DFT using MATLAB

[passionatekiss]

1. Use MATLAB to compute the DFT { d0 , d1 , d2 , d3 , d4 , d5 , d6 , d7 } for the following

data and plot the data

y0 = 0.324

y1 = 0.456

y2 = 0.112

y3 = 0.202

y4 = 0.654

y5 = 0.234

y6 = 0.678

y7 = 0.867

 

2. Plot the trigonometric polynomial tn(x).

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for the 1Q: I have this so far.

so far. i have this:

y=[0.324 .456 .112 -0.202 -.654 .234 .678 .867];

x=[0, pi/4, pi/2, 3*pi/4, pi, 5*pi/4, 3*pi/2, 7*pi/4]

plot (x,y)

 

Is that right?

 

 

But for the 2, I have no idea how to get started with the MATLAB. I googled it, but no useful info is found.

 

Please someone help me. Thanks a lot.

[cypress]

I believe the answer to your question lies in an understanding of sampling theory. In DFT, X(t) can be reconstructed by summing the shifted and scaled component parts of the sinc function, this should provide some understanding of the time tn for a given sample value x.

 

Here is a link that may help you understand what is being asked of you.

[passionatekiss]

I believe the answer to your question lies in an understanding of sampling theory. In DFT, X(t) can be reconstructed by summing the shifted and scaled component parts of the sinc function, this should provide some understanding of the time tn for a given sample value x.

 

Here is a link that may help you understand what is being asked of you.

 

Thank you for the info... But what is j? How can i enter the whole trig poly function?

 

And is the one I did for the first one correct? Thanks a lot.

[passionatekiss]

Thank you for the info... But what is j? How can i enter the whole trig poly function?

 

And is the one I did for the first one correct? Thanks a lot.

 

Nvm I got it!