I'm attempting to understand how B-Spline derivatives work.
To do this, i've generated some data in MATLAB to plot sin(x) over 0 - 2*pi. I then use the splinetool to fit an order 2 spline to the data which it fits perfectly. However, when I look at the 1st derivative of this sine wave data it's max is 0.017 and it's min is -0.017.
I don't understand why the derivative of this data doesn't give exactly cos(x) with a max and min of 1, -1. Any insights please?