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.

How to compute derivatives of discrete data in Matlab?

Status
Not open for further replies.

smithchart

Member level 5
Joined
Aug 10, 2004
Messages
89
Helped
24
Reputation
48
Reaction score
19
Trophy points
1,288
Activity points
1,308
matlab derivative of data

Hello:

I need to compute derivatives of complex discrete data in Matlab, anyone here can tell me how to perform it? (Build-in functions?)

For example, I have the following frequency dependent data:

f X
f1 x1-jy1
f2 x2+jy2
f3 x3-jy3
...
....

Where fi,xi and yi are real numbers with particular value. How should I compute

f*dx/df in matlab?

Thanks in advance.
 

matlab discrete derivative

Hi,

cant you use diff instruction and then use array multiplication?

brmadhukar
 

discrete derivative matlab

Hello, brmadhukar:

Thank you for your reply.

The function diff() in matlab can only operate on real number arrary. Initially I had thought that the we cannot deal with complex number the same way we with the real number, thus posted the help here.

Later, I searched some materials on this topic and found that as long as one of the variable is real(here in my case is frequency:f), the finite difference that apply to real numbers still can apply to complex number(effectively treat real part and imaginary part of the complex number separately).

Thus, I can approximate dX/df=diff(X)./diff(f) assuming X is complex discrete data and the result will have a array length of (n-1), assuming the original array X has a length of n.

Regards,
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top