private bool extractSeparate(int numCols)
{
if (!computeEigenValues())
{
return(false);
}
// ---- set up the helper to decompose the same tridiagonal matrix
// swap arrays instead of copying them to make it slightly faster
helper.reset(numCols);
diagSaved = helper.swapDiag(diagSaved);
offSaved = helper.swapOff(offSaved);
// extract the orthogonal from the similar transform
V = decomp.getQ(V, true);
// tell eigenvector algorithm to update this matrix as it computes the rotators
vector.setQ(V);
// extract eigenvectors
if (!vector.process(-1, null, null, values))
{
return(false);
}
// the ordering of the eigenvalues might have changed
values = helper.copyEigenvalues(values);
// the V matrix contains the eigenvectors. Convert those into column vectors
eigenvectors = CommonOps_DDRM.rowsToVector(V, eigenvectors);
return(true);
}
private bool extractTogether()
{
// extract the orthogonal from the similar transform
V = decomp.getQ(V, true);
// tell eigenvector algorithm to update this matrix as it computes the rotators
helper.setQ(V);
vector.setFastEigenvalues(false);
// extract the eigenvalues
if (!vector.process(-1, null, null))
{
return(false);
}
// the V matrix contains the eigenvectors. Convert those into column vectors
eigenvectors = CommonOps_DDRM.rowsToVector(V, eigenvectors);
// save a copy of them since this data structure will be recycled next
values = helper.copyEigenvalues(values);
return(true);
}