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Subject: Box car Filter
Date: Sat, 18 Jul 2009 19:54:01 +0000 (UTC)
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I have following things

N=64;
dt=.01;
t=dt*[-N/2:N/2-1]

Ts=.01;%Sampling time interval
Fs=1/Ts;%Fs=100

fo=4; %Sampling of a sine wave
w=2*sin(2*pi*fo*t)+2*sin(2*pi*2*t);
freq=[-N/2:N/2-1];

1.w=Spectra of signal (1 by 64)
2. s=Spectra of spike (1 by 64)
3.C= Convolution of above two (w*s)(127 by 1)
4. Now i want to construct my spectra back with mulipying with Box car How  can i do it. I dont know how to multiply my constructed box car with C

I am constructing a box car with
N=64;
dt=.01;
t=dt*[-N/2:N/2-1]

Ts=.01;%Sampling time interval
Fs=1/Ts;%Fs=100

fo=4; %Sampling of a sine wave
w=2*sin(2*pi*fo*t)+2*sin(2*pi*2*t);
freq=[-N/2:N/2-1];

x_range=[0:1:63]
box=zeros(1,64)
select = find(x_range>24 & x_range<40);
box (select)  = ones(size(select))
plot(f,box)


After that what should i do, how i can multiiply convolved function 
which is 127 by 1 with box car which is 1 by 64



Also

Size of C (conv function) in time domain is 1 by 64, as in time domain i have done multiplication now how should i want to convolve this with my FFT of boxcar..so that i can construct the signal back n both domains.

Thanks



How can i do it