Extrapolation method used in interpn

Hi,

which extrapolation method uses interpn with 'spline' selected?

Thanks, Peter

Answer 1

[Walter Roberson]

http://www.mathworks.com/help/matlab/ref/interp1.html#input_argument_method

"Spline interpolation using not-a-knot end conditions. The interpolated value at a query point is based on a cubic interpolation of the values at neighboring grid points in each respective dimension."

[Peter]

Thanks, but I am asking about extrapolation, not interpolation. I know that interpn does extrapolate if I evaluate the spline outside its domain, but I can't find the extrapolation method (linear, Richardson,...) in the documentation.

Thanks, Peter