Hello,
After looking into the sources, the SPQR interface is less developped
than the SparseQR one.
For example, the assignment operator used in Q = qr.matrixQ() is
defined in SparseQR interface but not in SPQR (which explains the error
I have reported). In addition, in SPQR the multiplication of
qr.matrixQ() by another object is defined only for dense vectors. On the
typical use cases I am testing, SuiteSparse SPQR implementation is 5
times faster than Eigen's SparseQR, so the SuiteSparse interface is
worth being improved!
S.
On 3/5/24 18:01, Rasmus Munk Larsen wrote:
Sameer, Do you have any advice here?
On Tue, Mar 5, 2024 at 1:00 AM Stéphane Mottelet
<[email protected]> wrote:
Hello,
I have a code using regular SparseQR working fine (within a Scilab
gateway):
typedef Eigen::SparseMatrix<double, 0x1, int> RealSparse_t;
types::Sparse *pSpA = in[0]->getAs<types::Sparse>();
types::Sparse::RealSparse_t* sp0 = pSpA->matrixReal;
Eigen::SparseQR <types::Sparse::RealSparse_t,
Eigen::COLAMDOrdering<int> > qr;
qr.compute(*sp0);
pOutR = new types::Sparse(new
types::Sparse::RealSparse_t(qr.matrixR()),NULL);
out.push_back(pOutR);
Eigen::SparseMatrix<double> Q;
Q = qr.matrixQ();
pOutQ = new types::Sparse(new
types::Sparse::RealSparse_t(Q),NULL);
out.push_back(pOutQ);
I wanted to test SuiteSparse SPQR instead, but the mechanism to
recover
the Householdr reflection list qr.matrixQ() as a regular matrix
does not
seem to be supported, as the almost same as above following code
(Eigen::SparseQR is replaced by Eigen::SPQR and header include (not
shown here) is also updated)
typedef Eigen::SparseMatrix<double, 0x1, int> RealSparse_t;
types::Sparse *pSpA = in[0]->getAs<types::Sparse>();
types::Sparse::RealSparse_t* sp0 = pSpA->matrixReal;
Eigen::SPQR <types::Sparse::RealSparse_t> qr;
qr.compute(*sp0);
pOutR = new types::Sparse(new
types::Sparse::RealSparse_t(qr.matrixR()),NULL);
out.push_back(pOutR);
Eigen::SparseMatrix<double> Q;
Q = qr.matrixQ();
pOutQ = new types::Sparse(new
types::Sparse::RealSparse_t(Q),NULL);
out.push_back(pOutQ);
does not compile and yields the following error (SPQR updated code
compiles and runs fine when extracting R only):
error: no viable overloaded '='
Q = qr.matrixQ();
How can I recover the Q matrix when using SuiteSparse SPQR ?
Thanks for your help.
--
Stéphane Mottelet
Ingénieur de recherche HDR
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688 <tel:+33%203%2044%2023%2046%2088>
http://www.utc.fr/~mottelet
<https://antiphishing.vadesecure.com/v4?f=RWp5bEt5cWRvWHZLUzFDRMPAbgQqTi_Twvc24wFCNi0cD555ASVet1ojx_UaBxT5&i=RGlHYzhiRkNBWWxzVkd3ZZXoyxOFFwxcFvJQWRQCipI&k=gA0E&r=dkFaMlN1eld3UHl5NHhOVGIe9smcmSFMfwNZ5uQBEk8bbulNeA9CneplwcnM9UVa&s=bf13500add801819c20e1aafd6e6bb3c3602f2f9f2e144358c8ddd22219512d5&u=http%3A%2F%2Fwww.utc.fr%2F~mottelet>
--
Stéphane Mottelet
Ingénieur de recherche HDR
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet
