Using the DFT: Difference between revisions

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[[Image:Signals-13.jpg]]
[[Image:Signals-13.jpg]]







Script for matlab:
Script for matlab:


<pre>
clear all;
clear all;
t=0:.01:1;
t=0:.01:2;
T=0.20;
T=1/3;
ts=0:T:1;
ts=0:T:2;
f1=2;
f1=2;
f2=1/0.125;
f2=1/0.125;
x = sin(2*pi*3*t); %this is the function
x = sin(2*pi*ts); %this is the function
plot(t,x); % plot the original signal
plot(ts,sin(2*pi*ts),'r-',t,sin(2*pi*t)); % plot the original signal and the signal sampled at 3Hz
X = fft(x); % take the DFT
X = fft(x); % take the DFT
pause (2);
pause (2);
plot (t,X); %plot the DFT of the signal
plot (ts,X); %plot the DFT of the signal sampled at 3Hz
pause (4);
</pre>
x=sin(2*pi*t);
plot(t,x);
pause(2);
X = fft(x);
plot(t,X); %plot the DFT of the original signal

Revision as of 10:09, 27 November 2007

sampling and taking the DFT we get this graph:

Signals-13.jpg



Script for matlab:

clear all; t=0:.01:2; T=1/3; ts=0:T:2; f1=2; f2=1/0.125; x = sin(2*pi*ts); %this is the function plot(ts,sin(2*pi*ts),'r-',t,sin(2*pi*t)); % plot the original signal and the signal sampled at 3Hz X = fft(x); % take the DFT pause (2); plot (ts,X); %plot the DFT of the signal sampled at 3Hz pause (4); x=sin(2*pi*t); plot(t,x); pause(2); X = fft(x); plot(t,X); %plot the DFT of the original signal