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From: "Sadik " <sadik.hava@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: To zero pad a signal using MATLAB
Date: Mon, 25 May 2009 15:36:01 +0000 (UTC)
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What is z by the way in

plot([t z],...

I believe you had better write like this as I wrote just before your reply:

plot(0:0.001:0.512,...

in that line.



"Malcom Smith" <jreal_kko@yahoo.com> wrote in message <gved8f$4p5$1@fred.mathworks.com>...
> "Malcom Smith" <jreal_kko@yahoo.com> wrote in message <gve9m1$n8d$1@fred.mathworks.com>...
> > Hi there,
> > 
> > I'm trying to extend the following data set to 512 points by zero padding:
> > 
> > x(t)=100sin(2*pi*100*t)+2sin(2*pi*184.25*t)+randn(size(t)) where the sampling frequency is 1 kHz and 64 samples are available.  
> > 
> > Could you please provide me a code for implementing the zero padding and also plotting the resultant signal?
> > 
> > Many thanks in advance.
> 
> Please find below the code I have tried  (I'm simply not getting the output I need):
> 
> figure(10)
> subplot(1,2,1);
> f1=100;
> f2=184.25;
> fs=1000;
> t1=0;
> tstep=(1/fs);
> t2=63/fs;
> t=[t1:tstep:t2];
> x=100*sin(2*pi*f1*t)+2*sin(2*pi*f2*t)+randn(size(t));
> y=[x, zeros(1,(511*tstep))]; 
> plot([t z],y);
> subplot(1,2,2);
> Pxx=periodogram(x);
> Hpsd = dspdata.psd(Pxx, 'fs',fs);
> plot(Hpsd);
> datacursormode on
> 
> Could someone (other than Matt-xys@whatever.com) please help me on this.
> 
> Many thanks in advance.