Dealiasing in 2D: How to Effectively Use the 2/3 Padding Rule

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jollage
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Hi,

I would like to use the 2/3 padding rule for the dealiasing. In 1D, it's straightforward. For 2D, do I just have to set the highest 1/3 frequency components zero in both directions? For example, I ffted a 7*7 real data in Matlab, then I set the 4th and 5th columns and rows (corresponding to the highest 1/3 frequencies) to be zero. Is this ready for doing dealiasing? Thanks.
 
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If you FFT real data, then half of your resulting spectrum is redundant and can be ignored. I wouldn't set it to zero. Just ignore it.
If you are using zero padding, then you can zero pad in both directions. 7*7 seems awfully small for frequency analysis, but I guess it can be done.