check what is signal and what is artifact.

A wavelet is like a *lens* through which we view the variability in both time *and* frequency.  All lenses will distort in some way, but you can't *not* choose a lens!

Therefore, you have to understand the nature of the artifacts introduced by the lens.

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#Summary, Part I

(i) The sampling model

`\[  z_n \equiv z(\Delta n),\quad\quad n=0,1,\ldots,N-1  \]`

(ii) Euler's formula

`\[  e^{i\omega t} = \cos(\omega t) +