def solve_bvp(self,wave_number,rhs): from scipy.sparse.linalg import gmres from bempp.tools import RealOperator self._residuals[wave_number] = [] def evaluate_residual(res): self._residuals[wave_number].append(res) n = len(rhs[0]) rhs_dual = (self._identity*rhs[0].reshape(n,1)).ravel() op_found_in_cache = False if self._operator_cache: try: op = self._boundary_operator_cache(wave_number) op_found_in_cache = True except: pass if not op_found_in_cache: slp_bnd_op = _bempplib.createMaxwell3dSingleLayerBoundaryOperator(self._context,self._space, self._space,self._space, 1.0j*wave_number).weakForm() slp_bnd_op_real = RealOperator(slp_bnd_op) prec = None if self._use_aca_lu_preconditioner: prec = RealOperator(_bempplib.acaOperatorApproximateLuInverse(slp_bnd_op,self._aca_lu_delta)) if self._operator_cache: self._boundary_operator_cache.insert(wave_number,(slp_bnd_op_real,prec)) rhs_dual_real = _np.hstack([_np.real(rhs_dual),_np.imag(rhs_dual)]) sol_real,info = gmres(slp_bnd_op_real,rhs_dual_real,tol=self._gmres_tol,maxiter=self._gmres_max_iter,M=prec,callback=evaluate_residual) if info != 0: raise Exception('GMRES did not converge for wavenumber '+str(wave_number)+'.') sol = sol_real[:n]+1j*sol_real[n:] return [sol.ravel()]
def solve_bvp(self,wave_number,rhs): self._residuals[wave_number] = [] def evaluate_residual(res): self._residuals[wave_number].append(res) k_ext = 1.0j*wave_number * _np.sqrt(self._eps_ext * self._mu_ext) k_int = 1.0j*wave_number * _np.sqrt(self._eps_int * self._mu_int) rho = (k_int * self._mu_ext) / (k_ext * self._mu_int) op_found_in_cache = False if self._operator_cache: try: op,prec = self._boundary_operator_cache(wave_number) op_found_in_cache = True except: pass if not op_found_in_cache: context = self._context space = self._space slpOpExt = _bempplib.createMaxwell3dSingleLayerBoundaryOperator( context, space, space, space, k_ext, "SLP_ext") dlpOpExt = _bempplib.createMaxwell3dDoubleLayerBoundaryOperator( context, space, space, space, k_ext, "DLP_ext") slpOpInt = _bempplib.createMaxwell3dSingleLayerBoundaryOperator( context, space, space, space, k_int, "SLP_int") dlpOpInt = _bempplib.createMaxwell3dDoubleLayerBoundaryOperator( context, space, space, space, k_int, "DLP_int") idOp = _bempplib.createMaxwell3dIdentityOperator( context, space, space, space, "Id") # Form the left- and right-hand-side operators lhsOp00 = -(slpOpExt + rho * slpOpInt) lhsOp01 = lhsOp10 = dlpOpExt + dlpOpInt lhsOp11 = slpOpExt + (1. / rho) * slpOpInt lhsOp = _bempplib.createBlockedBoundaryOperator( context, [[lhsOp00, lhsOp01], [lhsOp10, lhsOp11]]) precTol = self._aca_lu_delta invLhsOp00 = _bempplib.acaOperatorApproximateLuInverse( lhsOp00.weakForm().asDiscreteAcaBoundaryOperator(), precTol) invLhsOp11 = _bempplib.acaOperatorApproximateLuInverse( lhsOp11.weakForm().asDiscreteAcaBoundaryOperator(), precTol) prec = _bempplib.discreteBlockDiagonalPreconditioner([invLhsOp00, invLhsOp11]) op = lhsOp # Construct the grid functions representing the traces of the incident field incDirichletTrace = _bempplib.createGridFunction( context, space, space, coefficients=rhs[0]) incNeumannTrace = 1./(1j*k_ext)*_bempplib.createGridFunction( context, space, space, coefficients=rhs[1]) self._inc_dirichlet_traces[wave_number] = incDirichletTrace self._inc_neumann_traces[wave_number] = incNeumannTrace # Construct the right-hand-side grid function rhs = [idOp * incNeumannTrace, idOp * incDirichletTrace] solver = _bempplib.createDefaultIterativeSolver(op) solver.initializeSolver(_bempplib.defaultGmresParameterList(self._gmres_tol), prec) # Solve the equation solution = solver.solve(rhs) print solution.solverMessage() # Extract the solution components in the form of grid functions extDirichletTrace = solution.gridFunction(0) extNeumannTrace = solution.gridFunction(1) if self._operator_cache: self._boundary_operator_cache.insert(wave_number,(op,prec)) scatt_dirichlet_ext_fun = extDirichletTrace - self._inc_dirichlet_traces[wave_number] print "Dirichlet Error "+str(scatt_dirichlet_ext_fun.L2Norm()/extDirichletTrace.L2Norm()) scatt_neumann_ext_fun = extNeumannTrace - self._inc_neumann_traces[wave_number] print "Neumann Error "+str(scatt_neumann_ext_fun.L2Norm()/extNeumannTrace.L2Norm()) return [extDirichletTrace.coefficients(),extNeumannTrace.coefficients()]