This video, a continuation of [maternr1EN], discusses the Matérn cases of
spectral factor of order 2 and 3. When the correlation distance
increases, the interpolated mean tends to be a cubic spline (in case of order 2
spectral factor) and a quintic spline (in case of order 3), respectively.
The final part of the video presents an example of fractional order
() of
the spectral factor (this motivates definitions of ’fractional derivatives’ in
literature, which are not the subject of this material), and an example with a
quadratic exponential kernel, which is the Matérn limit when the order of the
spectral factor tends to infinity (whose interpolation would be infinitely
differentiable), as discussed in video [maternEN].