Interpolation export feature

[Simsso]

Moving the comment by "Vasily" from the blog post to this issue:

[...] it would be nice if you could add an option to save the resulting data to a file, for example, for every interval you can save it in 9 equally spaced points inside, so for N initial points the output will be 10*(N-1)+1 points.

This issue corresponds to that feature request.