MATLAB symbolic to numeric


by sinusance
Tags: fft, matlab, numeric, symbolic, transfer function
sinusance
sinusance is offline
#1
Mar31-09, 01:32 PM
P: 4
hey,

I'm trying to use matlab to simulate a simple RC low pass filter. I have an array of data that represents the signal I want to filter, and I have the s-domain representation of the filter circuit. I'm pretty new to this type of analysis, but I'm pretty sure I should be taking the fft of my data and multiplying it by the s-domain representation (transfer function) of the circuit, and then take the ifft to get the output.
I guess my problem is I have a symbolic transfer function that I'm trying to multiply with a numeric array. Any Ideas on how I can get a numeric representation of my symbolic transfer function?

Thanks in advance.

(this is my transfer function if that helps)
transferFunc = 100/(s+100)
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MATLABdude
MATLABdude is offline
#2
Apr1-09, 03:37 AM
Sci Advisor
P: 1,724
You probably want something called a Bode plot (magnitude and phase angle of a Linear Time Invariant system):
http://en.wikipedia.org/wiki/Bode_plot

If you have the MATLAB Controls Toolbox, you can generate a Bode plot of a system given its transfer function:
http://www.mathworks.com/access/help.../ref/bode.html

An example:
http://www.engin.umich.edu/group/ctm/freq/freq.html
sinusance
sinusance is offline
#3
Apr5-09, 06:38 PM
P: 4
Thanks a million MATLABdude,
That tutorial held all the answers and more! :)


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