Hi,

I'm trying to produce the sinc roll off a DAC (it's non flat frequency response) as shown in the below image. I've managed to plot it theoretically using scilab but now i need to prove it, by producing it using a for loop, but I'm not quite sure how to do this. Any help with this would be much appreciated.

Scilab code for Theoretical plot;

Fcar=100;
Roll = [sin(%pi/Fcar)/(%pi/Fcar),sin(10*%pi/Fcar)/(10*%pi/Fcar),sin(20*%pi/Fcar)/(20*%pi/Fcar),sin(30*%pi/Fcar)/(30*%pi/Fcar),sin(40*%pi/Fcar)/(40*%pi/Fcar),sin(50*%pi/Fcar)/(50*%pi/Fcar),sin(60*%pi/Fcar)/(60*%pi/Fcar),sin(70*%pi/Fcar)/(70*%pi/Fcar),sin(80*%pi/Fcar)/(80*%pi/Fcar),sin(90*%pi/Fcar)/(90*%pi/Fcar),sin(100*%pi/Fcar)/(100*%pi/Fcar)]; etc.......

plot(Roll);
xlabel('Time index n'); ylabel('Amplitude'); 
title('Sinc Roll Off'); 

rect=[1 -0.3 55 1.1];
zoom_rect(rect)

I have also managed to plot it using the following code;

stacksize('max')
FS=192000;
fout=1920;
t=0:1:FS;
sig=sinc(2*%pi*t*fout/FS);
//playsnd(sig,FS)
plot2d(sig)
//plot(sig)
rect=[0 -0.4 2000 1.3];
zoom_rect(rect)

Thanks in advance.

 

You may not be sure how to do it, but I am quite unsure what you are even trying to do. Could you explain what you are trying to accomplish a bit more clearly.