/**
* Computes and applies the fill reduction permutation. Either A is returned (unmodified) or the permutated
* version of A.
* @param A Input matrix. unmodified.
* @return A permuted matrix. Might be A or a different matrix.
*/
public DMatrixSparseCSC apply(DMatrixSparseCSC A)
{
if (fillReduce == null)
{
return(A);
}
fillReduce.process(A);
IGrowArray gp = fillReduce.getRow();
if (pinv.Length < gp.Length)
{
pinv = new int[gp.Length];
}
CommonOps_DSCC.permutationInverse(gp.data, pinv, gp.Length);
if (symmetric)
{
CommonOps_DSCC.permuteSymmetric(A, pinv, Aperm, gw);
}
else
{
CommonOps_DSCC.permuteRowInv(pinv, A, Aperm);
}
return(Aperm);
}
//@Override
public DMatrixSparseCSC getQ(DMatrixSparseCSC Q, bool compact)
{
if (Q == null)
{
Q = new DMatrixSparseCSC(1, 1, 0);
}
if (compact)
{
Q.reshape(V.numRows, n, 0);
}
else
{
Q.reshape(V.numRows, m, 0);
}
DMatrixSparseCSC I = CommonOps_DSCC.identity(V.numRows, Q.numCols);
for (int i = V.numCols - 1; i >= 0; i--)
{
QrHelperFunctions_DSCC.rank1UpdateMultR(V, i, beta[i], I, Q, gwork, gx);
I.set(Q);
}
// Apply P transpose to Q
CommonOps_DSCC.permutationInverse(structure.pinv, structureP, V.numRows);
CommonOps_DSCC.permuteRowInv(structureP, Q, I);
// Remove fictitious rows
if (V.numRows > m)
{
CommonOps_DSCC.extractRows(I, 0, m, Q);
}
else
{
Q.set(I);
}
return(Q);
}
