MATLAB Simulating RC Low Pass Filter Using MATLAB: Symbolic to Numeric Conversion

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To simulate a simple RC low pass filter in MATLAB, the user is attempting to filter a signal using the s-domain representation of the circuit. The process involves taking the FFT of the signal, multiplying it by the transfer function, and then using the IFFT to obtain the filtered output. The challenge arises from needing a numeric representation of a symbolic transfer function. The discussion highlights the importance of generating a Bode plot to analyze the system's frequency response, which can be done using the MATLAB Controls Toolbox. A provided tutorial link was particularly helpful in resolving the user's queries.
sinusance
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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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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/helpdesk/help/toolbox/control/ref/bode.html

An example:
http://www.engin.umich.edu/group/ctm/freq/freq.html
 
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Thanks a million MATLABdude,
That tutorial held all the answers and more! :)
 

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