are the low-pass filter and the sharp cut-off filter the same thing??
Here there is the definition of sharp cut-off filter https://en.wikipedia.org/wiki/Filter_(large_eddy_simulation) .
I tried to obtain with matlab the Fourier transform of the low-pass filter, but I noticed that I don't reach the low pass filter. What am I doing wrong?
x=-100:0.1:100 delta=5 G=sin(pi*(x+eps)/delta)./(pi*(x+eps)) H= abs(fft(G)) Tinc=0.01 Fs=1/Tinc; freq =transpose( -Fs/2:Fs/length(G):Fs/2-(Fs/length(G))); figure() plot(x,G) figure() plot(freq,H)