topic FGMRES for pentadiagonal matrix in Intel® oneAPI Math Kernel Library

FGMRES for pentadiagonal matrix

Elsayed_A_ — Sun, 23 Oct 2016 17:29:45 GMT

Hello,

I am new to Fortran intel MKL. I am trying to use the FGMRES with ILUT preconditioner for solving the Penta diagonal matrix (A*x=b.) resulting from discretization of 3D convection-diffusion equation. The coefficient matrix is naturally stored in a band format.

Since ILUT is using CSR storage, how can I convert the band storage format to CSR format?

Also, for matrix-vector multiplication step, for my case do I have to multiply inv(A)*b? I am confused about this.

Regards,

Elsayed

you may try to convert from

Gennady_F_Intel — Mon, 24 Oct 2016 03:50:12 GMT

you may try to convert from band to dense representation and then call mkl_ddnscsr to convert from dense to CSR format

Gennady,

Elsayed_A_ — Mon, 24 Oct 2016 03:57:00 GMT

Gennady,

Thanks for your prompt reply. Actually, this is what I am doing. My question then is how to convert from band to dense representation.

at this moment, MKL doesn't

Gennady_F_Intel — Mon, 24 Oct 2016 09:40:01 GMT

at this moment, MKL doesn't provide such sort of conversion routine