Radius of curvature calculation

I have a set of lines/curves ( discontinuous lines) from which i revolve them to get a surface. I need to find the principle curvatures on this surface. As i understand, to calculate the principle curvatures you would require the analytical equation. But i have only a numerical representation of the base curve. How do i go about in doing this?

Answer 1

[Jan]

While gradient() replies the slope, gradient(gradient()) determines 2nd derivative. The signed curvature is defined as:

k = y'' / (1 + y'^2)^1.5

with primes mean the derivative to x here.