/// <summary>
/// computes the residual on this level.
/// </summary>
public void Residual <V1, V2, V3>(V1 rl, V2 xl, V3 bl)
where V1 : IList <double>
where V2 : IList <double>
where V3 : IList <double>
{
OpMatrix.SpMV(-1.0, xl, 0.0, rl);
rl.AccV(1.0, bl);
}
/// <summary>
/// Tests if a matrix (associated with some operator) depends only on values in this sub-grid,
/// or not.
/// </summary>
/// <param name="_Mtx">some operator matrix</param>
/// <param name="RowMap">row-/co-domain mapping for matrix <paramref name="_Mtx"/></param>
/// <param name="ColMap">column/domain mapping for matrix <paramref name="_Mtx"/></param>
/// <param name="NoOfTests"></param>
/// <returns>
/// 0.0 if there is no dependency of the matrix <paramref name="_Mtx"/>
/// on values outside of this subgrid.
/// </returns>
public double TestMatrixDependency(MsrMatrix _Mtx, UnsetteledCoordinateMapping RowMap, UnsetteledCoordinateMapping ColMap, int NoOfTests = 10)
{
Random RND = new Random();
if (!_Mtx.RowPartitioning.Equals(RowMap))
{
throw new ArgumentException();
}
if (!_Mtx.ColPartition.Equals(ColMap))
{
throw new ArgumentException();
}
var Mtx = new ilPSP.LinSolvers.monkey.CPU.RefMatrix(_Mtx);
int[] IR = RowMap.BasisS.Count.ForLoop(i => i);
int[] IC = ColMap.BasisS.Count.ForLoop(i => i);
var SgrdRow = RowMap.GetSubvectorIndices(this, true, IR);
var SgrdCol = SgrdRow; // ColMap.GetSubvectorIndices(this, true, true, IC);
double[] X0 = new double[ColMap.LocalLength];
double[] Y0 = new double[RowMap.LocalLength];
for (int i = 0; i < X0.Length; i++)
{
X0[i] = RND.NextDouble();
}
Mtx.SpMV(1.0, X0, 0.0, Y0);
int i0Row = RowMap.i0;
int i0Col = ColMap.i0;
int iECol = ColMap.iE;
double err = 0;
for (int iTest = 0; iTest < NoOfTests; iTest++)
{
double[] X1 = new double[ColMap.LocalLength];
double[] Y1 = new double[RowMap.LocalLength];
for (int i = 0; i < X0.Length; i++)
{
X1[i] = RND.NextDouble();
}
foreach (int i in SgrdCol)
{
if (i >= i0Col && i < iECol)
{
X1[i - i0Col] = X0[i - i0Col];
}
}
Mtx.SpMV(1.0, X1, 0.0, Y1);
foreach (int k in SgrdRow)
{
double Y1k = Y1[k - i0Row];
double Y0k = Y0[k - i0Row];
//Debug.Assert((Y0k - Y1k).Pow2() < 1.0e-8);
err += (Y0k - Y1k).Pow2();
}
}
return(err.MPISum());
}
