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5 votes
1 answer
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The discrete Fourier transform's Gaussian-like eigenvector

I have the $N$x$N$ matrix below where $N$ is a power of 2 (usually 64 or 256) and $\omega = 2\pi/N$. What is its largest eigenvalue? $\begin{bmatrix} 2 & 1 & 0 & 0 & \cdots & 0 &...
bobuhito's user avatar
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22 votes
2 answers
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Fast Fourier transform for graph Laplacian?

In the case of a regularly-sampled scalar-valued signal $f$ on the real line, we can construct a discrete linear operator $A$ such that $A(f)$ approximates $\partial^2 f / \partial x^2$. One way to ...
TerronaBell's user avatar
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