natural cubic spline interpolation of y-values: how to get derivative of the spline wrt the y-values?

Technical Source
2 min readMar 16, 2023

--

Given a data set with support points x_1,…,x_n and corresponding y-values y_1,…,y_n.

My objective is to create a cubic spline f (with natural boundary conditions) that passes through the y_values. There are, of course, plenty of functions for doing this.

However, for a parameter identification procedure, I have to compute the derivative of the spline f with respect to the y-values — at arbitrary points within [x1, x_n].

Is there an easy way using built-in functions of Matlab to compute the sensitivities?

NOTE:-

Matlabsolutions.com provide latest MatLab Homework Help,MatLab Assignment Help , Finance Assignment Help for students, engineers and researchers in Multiple Branches like ECE, EEE, CSE, Mechanical, Civil with 100% output.Matlab Code for B.E, B.Tech,M.E,M.Tech, Ph.D. Scholars with 100% privacy guaranteed. Get MATLAB projects with source code for your learning and research.

x=cumsum(rand(1,10));
y=rand(size(x));
xi=linspace(min(x),max(x),500);
f=ppval(spline(x,y),xi)
f = 1×500
0.8578 0.8215 0.7861 0.7516 0.7180 0.6852 0.6533 0.6223 0.5920 0.5627 0.5341 0.5063 0.4794 0.4532 0.4278 0.4032 0.3794 0.3563 0.3340 0.3124 0.2915 0.2714 0.2519 0.2332 0.2152 0.1978 0.1812 0.1652 0.1498 0.1351
plot(x,y,'or',xi,f,'b') %

SEE COMPLETE ANSWER CLICK THE LINK

--

--

Technical Source
Technical Source

Written by Technical Source

Simple! That is me, a simple person. I am passionate about knowledge and reading. That’s why I have decided to write and share a bit of my life and thoughts to.

No responses yet