RE: [eigen] JacobiSVD::compute does malloc for non-square matrices

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Thank you! I will give a try. Do I have to apply all patches or only "part 4: Removes heap allocations from JacobiSVD and its preconditioners" ?
 
Philippe


De : Listengine [mailto:listengine@xxxxxxxxxxxxxxxxx] De la part de Adolfo Rodríguez Tsouroukdissian
Envoyé : 18 mai 2011 11:55
À : eigen@xxxxxxxxxxxxxxxxxxx
Objet : Re: [eigen] JacobiSVD::compute does malloc for non-square matrices

On Wed, May 18, 2011 at 5:24 PM, <hamelin.philippe@xxxxxxx> wrote:
Hello,
 
I'm trying to use the SVD in a real-time process, so I can't do any malloc. I found that my SVD (JacobiSVD) was doing some malloc, even when the pre-allocation ctor is used. The jacobi unit tests (jacobisvd_preallocate) does make this validation, but only for a square 3x3 matrix. The same test fail when using non-square matrices. Here is an example of a failing test:
 
bool testSVDNoMalloc()
{
    const int rows = 15;
    const int cols = 15;
 
    Eigen::MatrixXd A = Eigen::MatrixXd::Random(rows, cols);
 
    Eigen::JacobiSVD<Eigen::MatrixXd> svd1(rows, cols);
    Eigen::internal::set_is_malloc_allowed(false);
    svd1.compute(A);
    Eigen::internal::set_is_malloc_allowed(true);
 
    return true;
}
 
Is this a bug or maybe I misunderstood something?

Philippe,

There is an open bug [1] with patches that fix heap allocations for the JacobiSVD::compute method. However, some of them are still pending for review, hence have not yet been integrated in the dev branch. If you feel brave, feel free to give them a test drive. They work for me, and don't have side effects as per the unit tests.

As a side note which might be of interest, once bug 206 is closed, I'd like to take on fixing heap allocations on JacobiSVD::solve method, plus propose adding a mechanism for generalizing the computation of the inverse of the singular values, so that one can not only perform pure least squares inverses/linear system solve, but also add other criteria to the optimization (eg. regularization).

[1] http://eigen..tuxfamily.org/bz/show_bug.cgi?id=206

HTH,

Adolfo
 
 
Thank you,
 
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