FGMRES for pentadiagonal matrix

[Elsayed_A_]

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

[Gennady_F_Intel]

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

[Elsayed_A_]

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.

[Gennady_F_Intel]

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