/// <summary>
/// extract the Fields from the solution, Resample them equally spaced and ready to use in an fft
/// </summary>
private void Resample(int iterIndex, double[] currentSol, MultigridOperator Mgop, string component)
{
if (Mgop.GridData.SpatialDimension == 2 && Mgop.LevelIndex == 0)
{
MultidimensionalArray SamplePoints;
GridData GD = (GridData)Mgop.Mapping.AggGrid.AncestorGrid;
BoundingBox BB = GD.GlobalBoundingBox;
double xDist = BB.Max[0] - BB.Min[0];
double yDist = BB.Max[1] - BB.Min[1];
double aspectRatio = xDist / yDist;
MGViz viz = new MGViz(Mgop);
DGField[] Fields = viz.ProlongateToDg(currentSol, "Error");
for (int p = 0; p < Fields.Length; p++)
{
var field = Fields[p];
int DOF = field.DOFLocal;
double N = Math.Sqrt(DOF);
int Nx = (int)Math.Round(Math.Sqrt(aspectRatio) * N);
int Ny = (int)Math.Round(1 / Math.Sqrt(aspectRatio) * N);
SamplePoints = MultidimensionalArray.Create(Ny, Nx);
for (int i = 0; i < Nx; i++)
{
MultidimensionalArray points = MultidimensionalArray.Create(Ny, 2);
for (int k = 0; k < Ny; k++)
{
points[k, 0] = BB.Min[0] + (i + 1) * xDist / (Nx + 1);
points[k, 1] = BB.Min[1] + (k + 1) * yDist / (Ny + 1);
}
List <DGField> fields = new List <DGField>();
fields.Add(field);
FieldEvaluation FE = new FieldEvaluation(GD);
MultidimensionalArray Result = MultidimensionalArray.Create(Ny, 1);
FE.Evaluate(1.0, fields, points, 1.0, Result);
SamplePoints.ExtractSubArrayShallow(-1, i).Acc(1.0, Result.ExtractSubArrayShallow(-1, 0));
}
SamplePoints.SaveToTextFile("ResampleFFT_lvl" + Mgop.LevelIndex + "_" + iterIndex + "_" + component + "_" + field.Identification + ".txt");
}
}
}
/// <summary>
/// defines the problem matrix
/// </summary>
public void Init(MultigridOperator op)
{
this.m_MgOperator = op;
var Mtx = op.OperatorMatrix;
var MgMap = op.Mapping;
viz = new MGViz(op);
if (!Mtx.RowPartitioning.EqualsPartition(MgMap.Partitioning))
{
throw new ArgumentException("Row partitioning mismatch.");
}
if (!Mtx.ColPartition.EqualsPartition(MgMap.Partitioning))
{
throw new ArgumentException("Column partitioning mismatch.");
}
MxxHistory.Clear();
SolHistory.Clear();
double Dim = MgMap.ProblemMapping.GridDat.SpatialDimension;
// set operator
// ============
if (op.CoarserLevel == null)
{
throw new NotSupportedException("Multigrid algorithm cannot be used as a solver on the finest level.");
}
this.OpMatrix = Mtx;
// initiate coarser level
// ======================
if (this.CoarserLevelSolver == null)
{
throw new NotSupportedException("Missing coarse level solver.");
}
this.CoarserLevelSolver.Init(op.CoarserLevel);
// init smoother
// =============
if (PreSmoother != null)
{
PreSmoother.Init(op);
}
if (PostSmoother != null && !object.ReferenceEquals(PreSmoother, PostSmoother))
{
PostSmoother.Init(op);
}
}
