Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

How to scale discrete differential equations

Status
Not open for further replies.
P

pontotochs

Newbie level 3
Joined
May 9, 2006
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,320
Hi,
It is easy to do the derivative of sampled data by doing something like
[X(n) - X(n-1)]/Δt, however, what do you do to make sure the answer is scaled correctly?
For example if you take a 10 Hz sine wave (+/- 1) and sample it at 25 Hz, then do the derivative- as above, you will get a cosine, but the amplitude will be off, increase the sample rate and you will get a different answer.

Thanks
 

Your equation is in the formation of a difference equation, as opposed to a differential.
If you are STUCK with finite sampled data, I can give you a formulation for the derivative of a bandlimited signal, but if not, we need to dig more deeply into the problem.
(by the way - the phenominon you spotted is quite real)
 

I am stuck with sampled, band-limited data, therefore I would be interested in your formulation for the derivative.

Thanks for your help
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top