topic Re:Quadratic spline curve construction fails in Intel® oneAPI Math Kernel Library

Quadratic spline curve construction fails

Andrew_Smith — Mon, 15 Jan 2024 18:06:57 GMT

When I try to create a quadratic spline curve, the spline type DF_PP_DEFAULT should be accepted according to the reference help, but is not. It gives error code -1011 (DF_ERROR_BAD_SPLINE_TYPE).

It accepts spline type DF_PP_SUBBOTIN but then the boundary condition type DF_NO_BC should be accepted according to the reference help, but gives error code -1014 (DF_ERROR_BAD_BC_TYPE).

It kind of accepts boundary condition DF_BC_FREE_END but then gives error code -1012 (DF_ERROR_BAD_IC_TYPE). Why is this happening please?

The errors only get raised after the dfdconstruct1d is called and not earlier when calling dfdeditppspline1d where the settings are set. Its odd but not an issue.

Here is test code for the -1012 error:

program Console2 use MKL_DF implicit none real(8), allocatable :: scoeff(:) real(8), parameter :: x(3) = [0.0D0, 8.295D-3, 1.659D-2] real(8), parameter :: y(3) = [6.0D-006, 0.0D0, 6.0D-006] integer errorCode, nx type(DF_TASK) :: task real(8), parameter :: boundary_values(2) = [0D0, 0D0] allocate(scoeff(DF_PP_QUADRATIC*(size(x)-1))) errorCode = 0 nx = size(x) errorCode = dfdnewtask1d(task, nx, x, DF_NO_HINT, 1, y, DF_NO_HINT) if (errorCode /= 0) stop errorCode = dfdeditppspline1d(task, DF_PP_QUADRATIC, DF_PP_SUBBOTIN, DF_BC_FREE_END, boundary_values, scoeff = scoeff) if (errorCode /= 0) stop errorCode = dfdconstruct1d(task, DF_PP_SPLINE, DF_METHOD_STD) print *, errorCode pause end program Console2

Using oneAPI MKL 2024.0 on windows

Re: Quadratic spline curve construction fails

Gennady_F_Intel — Wed, 17 Jan 2024 10:31:18 GMT

It looks like a problem, thanks Andrew.

We will investigate this case.

--Gennady

Re:Quadratic spline curve construction fails

Gennady_F_Intel — Wed, 05 Jun 2024 07:00:04 GMT

Andrew,

1. Default quadratic splines support only DF_BC_Q_VAL as a boundary condition. That's why it reports an error. It needs to set boundary condition explicitly. Following example will work:

errorCode = dfdeditppspline1d(task, DF_PP_QUADRATIC, DF_PP_DEFAULT, DF_BC_Q_VAL, (/1.0D0/), scoeff = scoeff)

2. Only following boundary conditions are supported for Subbotin: free end and combinations of 1st and 2nd derivatives (left, right). DF_NO_BC is not supported

3. Only DF_IC_Q_KNOT internal condition is supported for Subbotin. So, it should be set explicitly in the code. Following example will work:

real(8), parameter :: internal_values(4) = [0D0, (0.0D0 + 8.295D-3) / 2D0, (8.295D-3 + 1.659D-2) / 2D0, 1.659D-2]

...

errorCode = dfdeditppspline1d(task, DF_PP_QUADRATIC, DF_PP_SUBBOTIN, IOR(DF_BC_1ST_LEFT_DER, DF_BC_1ST_RIGHT_DER), (/1.0D0,-1.0D0/), DF_IC_Q_KNOT, internal_values, scoeff = scoeff)

--Gennady