Pardiso error = -7 diagonal matrix problem

[xdominique]

Hi!

When using Pardiso, I got an error : diagonal matrix problem. What does that mean? There are numbers on the diagonale that are not correct? There is a zero pivot? How can I solve this?

Thanks and have a good day!

[Konstantin_A_Intel]

Hi,

This error means that your matrix is singular, namely, 7th element is zero. If you want to solve this matrix, please try to perturb all zero diagonal elements with some small non-zero value (1e-16 for example).

Diagonal matrices are handled separately in PARDISO: in particular, we make more checks for this type of matrices such as checking for singularity that is not possible for non-diagonal matrices. But it's definitely a gap in MKL PARDISO documentation, we will try to fix it.

Please fell free to ask more questions!

Regards,

Konstantin

[Konstantin_A_Intel]

One more note:

In fact, PARDISO is purposed for solving non-singular matrices and solving the matrix with the pertrubed diagonal elements is not completely correct. Even if the system will be solved there's no guaranty that produced solution will be unique.

You may also attach the matrix if you want we make a bit more analisys.

Regards,

Konstantin