Hello,
I'm using the data fitting functions of MKL for cubic spline interpolation (DF_PP_CUBIC, DF_PP_DEFAULT) using a not-a-knot condition (DF_BC_NOT_A_KNOT). In theory at least 4 samples are needed to perform this kind of interpolation, which is the unique cubic interpolation polynomial in this case.
My question is: What is the result of the MKL routine in case of 3 samples, which can also be executed without error code? Is this undefined behavior?
The MATLAB routine interp1 performs a simple quadratic polynomial interpolation for example. But this result differs from MKL's.
Thanks for clarification