[x, y] = meshgrid(-2:0.02:2);
xyf = sin(30*(x));
When plotting fft(xyf) and abs(fft(xyf)), I get this results:
(see attachment)
Because of x and y as vars, I'm now a bit confused and unsure about the axis. Could you help me out, explaining the notation convention that is used. Additionally, I would like to now, what we can see / interpret, now we have these plotted results.
hello ,
I dont understand why do you want to plot a 2D Function , using 1D example ...
xyf = sin(30*(x)); is only depending on x variation, in this case size(x,1) times the same thing ...
First, look at x & y structure (take off ";" at the end of the line) , try plot(xyf). I thinks this will be helpful for better understanding;
best regards
O DANIEL
This question is very old and i do not know whether Daniel is still wane to get an answer for it. It may useful for the others to answer it. The function in the example is not a 2-D it is one dimensional. It can be expressed in the form sin 2 pi x/ lambdax, comparing with the example brought by Daniel we get 30= 2 pi/lambda,
resulting in lambda= 2 pi /30= 0.209. So in the range from -2 to 2 we have 20 wavelengths. Which is a long sufficiently long window to resolve the wave length.
In order to represent the sine wave one has to make the sampling interval lamba/2. As we decrease the sampling interval we can get we can get more frequency samples in the the ifft analysis. All want you need is make a one dimentional plot representing the amplitude versus frequency.
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