示例#1
0
    def _solve_(self, L, x, b):
        diag = L.takeDiagonal()
        maxdiag = max(numerix.absolute(diag))

        L = L * (1 / maxdiag)
        b = b * (1 / maxdiag)

        LU = superlu.factorize(L.matrix.to_csr())

        if DEBUG:
            import sys
            print(L.matrix, file=sys.stderr)

        error0 = numerix.sqrt(numerix.sum((L * x - b)**2))

        for iteration in range(self.iterations):
            errorVector = L * x - b

            if (numerix.sqrt(numerix.sum(errorVector**2)) / error0)  <= self.tolerance:
                break

            xError = numerix.zeros(len(b), 'd')
            LU.solve(errorVector, xError)
            x[:] = x - xError

        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT
            PRINT('iterations: %d / %d' % (iteration+1, self.iterations))
            PRINT('residual:', numerix.sqrt(numerix.sum(errorVector**2)))
示例#2
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    def _solve_(self, L, x, b):
        """
        `_solve_` is only for use by solvers which may use
        preconditioning. If you are writing a solver which
        doesn't use preconditioning, this must be overridden.

        :Parameters:
            - `L`: a `fipy.matrices.pysparseMatrix._PysparseMeshMatrix`.
            - `x`: a `numpy.ndarray`.
            - `b`: a `numpy.ndarray`.
        """

        A = L.matrix

        if self.preconditioner is None:
            P = None
        else:
            P, A = self.preconditioner._applyToMatrix(A)

        info, iter, relres = self.solveFnc(A, b, x, self.tolerance,
                                           self.iterations, P)

        self._raiseWarning(info, iter, relres)

        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT
            PRINT('iterations: %d / %d' % (iter, self.iterations))

            if info < 0:
                PRINT('failure', self._warningList[info].__class__.__name__)
            PRINT('relres:', relres)
示例#3
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    def _solve_(self, L, x, b):
        diag = L.takeDiagonal()
        maxdiag = max(numerix.absolute(diag))

        L = L * (1 / maxdiag)
        b = b * (1 / maxdiag)

        LU = splu(L.matrix.asformat("csc"),
                  diag_pivot_thresh=1.,
                  drop_tol=0.,
                  relax=1,
                  panel_size=10,
                  permc_spec=3)

        error0 = numerix.sqrt(numerix.sum((L * x - b)**2))

        for iteration in range(min(self.iterations, 10)):
            errorVector = L * x - b

            if (numerix.sqrt(numerix.sum(errorVector**2)) /
                    error0) <= self.tolerance:
                break

            xError = LU.solve(errorVector)
            x[:] = x - xError

        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT
            PRINT('iterations: %d / %d' % (iteration + 1, self.iterations))
            PRINT('residual:', numerix.sqrt(numerix.sum(errorVector**2)))

        return x
    def _solve_(self, L, x, b):
         
        for iteration in range(self.iterations):
             # errorVector = L*x - b
             errorVector = Epetra.Vector(L.RangeMap())
             L.Multiply(False, x, errorVector)
             # If A is an Epetra.Vector with map M
             # and B is an Epetra.Vector with map M
             # and C = A - B
             # then C is an Epetra.Vector with *no map* !!!?!?!
             errorVector -= b

             tol = errorVector.Norm1()

             if iteration == 0:
                 tol0 = tol
                 
             if (tol / tol0) <= self.tolerance: 
                 break

             xError = Epetra.Vector(L.RowMap())
             
             Problem = Epetra.LinearProblem(L, xError, errorVector)
             Solver = self.Factory.Create("Klu", Problem)
             Solver.Solve()

             x[:] = x - xError
             
        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT        
            PRINT('iterations: %d / %d' % (iteration + 1, self.iterations))
            PRINT('residual:', errorVector.Norm2())
示例#5
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    def _solve_(self, L, x, b):
        ksp = PETSc.KSP()
        ksp.create(PETSc.COMM_WORLD)
        ksp.setType("preonly")
        ksp.getPC().setType(self.preconditioner)
        # TODO: SuperLU invoked with PCFactorSetMatSolverType(pc, MATSOLVERSUPERLU)
        #       see: http://www.mcs.anl.gov/petsc/petsc-dev/src/ksp/ksp/examples/tutorials/ex52.c.html
        # PETSc.PC().setFactorSolverType("superlu")
        
        L.assemblyBegin()
        L.assemblyEnd()
        ksp.setOperators(L)
        ksp.setFromOptions()
        
        for iteration in range(self.iterations):
            errorVector = L * x - b
            tol = errorVector.norm()
            
            if iteration == 0:
                tol0 = tol
                
            if (tol / tol0) <= self.tolerance:
                break
                
            xError = x.copy()

            ksp.solve(errorVector, xError)
            x -= xError
            
        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT
#             L.view()
#             b.view()
            PRINT('solver:', ksp.type)
            PRINT('precon:', ksp.getPC().type)
            PRINT('iterations: %d / %d' % (iteration+1, self.iterations))
            PRINT('residual:', errorVector.norm(1))
示例#6
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    def _solve_(self, L, x, b):

        Solver = AztecOO.AztecOO(L, x, b)
        Solver.SetAztecOption(AztecOO.AZ_solver, self.solver)

        ##        Solver.SetAztecOption(AztecOO.AZ_kspace, 30)

        Solver.SetAztecOption(AztecOO.AZ_output, AztecOO.AZ_none)

        if self.preconditioner is not None:
            self.preconditioner._applyToSolver(solver=Solver, matrix=L)
        else:
            Solver.SetAztecOption(AztecOO.AZ_precond, AztecOO.AZ_none)

        output = Solver.Iterate(self.iterations, self.tolerance)

        if self.preconditioner is not None:
            if hasattr(self.preconditioner, 'Prec'):
                del self.preconditioner.Prec

        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            status = Solver.GetAztecStatus()

            from fipy.tools.debug import PRINT
            PRINT('iterations: %d / %d' %
                  (status[AztecOO.AZ_its], self.iterations))
            failure = {
                AztecOO.AZ_normal: 'AztecOO.AZ_normal',
                AztecOO.AZ_param: 'AztecOO.AZ_param',
                AztecOO.AZ_breakdown: 'AztecOO.AZ_breakdown',
                AztecOO.AZ_loss: 'AztecOO.AZ_loss',
                AztecOO.AZ_ill_cond: 'AztecOO.AZ_ill_cond',
                AztecOO.AZ_maxits: 'AztecOO.AZ_maxits'
            }

            PRINT('failure', failure[status[AztecOO.AZ_why]])

            PRINT('AztecOO.AZ_r:', status[AztecOO.AZ_r])
            PRINT('AztecOO.AZ_scaled_r:', status[AztecOO.AZ_scaled_r])
            PRINT('AztecOO.AZ_rec_r:', status[AztecOO.AZ_rec_r])
            PRINT('AztecOO.AZ_solve_time:', status[AztecOO.AZ_solve_time])
            PRINT('AztecOO.AZ_Aztec_version:',
                  status[AztecOO.AZ_Aztec_version])

        return output
示例#7
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    def _solve_(self, L, x, b):
        ksp = PETSc.KSP()
        ksp.create(L.comm)
        ksp.setType(self.solver)
        if self.preconditioner is not None:
            ksp.getPC().setType(self.preconditioner)
        ksp.setTolerances(rtol=self.tolerance, max_it=self.iterations)
        L.assemble()
        ksp.setOperators(L)
        ksp.setFromOptions()
        ksp.solve(b, x)

        if 'FIPY_VERBOSE_SOLVER' in os.environ:
            from fipy.tools.debug import PRINT
            #             L.view()
            #             b.view()
            PRINT('solver:', ksp.type)
            PRINT('precon:', ksp.getPC().type)
            PRINT('convergence: %s' % _reason[ksp.reason])
            PRINT('iterations: %d / %d' % (ksp.its, self.iterations))
            PRINT('norm:', ksp.norm)
            PRINT('norm_type:', ksp.norm_type)