Thread: Cubic Spline Interpolation...Wtf I don't understand

I have a data:

0.5--0.000346
1.0--0.046467
1.5--0.219274
2.0--0.358386
2.5--0.418706
3.0--0.439846
3.5--0.44676
4.0--0.448971

They ask do cubic spline to interpolate the inflection point. I don't understand anything. Whoever invented cubic spline was a math nerd or something, I'm an engineer and I don't understand.

I'll tell you what I do understand. I understand that I need N-1 cubic equations, 1 in between each point, and for each equation I need to find a,b,c and d. I already used a cubic approximation around the inflection point successfully but that's only one equation for all the points...cubic spline is several equations, 1 in between each point so it's not cubic spline.

Can someone show me how this works or give me a link to a NUMERICAL, STEP BY STEP example?

Thanks guys!