topic Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C in Intel® oneAPI Math Kernel Library

Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

recage — Thu, 19 Nov 2009 14:06:18 GMT

There seems to be an inconsistency in the docs for calling 'dcgmrhs_init' from C: the PDF documentation specifies the parameter 'method' in the function call. However, this parameter does not appear in the C header file.

PDF docs: dcgmrhs_init(n, x, nrhs, b, method, RCI_request, ipar, dpar, tmp)

C header: extern void dcgmrhs_init(MKL_INT *n, double *x, MKL_INT* nRhs, double *b, MKL_INT *rci_request, MKL_INT *ipar, double *dpar, double *tmp);

I understand that 'method' doesn't have any influence on the code, since block CG solution is not yet supported.

Is there a demo code available for 'dcgmrhs' written in C? I can only find the code for Fortran.
For some reason the routine 'dcgmrhs_init' crashes on me. Some demo code would be helpful.

Best regards, Recage

Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

Alexander_K_Intel2 — Thu, 19 Nov 2009 16:00:46 GMT

Quoting - recage

Hi Recage,
We know this problem that appeared while calling cgmhr routines from c code. Itwill be fixed in one of next versions of MKL.

With best regards,

Alexander Kalinkin

Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

recage — Thu, 19 Nov 2009 16:07:24 GMT

Hi Alexander,
thanks for the speedy reply.
Can you please elaborate a little more on this? Apart from the little inconsistency within the documentation for the function 'dcgmrhs_init', is this function callable? In my code it crashes invariably.
Is there a workaround available for the current situation?

Best regards, Recage

Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

Alexander_K_Intel2 — Thu, 19 Nov 2009 16:17:03 GMT

Quoting - recage

Recage,

It's seems that problem is not in documentation, problem is in header file. Parameter "method" not used in that version of cgmrs, but it need to be in interface. Try to change interface on

dcgmrhs_init(MKL_INT *n, double *x, MKL_INT* nRhs, double *b,MKL_INT *method,MKL_INT *rci_request, MKL_INT *ipar, double *dpar, double *tmp);

With best regards,

Alexander Kalinkin

Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

recage — Thu, 19 Nov 2009 16:39:33 GMT

Sir, may I call you Jesus?
Changing the header file solved the problem.
Thanks a lot!!

Re: Iterative Sparse Multiple RHS Solver (dcgmrhs) using with C

Alexander_K_Intel2 — Thu, 19 Nov 2009 16:44:23 GMT

Quoting - recage

Sir, may I call you Jesus?
Changing the header file solved the problem.
Thanks a lot!!

Recage,

Thanks for the good words, you are welcome :)

With best regards,

Alexander Kalinkin