = NFine // NWorldCoarse world = World(NWorldCoarse, NCoarseElement, boundaryConditions) NpCoarse = np.prod(NWorldCoarse + 1) uOldUps = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit): print('-- it = %d:' % it) knonlinUpre = np.abs(uOldUps) knonlinU = func.evaluateCQ1(NFine, knonlinUpre, xt) k2FineU = np.copy(k2Fine) k2FineU[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinU[indicesInEps]**2) print('---- starting computation of correctors') def computeLocalContribution(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def computeIndicators(TInd): k2FineUPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineU) k2FineUOldPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineUOld) E_vh = lod.computeErrorIndicatorCoarse_helmholtz( patchT[TInd], muTPrime[TInd], k2FineUOldPatch, k2FineUPatch) return E_vh def UpdateCorrectors(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def UpdateElements(tol, E, Kmsij_old, Mmsij_old, Bdmsij_old, correctors_old, mu_old): print('---- apply tolerance') Elements_to_be_updated = [] for (i, eps) in E.items(): if eps > tol: Elements_to_be_updated.append(i) if len(E) > 0: print( '---- total percentage of element correctors to be updated: %.4f' % (100 * np.size(Elements_to_be_updated) / len(mu_old)), flush=True) print('---- update local contributions') KmsijT_list = list(np.copy(Kmsij_old)) MmsijT_list = list(np.copy(Mmsij_old)) BdmsijT_list = list(np.copy(Bdmsij_old)) muT_list = np.copy(mu_old) for T in np.setdiff1d(range(world.NtCoarse), Elements_to_be_updated): patch = Patch(world, ell, T) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctors_old[T], aPatch, kPatch, k2Patch) KmsijT_list[T] = csi.Kmsij MmsijT_list[T] = csi.Mmsij BdmsijT_list[T] = csi.Bdmsij muT_list[T] = csi.muTPrime if np.size(Elements_to_be_updated) != 0: #print('---- update correctors') patchT_irrelevant, correctorsListTNew, KmsijTNew, MmsijTNew, BdmsijTNew, muTPrimeNew = zip( *mapper(UpdateCorrectors, Elements_to_be_updated)) #print('---- update correctorsList') correctorsListT_list = list(np.copy(correctors_old)) i = 0 for T in Elements_to_be_updated: KmsijT_list[T] = KmsijTNew[i] correctorsListT_list[T] = correctorsListTNew[i] MmsijT_list[T] = MmsijTNew[i] BdmsijT_list[T] = BdmsijTNew[i] muT_list[T] = muTPrimeNew[i] i += 1 KmsijT = tuple(KmsijT_list) correctorsListT = tuple(correctorsListT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime else: KmsijT = tuple(KmsijT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctors_old, KmsijT, MmsijT, BdmsijT, muTPrime if it == 0: patchT, correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = zip( *mapper(computeLocalContribution, range(world.NtCoarse))) else: E_vh = list(mapper(computeIndicators, range(world.NtCoarse))) print( '---- maximal value error estimator for basis correctors {}' .format(np.max(E_vh))) E = {i: E_vh[i] for i in range(np.size(E_vh)) if E_vh[i] > 0} # loop over elements with possible recomputation of correctors correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = UpdateElements( 2. * np.max(E_vh), E, KmsijT, MmsijT, BdmsijT, correctorsListT, muTPrime) # no updates print('---- finished computation of correctors') KLOD = pglod.assembleMsStiffnessMatrix( world, patchT, KmsijT) # ms stiffness matrix k2MLOD = pglod.assembleMsStiffnessMatrix(world, patchT, MmsijT) # ms mass matrix kBdLOD = pglod.assembleMsStiffnessMatrix( world, patchT, BdmsijT) # ms boundary matrix MFEM = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) BdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse)) print('---- coarse matrices assembled') nodes = np.arange(world.NpCoarse) fix = util.boundarypIndexMap(NWorldCoarse, boundaryConditions == 0) free = np.setdiff1d(nodes, fix) assert (nodes.all() == free.all()) # compute global interpolation matrix patchGlobal = Patch(world, NFine[0] + 2, 0) IH = interp.L2ProjectionPatchMatrix(patchGlobal, boundaryConditions) assert (IH.shape[0] == NpCoarse) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) fHQuad = basis.T * MFineFEM * f + basis.T * BdFineFEM * g print('---- solving coarse system') # coarse system lhsH = KLOD[free][:, free] - k2MLOD[ free][:, free] + 1j * kBdLOD[free][:, free] rhsH = fHQuad[free] xFree = sparse.linalg.spsolve(lhsH, rhsH) basisCorrectors = pglod.assembleBasisCorrectors( world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors xFull = np.zeros(world.NpCoarse, dtype='complex128') xFull[free] = xFree uLodCoarse = basis * xFull uLodFine = modifiedBasis * xFull uOldUps = np.copy(uLodFine) k2FineUOld = np.copy(k2FineU) # visualization if it == maxit - 1 and N == 2**4: grid = uLodFine.reshape(NFine + 1, order='C') plt.figure(3) plt.title('LOD_inf, Hlvl=4 - Ex 2') plt.imshow(grid.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() Err = np.sqrt( np.dot((uSol - uLodFine).conj(), KFineFEM * (uSol - uLodFine)) + k**2 * np.dot((uSol - uLodFine).conj(), MFineFEM * (uSol - uLodFine))) ErrEnergy = Err / np.sqrt( np.dot((uSol).conj(), KFineFEM * (uSol)) + k**2 * np.dot((uSol).conj(), MFineFEM * (uSol))) print('---- ', np.abs(ErrEnergy), '\n***********************************************') # save errors in arrays relErrEnergyNoUpdate[counter - 1, it] = ErrEnergy print('\n') ###################################################################################### print( '***computing multiscale approximations where all correctors in the part of the domain with active nonlinearity are recomputed***' ) relErrEnergyFullUpdate = np.zeros([len(NList), maxit]) counter = 0 for N in NList: counter += 1 print('H = %.4e' % (1. / N)) NWorldCoarse = np.array([N, N]) NCoarseElement = NFine // NWorldCoarse world = World(NWorldCoarse, NCoarseElement, boundaryConditions) NpCoarse = np.prod(NWorldCoarse + 1) uOldUps = np.zeros(NpFine, dtype='complex128') for it in np.arange(maxit): print('-- it = %d:' % it) knonlinUpre = np.abs(uOldUps) knonlinU = func.evaluateCQ1(NFine, knonlinUpre, xt) k2FineU = np.copy(k2Fine) k2FineU[indicesInEps] *= ( 1. + epsFine[indicesInEps] * knonlinU[indicesInEps]**2) print('---- starting computation of correctors') def computeLocalContribution(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def computeIndicators(TInd): k2FineUPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineU) k2FineUOldPatch = lambda: coef.localizeCoefficient( patchT[TInd], k2FineUOld) E_vh = lod.computeErrorIndicatorCoarse_helmholtz( patchT[TInd], muTPrime[TInd], k2FineUOldPatch, k2FineUPatch) return E_vh def UpdateCorrectors(TInd): patch = Patch(world, ell, TInd) IPatch = lambda: interp.L2ProjectionPatchMatrix( patch, boundaryConditions) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) correctorsList = lod.computeBasisCorrectors_helmholtz( patch, IPatch, aPatch, kPatch, k2Patch) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctorsList, aPatch, kPatch, k2Patch) # adapted for Helmholtz setting return patch, correctorsList, csi.Kmsij, csi.Mmsij, csi.Bdmsij, csi.muTPrime def UpdateElements(tol, E, Kmsij_old, Mmsij_old, Bdmsij_old, correctors_old, mu_old): print('---- apply tolerance') Elements_to_be_updated = [] for (i, eps) in E.items(): if eps > tol: Elements_to_be_updated.append(i) if len(E) > 0: print( '---- total percentage of element correctors to be updated: %.4f' % (100 * np.size(Elements_to_be_updated) / len(mu_old)), flush=True) print('---- update local contributions') KmsijT_list = list(np.copy(Kmsij_old)) MmsijT_list = list(np.copy(Mmsij_old)) BdmsijT_list = list(np.copy(Bdmsij_old)) muT_list = np.copy(mu_old) for T in np.setdiff1d(range(world.NtCoarse), Elements_to_be_updated): patch = Patch(world, ell, T) aPatch = lambda: coef.localizeCoefficient(patch, aFine) kPatch = lambda: coef.localizeCoefficient(patch, kFine) k2Patch = lambda: coef.localizeCoefficient(patch, k2FineU) csi = lod.computeBasisCoarseQuantities_helmholtz( patch, correctors_old[T], aPatch, kPatch, k2Patch) KmsijT_list[T] = csi.Kmsij MmsijT_list[T] = csi.Mmsij BdmsijT_list[T] = csi.Bdmsij muT_list[T] = csi.muTPrime if np.size(Elements_to_be_updated) != 0: #print('---- update correctors') patchT_irrelevant, correctorsListTNew, KmsijTNew, MmsijTNew, BdmsijTNew, muTPrimeNew = zip( *mapper(UpdateCorrectors, Elements_to_be_updated)) #print('---- update correctorsList') correctorsListT_list = list(np.copy(correctors_old)) i = 0 for T in Elements_to_be_updated: KmsijT_list[T] = KmsijTNew[i] correctorsListT_list[T] = correctorsListTNew[i] MmsijT_list[T] = MmsijTNew[i] BdmsijT_list[T] = BdmsijTNew[i] muT_list[T] = muTPrimeNew[i] i += 1 KmsijT = tuple(KmsijT_list) correctorsListT = tuple(correctorsListT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime else: KmsijT = tuple(KmsijT_list) MmsijT = tuple(MmsijT_list) BdmsijT = tuple(BdmsijT_list) muTPrime = tuple(muT_list) return correctors_old, KmsijT, MmsijT, BdmsijT, muTPrime if it == 0: patchT, correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = zip( *mapper(computeLocalContribution, range(world.NtCoarse))) else: E_vh = list(mapper(computeIndicators, range(world.NtCoarse))) print( '---- maximal value error estimator for basis correctors {}' .format(np.max(E_vh))) E = {i: E_vh[i] for i in range(np.size(E_vh)) if E_vh[i] > 0} # loop over elements with possible recomputation of correctors correctorsListT, KmsijT, MmsijT, BdmsijT, muTPrime = UpdateElements( 0., E, KmsijT, MmsijT, BdmsijT, correctorsListT, muTPrime) # no updates print('---- finished computation of correctors') KLOD = pglod.assembleMsStiffnessMatrix( world, patchT, KmsijT) # ms stiffness matrix k2MLOD = pglod.assembleMsStiffnessMatrix(world, patchT, MmsijT) # ms mass matrix kBdLOD = pglod.assembleMsStiffnessMatrix( world, patchT, BdmsijT) # ms boundary matrix MFEM = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) BdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse)) print('---- coarse matrices assembled') nodes = np.arange(world.NpCoarse) fix = util.boundarypIndexMap(NWorldCoarse, boundaryConditions == 0) free = np.setdiff1d(nodes, fix) assert (nodes.all() == free.all()) # compute global interpolation matrix patchGlobal = Patch(world, NFine[0] + 2, 0) IH = interp.L2ProjectionPatchMatrix(patchGlobal, boundaryConditions) assert (IH.shape[0] == NpCoarse) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) fHQuad = basis.T * MFineFEM * f + basis.T * BdFineFEM * g print('---- solving coarse system') # coarse system lhsH = KLOD[free][:, free] - k2MLOD[ free][:, free] + 1j * kBdLOD[free][:, free] rhsH = fHQuad[free] xFree = sparse.linalg.spsolve(lhsH, rhsH) basisCorrectors = pglod.assembleBasisCorrectors( world, patchT, correctorsListT) modifiedBasis = basis - basisCorrectors xFull = np.zeros(world.NpCoarse, dtype='complex128') xFull[free] = xFree uLodCoarse = basis * xFull uLodFine = modifiedBasis * xFull uOldUps = np.copy(uLodFine) k2FineUOld = np.copy(k2FineU) # visualization if it == maxit - 1 and N == 2**4: grid = uLodFine.reshape(NFine + 1, order='C') plt.figure(7) plt.title('LOD_inf, Hlvl=4 - Ex 2') plt.imshow(grid.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() Err = np.sqrt( np.dot((uSol - uLodFine).conj(), KFineFEM * (uSol - uLodFine)) + k**2 * np.dot((uSol - uLodFine).conj(), MFineFEM * (uSol - uLodFine))) ErrEnergy = Err / np.sqrt( np.dot((uSol).conj(), KFineFEM * (uSol)) + k**2 * np.dot((uSol).conj(), MFineFEM * (uSol))) print('---- ', np.abs(ErrEnergy), '\n***********************************************') # save errors in arrays relErrEnergyFullUpdate[counter - 1, it] = ErrEnergy print('\n') ###################################################################################### print('***computing FEM approximations***') FEMrelErrEnergy = np.zeros([len(NList), maxit]) counter = 0 for N in NList: counter += 1 print('H = %.4e' % (1. / N)) NWorldCoarse = np.array([N, N]) NCoarseElement = NFine // NWorldCoarse world = World(NWorldCoarse, NCoarseElement, boundaryConditions) NpCoarse = np.prod(NWorldCoarse + 1) xT = util.tCoordinates(NWorldCoarse) xP = util.pCoordinates(NWorldCoarse) uOld = np.zeros(NpCoarse, dtype='complex128') # compute coarse coefficients by averaging NtC = np.prod(NWorldCoarse) aCoarse = np.zeros(NtC) kCoarse = k * np.ones(xT.shape[0]) k2Coarse = np.zeros(NtC) epsCoarse = np.zeros(NtC) for Q in range(NtC): patch = Patch(world, 0, Q) aPatch = coef.localizeCoefficient(patch, aFine) epsPatch = coef.localizeCoefficient(patch, epsFine) k2Patch = coef.localizeCoefficient(patch, k2Fine) aCoarse[Q] = np.sum(aPatch) / (len(aPatch)) k2Coarse[Q] = np.sum(k2Patch) / (len(k2Patch)) epsCoarse[Q] = np.sum(epsPatch) / (len(epsPatch)) # coarse matrices KFEM = fem.assemblePatchMatrix(NWorldCoarse, fem.localStiffnessMatrix(NWorldCoarse), aCoarse) kBdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse), kCoarse) MFEM = fem.assemblePatchMatrix(NWorldCoarse, world.MLocCoarse) BdFEM = fem.assemblePatchBoundaryMatrix( NWorldCoarse, fem.localBoundaryMassMatrixGetter(NWorldCoarse)) for it in np.arange(maxit): print('-- it = %d:' % it) knonlinUpre = np.abs(uOld) knonlinU = func.evaluateCQ1(NWorldCoarse, knonlinUpre, xT) k2CoarseU = np.copy(k2Coarse) k2CoarseU *= (1. + epsCoarse * knonlinU**2) # update weighted mass matrix k2MFEM = fem.assemblePatchMatrix(NWorldCoarse, fem.localMassMatrix(NWorldCoarse), k2CoarseU) nodes = np.arange(world.NpCoarse) fix = util.boundarypIndexMap(NWorldCoarse, boundaryConditions == 0) free = np.setdiff1d(nodes, fix) assert (nodes.all() == free.all()) basis = fem.assembleProlongationMatrix(NWorldCoarse, NCoarseElement) fHQuad = basis.T * MFineFEM * f + basis.T * BdFineFEM * g print('---- solving coarse system') # coarse system lhsH = KFEM[free][:, free] - k2MFEM[ free][:, free] + 1j * kBdFEM[free][:, free] rhsH = fHQuad[free] xFree = sparse.linalg.spsolve(lhsH, rhsH) xFull = np.zeros(world.NpCoarse, dtype='complex128') xFull[free] = xFree uCoarseInt = basis * xFull uOld = np.copy(xFull) # visualization if it == maxit - 1 and N == 2**4: grid = uCoarseInt.reshape(NFine + 1, order='C') plt.figure(4) plt.title('FEM, Hlvl=4 - Ex 2') plt.imshow(grid.real, extent=(xC.min(), xC.max(), yC.min(), yC.max()), cmap=plt.cm.hot, origin='lower', vmin=-.6, vmax=.6) plt.colorbar() Err = np.sqrt( np.dot((uSol - uCoarseInt).conj(), KFineFEM * (uSol - uCoarseInt)) + k**2 * np.dot( (uSol - uCoarseInt).conj(), MFineFEM * (uSol - uCoarseInt))) ErrEnergy = Err / np.sqrt( np.dot((uSol).conj(), KFineFEM * (uSol)) + k**2 * np.dot((uSol).conj(), MFineFEM * (uSol))) print('---- ', np.abs(ErrEnergy), '\n***********************************************') # save errors in arrays FEMrelErrEnergy[counter - 1, it] = ErrEnergy print('\n') # error plots errLOD_2 = np.min(relErrEnergy, 1) errLOD0_2 = np.min(relErrEnergyNoUpdate, 1) errLODall_2 = np.min(relErrEnergyFullUpdate, 1) errFEM_2 = np.min(FEMrelErrEnergy, 1) Hs = 0.5**np.arange(1, maxCoarseLvl + 1) plt.figure(5) plt.title('Relative energy errors w.r.t H - Ex 2') plt.plot(Hs, errLOD_2, 'x-', color='blue', label='LOD_ad') plt.plot(Hs, errLOD0_2, 'x-', color='green', label='LOD_inf') plt.plot(Hs, errLODall_2, 'x-', color='orange', label='LOD_0') plt.plot(Hs, errFEM_2, 'x-', color='red', label='FEM') plt.plot([0.5, 0.0078125], [0.75, 0.01171875], color='black', linestyle='dashed', label='order 1') plt.yscale('log') plt.xscale('log') plt.legend() plt.show()