/// <summary>
/// Local condition number formed by the block of each cell and its neighbors.
/// </summary>
/// <returns>
/// one value per cell:
/// - index: local cell index
/// - content: condition number (one norm) of the local stencil
/// </returns>
public double[] StencilCondNumbers()
{
using (new FuncTrace()) {
int J = m_map.LocalNoOfBlocks;
Debug.Assert(J == m_map.GridDat.iLogicalCells.NoOfLocalUpdatedCells);
var Mtx = m_MultigridOp.OperatorMatrix;
Debug.Assert(Mtx._ColPartitioning.LocalNoOfBlocks == J);
Debug.Assert(Mtx._RowPartitioning.LocalNoOfBlocks == J);
var grd = m_MultigridOp.Mapping.AggGrid;
double[] BCN = new double[J];
for (int j = 0; j < J; j++)
{
var LocBlk = grd.GetCellNeighboursViaEdges(j).Select(t => t.Item1).ToList();
LocBlk.Add(j);
for (int i = 0; i < LocBlk.Count; i++)
{
if (LocBlk[i] >= J)
{
LocBlk.RemoveAt(i);
i--;
}
}
var Sel = new SubBlockSelector(m_MultigridOp.Mapping);
Sel.VariableSelector(this.VarGroup);
Sel.CellSelector(LocBlk, global: false);
var Mask = new BlockMask(Sel);
MultidimensionalArray[,] Blocks = Mask.GetFullSubBlocks(Mtx, ignoreSpecCoupling: false, ignoreVarCoupling: false);
MultidimensionalArray FullBlock = Blocks.Cat();
BCN[j] = FullBlock.Cond('I');
}
return(BCN);
}
}