window function between program and math I'm newbie on signal processing.
I know when we program python with window function. (just signal multiply with window)
According to Harris paper


I know we change w with different window(blackman).
However in python fft(signal*window(blackman)).
Is there still window(rectangular) function when we do signal capture(fft) in programming?
I mean that dft(signal * blackman * rectangular).
The fact that you are using a time limited sample of the waveform is the rectangular window that is referenced. Since the fft operates on a time limited sequence, it is mathematically identical to a infinitely long duration of that sequence multiplied the rectangular window.