Alex,
Since the InterpolatingFunction
uses Hermite polynomials you can use this method to convert it to a piecewise
function.
Extract the InterpolatingFunction
and use InterpolationToPiecewise
from the above post.
if = skdUstr[[1, 1, 1]] // Head
InterpolationToPiecewise[if, x]
Not sure if that is what you are looking for.