How to plot the large set of fft matrices , no. of matrices is i.

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Amit 2012-2-4

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编辑： Azzi Abdelmalek 2013-9-29

plz help

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Amit 2012-2-4

I need t display them all at the same time

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Walter Roberson 2012-2-4

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This appears to be the same question as your http://www.mathworks.com/matlabcentral/answers/27995-plot-matrices . I proposed a method there a number of hours ago. If that method was not satisfactory then you should indicate more clearly what you would like to see.

Remember, a mesh is a 3D plot, so if you are going to plot a series of meshes, you need to decide how you want each one to appear relative to the other.

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Walter Roberson 2012-2-4

Assuming your array of fft results is named "a" as in your earlier fft question, and assuming that it is the third dimension that selects the plot number, as in that earlier question:

aabs = abs(a);

maxmag = max(aabs(:)) * 1.03; %3 percent spacing between plots

numplots = size(a,3);

zoff = 0;

for P = 1 : numplots

mesh(aabs(:,:,K) + zoff);

hold on

zoff = zoff + maxmag;

end

Note: if your data matrices have not each been normalized to have a mean of 0, then the maximum magnitude for any one fft() is quite likely going to occur at fft output bin index 1, which will have a value of the mean of the signal multiplied by the number of points in the signal (e.g., the total energy that the mean contributes.) For typical non-normalized signals, this first bin will be hundreds of times the rest of the coefficients, giving a spike there that makes everything else hard to see.

The code I gave here assumes that you know what you are doing and will *not* attempt to squish those peaks. The code will space the meshes in Z by a constant Z increment to the base, such that there is no possible Z overlap in drawing the meshes.

If you prefer a different spacing strategy, you can adjust the maxmag calculation.

Amit 2012-2-4