topic Hi Aaron, in Intel® oneAPI Math Kernel Library

mkl_ddiamv example

Aaron_B_1 — Thu, 18 Jun 2015 19:43:38 GMT

I have some problems with using mkl_ddiamv (language C). Can anybody show me a code example of using mkl_ddiamv with initialization of all the input formal parametres? It is desirable to use the number of diagonals more than one. For example, 3-diagonals with offset=[-1 0 1] and size 5 by 5 with all elements are ones.Multiplicated vectors are ones too. In different sources the matrix in special diag format is treated as two-dimensional array or one-dimensional array with row-by-row storage.

Hi Aaron,

Ying_H_Intel — Fri, 19 Jun 2015 07:57:15 GMT

Hi Aaron,

There is mkl_sdia.c sample under mkl example directory. you may refer to it first and let us know if any problem.

Best Regards,
Ying

Quote:Ying H (Intel) wrote:

Aaron_B_1 — Fri, 19 Jun 2015 20:21:24 GMT

Ying H (Intel) wrote:

Hi Aaron,

There is mkl_sdia.c sample under mkl example directory. you may refer to it first and let us know if any problem.

Best Regards,
Ying

Thank you very much! I handle with my problem using your code example. Thank you!

I have one more strange

Aaron_B_1 — Sun, 21 Jun 2015 14:35:20 GMT

I have one more strange question.

In my project's properties I set "Use Intel MKL" to "Parallel". The majority of time of my programm is matrix-vector multiplication, which is performed by mkl_ddiamv. In my task manager I always see, that only one thread is busy by my programm process. I use Intel C++ Compiler 14.0. I try to take many different sizes of multiplicated arrays. There is no difference. I unsuccessfully tried to find some info about the reason of one-thread calculation.

Is it normal behavior of this function or I do something wrong? Should I change some of my project's properties or include something to launch my app multy-threated?

Hi Aaron,

Ying_H_Intel — Wed, 24 Jun 2015 01:22:24 GMT

Hi Aaron,

Level 2 for DIA format is not threaded till current versions of MKL. You may try csr format if needed. I will update the thread function list in https://software.intel.com/en-us/articles/intel-mkl-threaded-functions/

Thank

Ying