/// <summary>
/// collects all locally stored rows of matrix <paramref name="M"/>
/// </summary>
static public MsrMatrix.MatrixEntry[][] GetAllEntries(this IMutableMatrixEx M)
{
int i0 = (int)(M.RowPartitioning.i0), L = M.RowPartitioning.LocalLength;
MsrMatrix.MatrixEntry[][] ret = new MsrMatrix.MatrixEntry[L][];
double[] val = null;
int[] col = null;
int Lr;
for (int i = 0; i < L; i++)
{
//ret[i] = M.GetRow(i + i0);
Lr = M.GetRow(i + i0, ref col, ref val);
var row = new MsrMatrix.MatrixEntry[Lr];
for (int lr = 0; lr < Lr; lr++)
{
row[lr].m_ColIndex = col[lr];
row[lr].Value = val[lr];
}
ret[i] = row;
}
return(ret);
}
/// <summary>
/// accumulates a dense matrix <paramref name="FullMtx"/> to a sparse matrix
/// -- certainly, only adviseable for small matrices.
/// </summary>
static public void AccDenseMatrix(this IMutableMatrixEx tis, double alpha, IMatrix FullMtx)
{
if (tis.RowPartitioning.LocalLength != FullMtx.NoOfRows)
{
throw new ArgumentException("Mismatch in number of rows.");
}
if (tis.ColPartition.TotalLength != FullMtx.NoOfCols)
{
throw new ArgumentException("Mismatch in number of columns.");
}
int i0 = tis.RowPartitioning.i0;
int I = tis.RowPartitioning.LocalLength;
int J = tis.ColPartition.TotalLength;
int[] col = null;
double[] val = null;
for (int i = 0; i < I; i++)
{
int Lr = tis.GetRow(i + i0, ref col, ref val);
var oldRow = new MsrMatrix.MatrixEntry[Lr];
for (int lr = 0; lr < Lr; lr++)
{
oldRow[i].m_ColIndex = col[lr];
oldRow[i].Value = val[lr];
}
List <int> NewColIdx = new List <int>(J);
List <double> NewVals = new List <double>(J);
for (int j = 0; j < J; j++)
{
double FMij = FullMtx[i, j];
if (FMij != 0.0)
{
NewVals.Add(alpha * FMij);
NewColIdx.Add(j);
}
}
Array.Sort <MsrMatrix.MatrixEntry>(oldRow);
int k1 = 0, k2 = 0, K1 = oldRow.Length, K2 = NewVals.Count;
while (k1 < K1 && k2 < K2)
{
int j1 = oldRow[k1].m_ColIndex;
int j2 = NewColIdx[k2];
if (j1 < 0)
{
// should also chrash in RELEASE, therefor -> Exception.
throw new ApplicationException("expecting a row without un-allocated entries.");
}
if (j1 > j2)
{
//
k2++; // new row neds to catch up
}
else if (j1 < j2)
{
k1++;
}
else
{
NewVals[k2] += oldRow[k1].Value;
k1++;
k2++;
}
}
tis.SetValues(i + i0, NewColIdx.ToArray(), NewVals.ToArray());
}
}
