MATLAB: Can anyone explain the difference between fft and freqz commands
digital signal processing
can anyone explain the difference between fft and freqz commands?
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It is hard to resist to answer "yes".
Let's assume that you've read the docs of both command already. Whilefreqz replies the "Frequency response of digital filter",fft determines the "Fast Fourier transform". The first command takes filter coefficients as input and the number of points for the response, while the later gets a signal as input.
Does this help already? If not, please edit the question (not as comment) and add any details about why you compare these 2 different functions. Perhaps it helps, when you explain what you see as similarities.
There is really not much difference between the two. If you are referring to the differences between the null depths, it is because the two use different default values of FFT points. The default of freqz is a 512-point FFT while for fvtool, it's 8192 points. If you use
if you look up the documentation you'll see what the inputs mean. both will give you different P's of the input sizes m x n of random numbers between 0 and 1.
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