### Zero solution with cula sparse

Posted:

**Tue May 07, 2013 5:23 am**First of all greetings to everyone, and thank you very much for this great piece of software.

Now to the point of the topic. The title is abstract but i can't think of a more suitable title now.

I am working on a project for my university and what i am supposed to do is to replace a serial program (written in fortran) that solves a Ax=b specified problem using gauss elimination. A is a sparse matrix and so what would be the best way to solve this problem other than using CULA Sparse.

I've kept the initial code because it contains some subroutines that would cost me a lot of time to rewrite in C, and as soon as CULA Sparse has modules for fortran, i continued to write my code in fortran.

I think i've called CULA correctly because i get no runtime or data error. But the output of CULA is this:

b matrix is initially zero and after the "solution" x is also zero...

Can i somehow indicate the cause of this "failure" ?

Thanks in advance.

Now to the point of the topic. The title is abstract but i can't think of a more suitable title now.

I am working on a project for my university and what i am supposed to do is to replace a serial program (written in fortran) that solves a Ax=b specified problem using gauss elimination. A is a sparse matrix and so what would be the best way to solve this problem other than using CULA Sparse.

I've kept the initial code because it contains some subroutines that would cost me a lot of time to rewrite in C, and as soon as CULA Sparse has modules for fortran, i continued to write my code in fortran.

I think i've called CULA correctly because i get no runtime or data error. But the output of CULA is this:

Solver: Cg

Flag: Converged successfully in 1 iterations

Residual: nan

Total Time: 0.005367s (overhead + solve)

Overhead: 0.001329s

Solve: 0.004035s

b matrix is initially zero and after the "solution" x is also zero...

Can i somehow indicate the cause of this "failure" ?

Thanks in advance.