public virtual bool decompose(FMatrixRBlock orig)
{
if (orig.numCols != orig.numRows)
{
throw new ArgumentException("Input matrix must be square.");
}
init(orig);
FSubmatrixD1 subA = new FSubmatrixD1(A);
FSubmatrixD1 subV = new FSubmatrixD1(V);
FSubmatrixD1 subU = new FSubmatrixD1(A);
int N = orig.numCols;
for (int i = 0; i < N; i += A.blockLength)
{
// Console.WriteLine("-------- triag i "+i);
int height = Math.Min(A.blockLength, A.numRows - i);
subA.col0 = subU.col0 = i;
subA.row0 = subU.row0 = i;
subU.row1 = subU.row0 + height;
subV.col0 = i;
subV.row1 = height;
subV.original.reshape(subV.row1, subV.col1, false);
// bidiagonalize the top row
TridiagonalHelper_FDRB.tridiagUpperRow(A.blockLength, subA, gammas, subV);
// apply Householder reflectors to the lower portion using block multiplication
if (subU.row1 < orig.numCols)
{
// take in account the 1 in the last row. The others are skipped over.
float before = subU.get(A.blockLength - 1, A.blockLength);
subU.set(A.blockLength - 1, A.blockLength, 1);
// A = A + U*V^T + V*U^T
multPlusTransA(A.blockLength, subU, subV, subA);
multPlusTransA(A.blockLength, subV, subU, subA);
subU.set(A.blockLength - 1, A.blockLength, before);
}
}
return(true);
}
