# How to use hanning window to get 5 cyles of sine waves?

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Kaleesh Bala on 12 Aug 2019
Commented: mm99 on 28 Dec 2019
t = 0: 10 * pi; % 5 cyeles
sf = 200e3; % frequency
sinewave = sin (2 * pi * sf * x); % gen continuous sine waves
w = hanning (length (sinewave)); % hann
figure (1);
plot (w);
% I do not know where to include the 5 cycles here

Andrey Kiselnikov on 12 Aug 2019
Edited: Andrey Kiselnikov on 12 Aug 2019
First of all you should properly define your data: "t = 0: 10 * pi; % 5 cyeles" I assume that you would like to define something like this "t = 0:1/sf:10*pi", more over "t" never used. Can you describe your task more properly?
>> t = 0: 10 * pi
t =
Columns 1 through 17
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Columns 18 through 32
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Kaleesh Bala on 12 Aug 2019
this gives me a modulated signal (increasing-decreasing)
f = 200*10^3; % sine frequency[Hz]
n = 5; % number of sine periods [-]
T = 1/f; % sine period [s]
tt = n*T; % total time [s]
burst = sin(2*pi*f*x) .* hanning(size(x,2))';
plot(x,burst);
but it's not correct as it should be only for 5 signals and then rest of the vecot should be '0'( a flat signal)
Kaleesh Bala on 12 Aug 2019
So,how to make it to start as modulated signal and then after 5 cycles to be flat signal =0
mm99 on 28 Dec 2019
Hi!
Did you get the result? I need the same thing and stucked in the same moment.