Exemple #1
0
        private void ExperimentalSolver(out double mintime, out double maxtime, out bool Converged, out int NoOfIter, out int DOFs)
        {
            using (var tr = new FuncTrace()) {
                mintime   = double.MaxValue;
                maxtime   = 0;
                Converged = false;
                NoOfIter  = int.MaxValue;
                DOFs      = 0;

                AggregationGridBasis[][] XAggB;
                using (new BlockTrace("Aggregation_basis_init", tr)) {
                    XAggB = AggregationGridBasis.CreateSequence(base.MultigridSequence, u.Mapping.BasisS);
                }
                XAggB.UpdateXdgAggregationBasis(this.Op_Agglomeration);

                var      MassMatrix = this.Op_mass.GetMassMatrix(this.u.Mapping, new double[] { 1.0 }, false, this.LsTrk.SpeciesIdS.ToArray());
                double[] _RHSvec    = this.GetRHS();



                Stopwatch stw = new Stopwatch();
                stw.Reset();
                stw.Start();

                Console.WriteLine("Setting up multigrid operator...");

                int p           = this.u.Basis.Degree;
                var MultigridOp = new MultigridOperator(XAggB, this.u.Mapping,
                                                        this.Op_Matrix,
                                                        this.Op_mass.GetMassMatrix(new UnsetteledCoordinateMapping(this.u.Basis), false),
                                                        OpConfig);
                Assert.True(MultigridOp != null);

                int L = MultigridOp.Mapping.LocalLength;
                DOFs = MultigridOp.Mapping.TotalLength;

                double[] RHSvec = new double[L];
                MultigridOp.TransformRhsInto(_RHSvec, RHSvec);


                ISolverSmootherTemplate exsolver;

                SolverFactory SF = new SolverFactory(this.Control.NonLinearSolver, this.Control.LinearSolver);
                List <Action <int, double[], double[], MultigridOperator> > Callbacks = new List <Action <int, double[], double[], MultigridOperator> >();
                Callbacks.Add(CustomItCallback);
                SF.GenerateLinear(out exsolver, MultigridSequence, OpConfig, Callbacks);



                using (new BlockTrace("Solver_Init", tr)) {
                    exsolver.Init(MultigridOp);
                }

                /*
                 * string filename = "XdgPoisson" + this.Grid.SpatialDimension + "p" + this.u.Basis.Degree + "R" + this.Grid.CellPartitioning.TotalLength;
                 * MultigridOp.OperatorMatrix.SaveToTextFileSparse(filename + ".txt");
                 * RHSvec.SaveToTextFile(filename + "_rhs.txt");
                 *
                 * var uEx = this.u.CloneAs();
                 * Op_Agglomeration.ClearAgglomerated(uEx.Mapping);
                 * var CO = new ConvergenceObserver(MultigridOp, MassMatrix, uEx.CoordinateVector.ToArray());
                 * uEx = null;
                 * CO.TecplotOut = "PoissonConvergence";
                 * //CO.PlotDecomposition(this.u.CoordinateVector.ToArray());
                 *
                 * if (exsolver is ISolverWithCallback) {
                 *  ((ISolverWithCallback)exsolver).IterationCallback = CO.IterationCallback;
                 * }
                 * //*/
                XDGField u2 = u.CloneAs();
                using (new BlockTrace("Solver_Run", tr)) {
                    // use solver (on XDG-field 'u2').
                    u2.Clear();
                    MultigridOp.UseSolver(exsolver, u2.CoordinateVector, _RHSvec);
                    Console.WriteLine("Solver: {0}, converged? {1}, {2} iterations.", exsolver.GetType().Name, exsolver.Converged, exsolver.ThisLevelIterations);
                    this.Op_Agglomeration.Extrapolate(u2.Mapping);
                    Assert.IsTrue(exsolver.Converged, "Iterative solver did not converge.");
                }
                stw.Stop();
                mintime   = Math.Min(stw.Elapsed.TotalSeconds, mintime);
                maxtime   = Math.Max(stw.Elapsed.TotalSeconds, maxtime);
                Converged = exsolver.Converged;
                NoOfIter  = exsolver.ThisLevelIterations;

                // compute error between reference solution and multigrid solver
                XDGField ErrField = u2.CloneAs();
                ErrField.Acc(-1.0, u);
                double ERR    = ErrField.L2Norm();
                double RelERR = ERR / u.L2Norm();
                Assert.LessOrEqual(RelERR, 1.0e-6, "Result from iterative solver above threshold.");
            }
        }
        private void RKstageImplicit(double PhysTime, double dt, double[][] k, int s, BlockMsrMatrix[] Mass, CoordinateVector u0, double ActualLevSetRelTime, double[] RK_as, double RelTime)
        {
            Debug.Assert(s < m_RKscheme.Stages);
            Debug.Assert(m_RKscheme.c[s] > 0);
            Debug.Assert(RK_as[s] != 0);

            int Ndof = m_CurrentState.Count;

            // =========
            // RHS setup
            // =========

            m_ImplStParams = new ImplicitStage_AssiParams()
            {
                m_CurrentDt           = dt,
                m_CurrentPhystime     = PhysTime,
                m_IterationCounter    = 0,
                m_ActualLevSetRelTime = ActualLevSetRelTime,
                m_RelTime             = RelTime,
                m_k     = k,
                m_u0    = u0,
                m_Mass  = Mass,
                m_RK_as = RK_as,
                m_s     = s
            };


            // ================
            // solve the system
            // ================

            NonlinearSolver         nonlinSolver;
            ISolverSmootherTemplate linearSolver;

            GetSolver(out nonlinSolver, out linearSolver);


            if (RequiresNonlinearSolver)
            {
                // Nonlinear Solver (Navier-Stokes)
                // --------------------------------

                nonlinSolver.SolverDriver(m_CurrentState, default(double[])); // Note: the RHS is passed as the affine part via 'this.SolverCallback'
            }
            else
            {
                // Linear Solver (Stokes)
                // ----------------------


                // build the saddle-point matrix
                BlockMsrMatrix System, MaMa;
                double[]       RHS;
                this.AssembleMatrixCallback(out System, out RHS, out MaMa, CurrentStateMapping.Fields.ToArray(), true);
                RHS.ScaleV(-1);

                // update the multigrid operator
                MultigridOperator mgOperator = new MultigridOperator(this.MultigridBasis, CurrentStateMapping,
                                                                     System, MaMa,
                                                                     this.Config_MultigridOperator);

                // init linear solver
                linearSolver.Init(mgOperator);

                // try to solve the saddle-point system.
                mgOperator.UseSolver(linearSolver, m_CurrentState, RHS);

                // 'revert' agglomeration
                m_CurrentAgglomeration.Extrapolate(CurrentStateMapping);
            }

            // ================
            // reset
            // ================
            m_ImplStParams = null;
        }
Exemple #3
0
        /// <summary>
        /// Solution of the system
        /// <see cref="LaplaceMtx"/>*<see cref="T"/> + <see cref="LaplaceAffine"/> = <see cref="RHS"/>
        /// using the modular solver framework.
        /// </summary>
        private void ExperimentalSolve(out double mintime, out double maxtime, out bool Converged, out int NoOfIter) {
            using (var tr = new FuncTrace()) {
                int p = this.T.Basis.Degree;
                var MgSeq = this.MultigridSequence;
                mintime = double.MaxValue;
                maxtime = 0;
                Converged = false;
                NoOfIter = int.MaxValue;

                Console.WriteLine("Construction of Multigrid basis...");
                Stopwatch mgBasis = new Stopwatch();
                mgBasis.Start();
                AggregationGridBasis[][] AggBasis;
                using (new BlockTrace("Aggregation_basis_init", tr)) {
                    AggBasis = AggregationGridBasis.CreateSequence(MgSeq, new Basis[] { this.T.Basis });
                }
                mgBasis.Stop();
                Console.WriteLine("done. (" + mgBasis.Elapsed.TotalSeconds + " sec)");


                //foreach (int sz in new int[] { 1000, 2000, 5000, 10000, 20000 }) {
                //    base.Control.TargetBlockSize = sz;

                for (int irun = 0; irun < base.Control.NoOfSolverRuns; irun++) {
                    Stopwatch stw = new Stopwatch();
                    stw.Reset();
                    stw.Start();

                    Console.WriteLine("Setting up multigrid operator...");
                    var mgsetup = new Stopwatch();
                    mgsetup.Start();
                    var MultigridOp = new MultigridOperator(AggBasis, this.T.Mapping, this.LaplaceMtx, null, MgConfig);
                    mgsetup.Stop();
                    Console.WriteLine("done. (" + mgsetup.Elapsed.TotalSeconds + " sec)");


                    Console.WriteLine("Setting up solver...");
                    var solverSetup = new Stopwatch();
                    solverSetup.Start();
                    ISolverSmootherTemplate solver;
                    switch (base.Control.solver_name) {
                        case SolverCodes.exp_direct:
                            solver = new DirectSolver() {
                                WhichSolver = DirectSolver._whichSolver.PARDISO
                            };
                            break;

                        case SolverCodes.exp_direct_lapack:
                            solver = new DirectSolver() {
                                WhichSolver = DirectSolver._whichSolver.Lapack
                            };
                            break;

                        case SolverCodes.exp_softpcg_schwarz_directcoarse: {
                                double LL = this.LaplaceMtx._RowPartitioning.LocalLength;
                                int NoOfBlocks = (int)Math.Max(1, Math.Round(LL / (double)this.Control.TargetBlockSize));
                                Console.WriteLine("Additive Schwarz w. direct coarse, No of blocks: " + NoOfBlocks.MPISum());
                                solver = new SoftPCG() {
                                    m_MaxIterations = 50000,
                                    m_Tolerance = 1.0e-10,
                                    Precond = new Schwarz() {
                                        m_MaxIterations = 1,
                                        //CoarseSolver = new GenericRestriction() {
                                        //    CoarserLevelSolver = new GenericRestriction() {
                                        CoarseSolver = new DirectSolver() {
                                            WhichSolver = DirectSolver._whichSolver.PARDISO
                                            //            }
                                            //}
                                        },
                                        m_BlockingStrategy = new Schwarz.METISBlockingStrategy() {
                                            NoOfPartsPerProcess = NoOfBlocks
                                        },
                                        Overlap = 1,

                                    }
                                };
                                break;
                            }

                        case SolverCodes.exp_softpcg_schwarz: {
                                double LL = this.LaplaceMtx._RowPartitioning.LocalLength;
                                int NoOfBlocks = (int)Math.Max(1, Math.Round(LL / (double)this.Control.TargetBlockSize));
                                Console.WriteLine("Additive Schwarz, No of blocks: " + NoOfBlocks.MPISum());

                                solver = new SoftPCG() {
                                    m_MaxIterations = 50000,
                                    m_Tolerance = 1.0e-10,
                                    Precond = new Schwarz() {
                                        m_MaxIterations = 1,
                                        CoarseSolver = null,
                                        m_BlockingStrategy = new Schwarz.METISBlockingStrategy {
                                            NoOfPartsPerProcess = NoOfBlocks
                                        },
                                        Overlap = 1
                                    }
                                };
                                break;
                            }

                        case SolverCodes.exp_softpcg_mg:
                            solver = MultilevelSchwarz(MultigridOp);
                            break;


                        case SolverCodes.exp_Kcycle_schwarz:
                            solver = KcycleMultiSchwarz(MultigridOp);
                            break;

                        default:
                            throw new ApplicationException("unknown solver: " + this.Control.solver_name);
                    }

                    T.Clear();
                    T.AccLaidBack(1.0, Tex);
                    ConvergenceObserver CO = null;
                    //CO = new ConvergenceObserver(MultigridOp, null, T.CoordinateVector.ToArray());
                    //CO.TecplotOut = "oasch";
                    if (solver is ISolverWithCallback) {

                        if (CO == null) {
                            ((ISolverWithCallback)solver).IterationCallback = delegate (int iter, double[] xI, double[] rI, MultigridOperator mgOp) {
                                double l2_RES = rI.L2NormPow2().MPISum().Sqrt();

                                double[] xRef = new double[xI.Length];
                                MultigridOp.TransformSolInto(T.CoordinateVector, xRef);

                                double l2_ERR = GenericBlas.L2DistPow2(xI, xRef).MPISum().Sqrt();
                                Console.WriteLine("Iter: {0}\tRes: {1:0.##E-00}\tErr: {2:0.##E-00}\tRunt: {3:0.##E-00}", iter, l2_RES, l2_ERR, stw.Elapsed.TotalSeconds);
                                //Tjac.CoordinatesAsVector.SetV(xI);
                                //Residual.CoordinatesAsVector.SetV(rI);
                                //PlotCurrentState(iter, new TimestepNumber(iter), 3);
                            };
                        } else {
                            ((ISolverWithCallback)solver).IterationCallback = CO.IterationCallback;
                        }
                    }


                    using (new BlockTrace("Solver_Init", tr)) {
                        solver.Init(MultigridOp);
                    }
                    solverSetup.Stop();
                    Console.WriteLine("done. (" + solverSetup.Elapsed.TotalSeconds + " sec)");

                    Console.WriteLine("Running solver...");
                    var solverIteration = new Stopwatch();
                    solverIteration.Start();
                    double[] T2 = this.T.CoordinateVector.ToArray();
                    using (new BlockTrace("Solver_Run", tr)) {
                        solver.ResetStat();
                        T2.Clear();
                        var RHSvec = RHS.CoordinateVector.ToArray();
                        BLAS.daxpy(RHSvec.Length, -1.0, this.LaplaceAffine, 1, RHSvec, 1);
                        MultigridOp.UseSolver(solver, T2, RHSvec);
                        T.CoordinateVector.SetV(T2);
                    }
                    solverIteration.Stop();
                    Console.WriteLine("done. (" + solverIteration.Elapsed.TotalSeconds + " sec)");

                    Console.WriteLine("Pardiso phase 11: " + ilPSP.LinSolvers.PARDISO.PARDISOSolver.Phase_11.Elapsed.TotalSeconds);
                    Console.WriteLine("Pardiso phase 22: " + ilPSP.LinSolvers.PARDISO.PARDISOSolver.Phase_22.Elapsed.TotalSeconds);
                    Console.WriteLine("Pardiso phase 33: " + ilPSP.LinSolvers.PARDISO.PARDISOSolver.Phase_33.Elapsed.TotalSeconds);

                    // time measurement, statistics
                    stw.Stop();
                    mintime = Math.Min(stw.Elapsed.TotalSeconds, mintime);
                    maxtime = Math.Max(stw.Elapsed.TotalSeconds, maxtime);
                    Converged = solver.Converged;
                    NoOfIter = solver.ThisLevelIterations;

                    if (CO != null)
                        CO.PlotTrend(true, true, true);

                }
            }
        }