topic Per my continued testing, in Intel® oneAPI Math Kernel Library

strnlspbc_solve divide by zero

Scott_w_ — Thu, 24 Apr 2014 04:45:13 GMT

I'm running MKL 11 Update 3 and am getting a floating point divide by zero exception at _mkl_trs_dmintr_ls_lc() + 0x10a1 from a call to strnlspbc_solve. I'm using LS to fit a Gaussian, and the code works for many cases and I've validated it when data generated from a Gaussian. When it fails, it occurs after a number of loops through the RCI loop.

Per my continued testing,

Scott_w_ — Thu, 24 Apr 2014 16:22:32 GMT

Per my continued testing, this problem doesn't occur in the "without boundary conditions" version of the solver.

There must be something

mecej4 — Thu, 24 Apr 2014 16:59:00 GMT

There must be something about the specific problem to which you are applying this solver, or something specific about how you call the solver in your code, which causes the failure of the solver.

There is an example code provided with MKL, called ex_nlsqp_bc_f.f, and that example runs without errors.

Therefore, not much can be done or said until you provide example code that displays the same problems that you reported.

Thanks for your feedback.

Scott_w_ — Thu, 24 Apr 2014 17:26:15 GMT

Thanks for your feedback.

I think the function name and "divide by zero" error provides a tremendous amount of information, likely enough to find the bug. I'm tempted to say a robust solver (which is the whole idea behind TR methods) should be guarding against divide by zero error.

I'll do some more investigation and then see if I can pull together an example.

Attached is a sample VC++

Scott_w_ — Thu, 24 Apr 2014 20:47:00 GMT

Attached is a sample VC++ project that illustrates the problem.

Important: the code failure is dependent on the _EM_ZERODIVIDE mask being cleared, which suggests a work-around. However, I don't know whether the code can be trusted to provide accurate results when the zero divide mask is set.

Hi, when can I expect that

Scott_w_ — Mon, 28 Apr 2014 18:57:44 GMT

Hi, when can I expect that someone from Intel will take a look at this?

I was trying to compiling: ".

Gennady_F_Intel — Tue, 06 May 2014 03:47:38 GMT

I was trying to compiling: "...fatal error C1083: Cannot open include file: 'PSNumeric.h': No such file or directory"

Thanks for taking a look at

Scott_w_ — Tue, 06 May 2014 15:55:40 GMT

Thanks for taking a look at this. You can remove the #include directive for PSNumeric.h, it builds without it.

ok, I see you submitted the

Gennady_F_Intel — Wed, 07 May 2014 03:13:41 GMT

ok, I see you submitted the same topic to the intel premier support and my colleague reproduced the problem on her side. Stay tuned.