How can I differentiate a spline using a finite difference scheme?

[karmko]

Hello
I have made a simple spline(x,y) of 4 datapoints and I want to differentiate it.
I can't get it to work; I have tried fntlr, fnder ect.

Can anyone help?
Karin

 

[LeBrad]

I can't get it to work; I have tried fntlr, fnder ect.

Have you tried shouting at it?


What program are you using? Don't bother with built in functions, just use a finite different scheme and find it yourself. Are you familiar with those?

 

[ravenprp]

Hello Karin,

To differentiate a spline using a finite difference scheme, you can use the following steps:

1. Define your spline function using the 4 datapoints. Let's call it f(x).

2. Choose a small step size, h, for your finite difference scheme. This will be the distance between two adjacent points on your spline.

3. Use the central difference formula to calculate the derivative of f(x) at each point. This formula is given by:

f'(x) = [f(x+h) - f(x-h)] / 2h

4. Repeat this calculation for all the points on your spline.

5. The result will be an approximation of the derivative of your spline at each point. You can plot this to get an idea of the slope of your spline at different points.

I hope this helps! Let me know if you have any further questions or if you need clarification on any of the steps.