topic Hi, in Intel® oneAPI Math Kernel Library

A runtime error in FEAST zfeast_hcsrgv

dimdol10 — Wed, 22 Aug 2018 00:52:15 GMT

Hello,

I would like to report a runtime error in feast zfeast_hcsrgv routine.

I have utlized the FEAST solver to solve generalized Hermitian eigenvalue problems using the zfeast_hcsrgv routine, but encountered an access violation during running the codes.

I couldn't find any problem in my input data.

An example code is enclosed, and both of two input files, "read_mat_info_1" and "read_mat_info_2", result in runtime errors during calling zfeast_hcsrgv.

Thanks.

Hi,

Jing_Xu — Fri, 24 Aug 2018 02:42:00 GMT

Hi,

I'm not able to open the sln file with VS 2017 and VS 2015, with the following error.

feast_example_runtime_error_2\feast_example_runtime_error_2.vfproj: The application which this project type is based on was not found.

May I know the version of your Visual Studio, please?

Hello,

dimdol10 — Fri, 24 Aug 2018 02:58:06 GMT

Hello,

I'm using the visual studio 2017 15.7.5.

Fortran source file and two input(.txt) files are enclosed.

Thanks.

Hi,

Jing_Xu — Wed, 29 Aug 2018 05:23:56 GMT

Hi,

Thank you for updating the files.

I'll check and get back to you later.

Dear Jing X.,

dimdol10 — Sun, 09 Sep 2018 11:03:00 GMT

Dear Jing X.,

Could you please let me know how it is going?

I'm still in the same trouble. I suspect the input matrices, because those turn out to be not exactly hermitian, but having slight numerical noise giving unsymmetry. I'm not sure that this triggers runtime error in feast, but I couldn't find any other issue in my input.

If it is possible to look inside the feast subroutine, but it must be not allowed to me.

Thanks.

Hello,

dimdol10 — Sun, 09 Sep 2018 13:36:34 GMT

Hello,

I have resolved the problem. As I guessed above, it was due to my input, which turns out to be not exactly hermitian.

I was using the full matrix input (parameter uplo = 'F') to the zfeast_hcsrgv, but that was mistake because my input matrix was not exactly hermitian.

To avoid this trouble, I extract upper triangular part, and then use the option uplo='U'. This works very well.

I found that a slight deviation from the hermitian property in the input due to some numerical noise can trigger a runtime error (access violation) of the zfeast_hcsrgv routine.

Thanks a lot.

Hi,

Jing_Xu — Tue, 11 Sep 2018 00:52:43 GMT

Hi,

I've escalated the issue to engineer team, and waiting for their response.

Glad to hear the problem has been sovled.