I have tested m==n case with the latest version of Eigen from the repository.
No errors. Sorry (must always sync my working rep).
I.
However out-of-bounds errors still appear (m==n).
Basically such errors detected at the following two lines:
solver.compute(A);
....
DenseMatrixType X = solver.solve(B);
Compiled & diagnosed by ICC 13.1 in Debug x64 build with /Qcheck-pointers:rw
II.
Question about SparseMatrix & custom scalars.
In my recent commits to Eigen I have fixed some issues with non-POD scalars support.
However there are some parts in Sparse module which are still non-compatible with non-POD scalars.
AmbiVector in particular. Its implementation has pretty convoluted logic, I am not able to fix it in short time.
Would appreciate any help from core developers in this regard.
III.
I believe case of m < n is very important to support in SparseQR.
Dense QR has such support. Octave's SparseQR also has such support.
I will provide any help in this regard.
Thank you,
Pavel.