Hello,

I have currently been debugging some code, and was using the flag EIGEN_NO_AUTOMATIC_RESIZING.
Now I ran into an issue that I can't figure out, namely I can't recover the PermutationMatrix from SparseLDLT
using permutationP(). I have attached a simplified code below which works fine if I turn off EIGEN_NO_AUTOMATIC_RESIZING,
but does not work when I turn it on.
Does anybody know what I am doing wrong?

Code: Select all

#include <iostream>
#include <Eigen/Dense>

int main(){
  Eigen::IOFormat CleanFmt(4, 0, ", ", "\n", "[", "]");
  int k = 5;
  Eigen::SparseMatrix<double> A;
  A.resize(k,k);
  A.reserve(Eigen::VectorXi::Constant(k,2));
  for (int j=0; j<k; j++) {
    A.insert(j,j)=1.;
  }
  A.insert(3,0) = .2;
  A.insert(4,3) = -.1;
  A.insert(0,3) = A.coeff(3,0);
  A.insert(3,4) = A.coeff(4,3);
  A.makeCompressed();
  Eigen::SimplicialLDLT<Eigen::SparseMatrix<double> > LDLT(A);
  Eigen::PermutationMatrix<Eigen::Dynamic> perm = LDLT.permutationP();
  Eigen::MatrixXd P = perm.toDenseMatrix().cast<double>();
  std::cout << "A.perm = \n" << P.format(CleanFmt) << std::endl << std::endl;
return(0);
}


Thanks
Jonas Wallin

This works with the devel branch. Let me see what's wrong with the 3.2 branch.

Fixed: https://bitbucket.org/eigen/eigen/commits/9983ae5d038e/