Editing Poisson summation formula (section)

===Sampling===
In the statistical study of time-series, if <math>s</math> is a function of time, then looking only at its values at equally spaced points of time is called "sampling."  In applications, typically the function <math>s</math> is [[bandlimiting|band-limited]], meaning that there is some cutoff frequency <math>f_o</math> such that <math>S(f)</math> is zero for frequencies exceeding the cutoff: <math>S(f)=0</math> for <math>|f|>f_o.</math> For band-limited functions, choosing the sampling rate <math>\tfrac{1}{T} > 2 f_o</math> guarantees that no information is lost: since <math>S</math> can be reconstructed from these sampled values. Then, by Fourier inversion, so can <math>s.</math> This leads to the [[Nyquist–Shannon sampling theorem]].<ref name="Pinsky"/>