Matlab for Signal Processing: Understanding 0:79 in Freq=(0:79)/(2*n*dt)

[babistopher]

Hi,

I am pretty new to Matlab and am trying to reduce the noise of a particular signal. I found this pdf online and found it to be helpful. However, I am having trouble figuring out what the freq=(0:79)/(2*n*dt) means. More specifically the 0:79 bit. Any help would be much appreciated.

Referring to: http://www.math.uic.edu/~jan/mcs320s07/matlec7.pdf

 

[marcusl]

(0:79) defines a string of the numbers from 0 to 79. The line defines "freq" as these numbers divided by the denominator.

 

[babistopher]

Thanks for the reply. I apologize that my question wasn't clear. I meant why are they choosing 80 samples?

 

[marcusl]

I think it's just a choice of convenience. If you plotted all 401 points in the spectrum, the peaks at bins 2 and 4 would be indistinguishable from the y axis. He's just zooming in on the region of interest.

 

[babistopher]

that's exactly what i figured. thank you.

 

[vky]

Hi, jus came across this thresd, noticed your MATLAB lecture notes seems very handy. I'm wondering if I would be able to get my hands on the set of notes your using. Wil be much apreciated if so. Thanks.